CN103370154A

CN103370154A - A superhard structure and method of making same

Info

Publication number: CN103370154A
Application number: CN2011800674776A
Authority: CN
Inventors: 穆萨·马霍姆·阿迪亚; 杰弗里·约翰·戴维斯; 大卫·克里斯蒂安·鲍思
Original assignee: Element Six Abrasives SA
Current assignee: Element Six Abrasives SA
Priority date: 2010-12-31
Filing date: 2011-12-20
Publication date: 2013-10-23
Also published as: GB2486974A; GB2486974B; US20130344309A1; GB201121921D0; CA2822828A1; EP2658667A1; JP2014506297A; US20170183761A1; GB201022127D0; WO2012089566A1

Abstract

A superhard structure comprises a body of polycrystalline superhard material comprising a first region and a second region, the second region being adjacent an exposed surface of the superhard structure, the second region comprising a diamond material or cubic boron nitride, the density of the second region being greater than 3.4x103 kilograms per cubic metre when the second region comprises diamond material. The material(s) forming the first and second regions have a difference in coefficient of thermal expansion, the first and second regions being arranged such that this difference induces compression in the second region adjacent the exposed surface. The first/a further region has the highest coefficient of thermal expansion of the polycrystalline body and is separated from a peripheral free surface of the body of polycrystalline superhard material by the second region or one or more further regions formed of a material or materials of a lower coefficient of thermal expansion. The regions comprise a plurality of grains of polycrystalline superhard material. There is also disclosed a method of making such a material.

Description

Superhard structure and manufacture method thereof

Technical field

The present invention relates to comprise the superhard structure of polycrystalline material body, the method for making superhard structure and the anti-wear component that comprises the superhard structure of polycrystalline.

Background technology

Thereby can when a certain amount of diamond particles with selected average grain size and distribution of sizes being applied high pressure and high temperature, make it contact the hard metallic matrix that is pre-existing in and make polycrystalline diamond abrasive compact (PCD).The typical pressure of using in this process is between 4 to 7GPa, and still the more high pressure up to 10GPa also is feasible in practice.The temperature that adopts is higher than the fusing point of transition metal binding agent under such pressure of hard metal matrix.For the common situations that uses the tungsten carbide/cobalt matrix, be higher than 1395 ℃ temperature and be enough to melt metal in the binding agent, cobalt for example, it infiltrates in described a certain amount of diamond particles, can make diamond particles generation sintering.The PCD material that generates can be considered to the continuous net-shaped thing that runs through mutually net of the combined crystal grain of diamond and adhesive, for example cobalt-based metal alloy.And then by pressure and temperature being reduced to indoor conditions to PCD material (its formation is attached to the PCD platform on the matrix) quenching of such formation.At the temperature during quenching, the metal freezing in the adhesive, and PCD platform and matrix are combined.Under these conditions, PCD platform and matrix can be considered to mutually be in the thermoelasticity poised state.

Typically, but not uniquely, the cutting element or the cutter that are used for boring, drilling or mining industry application comprise being attached to polycrystalline diamond (PCD) material layer that the diamond table form on larger matrix or the body exists, and described larger matrix or body are made by the tungsten carbide/cobalt sintering metal usually.This cutter with supporting carbide substrate is manufactured to the straight circular cylinder type with polycrystalline diamond layer or platform traditionally and usually, the thickness range of described polycrystalline diamond layer or platform be 0.5mm to 5.0mm, be between the 2.5mm but more at 1.5mm.Metallic matrix typically is 8mm to 16mm length firmly.The diameter of straight cylinder cutter commonly used is in 8mm arrives the scope of 20mm.

Also use other PCD structure (such as general dome-shaped and pick up linear element) in various application, these are applied as for example drilling, mining and road surfacing and use.Usually, form the PCD material outer layer at this element with metal carbides, this PCD material outer layer is used as being attached to the matrix on this element.In addition, the matrix largest portion of this class formation normally.

Normally, use the bite type of this type of cutter to be called chipping type bit.In such drill bit, several PCD cutters are arranged on the drill body, so that a part of top periphery edge of each PCD platform weares and teares in the rock stratum.Because the rotation of drill bit, the top periphery edge experience of each PCD platform of each cutter loads and wear process subsequently, and this wear process causes limited amount PCD material to be removed gradually.Eroded area on the PCD platform is called as polishing scratch.

In drilling operating period, the performance of PCD cutter is by the germinating of the crackle in the PCD platform and diffusion and definite to a great extent.The crackle that also intersects with it towards the diffusion of cutter Free Surface can cause cutter to split, and this moment, the PCD of bulk fractureed from the PCD platform.The result of this phenomenon may reduce the service life of drill bit, and may cause the bust of cutter.

Expectation can stop or suppress the formation of any crackle, or makes crackle generation deflection and can the bulk diffusion by the PCD platform not arrive Free Surface, thus the prolongation cutting-tool's used life.

International Patent Application WO 2004/111284 discloses a kind of composite, and this composite comprises a plurality of nuclear cores and suitable adhesive, and each nuclear core comprises single PCD particulate, and these nuclear cores are dispersed in the matrix, and this matrix coats this single particulate.Matrix is different from the PCD material of examining core by grade and forms.

Other known solution relates to the ways to restrain of for example processing Cracking behavior by the mode of certain layer design directly or indirectly.

For the solution of routine, need polycrystalline superhard material to have favourable residual stress distribution, it can improve the crackle diffusion of not expecting and therefore extenuate spallation.

Summary of the invention

From first aspect, the invention provides a kind of superhard structure, comprising:

The polycrystalline superhard material body, this body comprises:

The first area; And

Second area, the exposed surface of second area and superhard structure is adjacent, and second area comprises diamond or cubic boron nitride, and the density of second area is greater than 3.4 * 10 when second area comprises diamond ³Kg/m ³And

Wherein, one or more materials that form the first and second zones have different thermal coefficient of expansions, and the first and second zones are configured such that the difference between its thermal coefficient of expansion causes compression in the second area adjacent with described exposed surface; And wherein, first area or other zone have the maximum heat coefficient of expansion of polycrystalline body, and this first area or other zone are by the second area that formed by one or more materials with less thermal coefficient of expansion or one or more other zone and separate with the peripheral Free Surface of polycrystalline superhard material body; Wherein, each zone comprises a plurality of polycrystalline superhard material crystal grain.

From second aspect, the invention provides a kind of method of making the superhard structure of polycrystalline, the method comprises:

A) first area of formation polycrystalline material;

B) form with as the first area of exposed surface second area adjacent, polycrystalline material, second area comprises polycrystalline diamond or cubic boron nitride; Wherein, one or more materials that form the first and second zones have one or more difference in physical property;

C) the first and second zones are applied the pressure that is higher than 4GPa and the temperature that is higher than 1200 ℃ and reach the scheduled time;

D) pressure and temperature is reduced to environmental condition, so that described one or more difference on physical property cause compression in the second area adjacent with described exposed surface; Wherein, first area or other zone have the maximum heat coefficient of expansion of polycrystalline body, and this first area or other zones are by the second area that formed by one or more materials with less thermal coefficient of expansion or one or more other zone and separate with the peripheral scope of freedom of polycrystalline superhard material body; Wherein, each zone comprises a plurality of polycrystalline superhard material crystal grain.

From the third aspect, the invention provides drill bit or the cutter that comprises superhard structure described here or the assembly that is used for drill bit or cutter.

Description of drawings

Fig. 1 is the cross sectional representation of planar interface PCD cutter, and dash area has been described the zone of the preferential diffusion of crackle among the figure;

Fig. 2 a is according to half cross sectional representation the first embodiment, that be connected to the PCD body on the matrix;

Fig. 2 b is the three-dimensional display of partial cross section of the embodiment of Fig. 2 a, and it has shown that with section the inside of zones of different arranges;

Fig. 3 is according to half cross sectional representation the second embodiment, that be connected to the PCD body on the matrix;

Fig. 4 is according to half cross sectional representation the 3rd embodiment, that be connected to the PCD body on the matrix;

Fig. 5 is according to half cross sectional representation the 4th embodiment, that be connected to the PCD body on the matrix;

Fig. 6 is according to half cross sectional representation the 5th embodiment, that be connected to the PCD body on the matrix;

Fig. 7 is according to half cross sectional representation the 6th embodiment, that be connected to the PCD body on the matrix;

Fig. 8 is according to half cross sectional representation the 7th embodiment, that be connected to the PCD body on the matrix;

Fig. 9 is according to half cross sectional representation the 8th embodiment, that be connected to the PCD body on the matrix;

Figure 10 is according to half cross sectional representation the 9th embodiment, that be connected to the PCD body on the matrix;

Figure 11 is according to half cross sectional representation the tenth embodiment, that be connected to the PCD body on the matrix;

Figure 12 is according to half cross sectional representation the 11 embodiment, that be connected to the PCD body on the matrix;

Figure 13 is according to half cross sectional representation the 12 embodiment, that be connected to the PCD body on the matrix;

Figure 14 a, b, c are the stress distribution schematic diagram in the conventional planar cutter of only being made by a kind of PCD material, it has shown respectively axially, radially with the tensile stress field of hoop and the position of compression field and maximum tension and maximum pressure;

Figure 15 is according to the half cross sectional representation embodiment among Fig. 7, that be connected to the PCD body on the matrix;

Figure 16 a, b and c be for according to schematic diagram a kind of embodiment, that shown the stress distribution in the cutter, it has shown respectively axially, radially with the tensile stress field of hoop and the position of compression field and maximum tension and maximum pressure;

Figure 17 be the top periphery edge of cutter and adjacent with the embodiment of Figure 16 a and near the schematic three dimensional views of material profile;

Figure 18 is the optical microscopy map corresponding to half cross section of the wearing and tearing cutter of Figure 15 about embodiment 5, and Figure 15 is according to the embodiment among Fig. 7; How much settings that can be clear that this PCD material of two types are denoted as volume 1 and volume 12, and the polishing scratch after the laboratory simulation rock drilling is denoted as 17, and main crackle is denoted as 18;

Figure 19 is about embodiment 6 and has shown the layout of different materials in the embodiment of embodiment 6;

Figure 20 is the optical microscopy map corresponding to half cross section of the wearing and tearing cutter of Figure 19 about embodiment 6, and it has indicated polishing scratch and main crackle;

Figure 21 has shown the layout of three kinds of different PCD materials in the embodiment of embodiment 7;

Figure 22 is the optical microscopy map corresponding to half cross section of the wearing and tearing cutter of Figure 21 about embodiment 7, and it has indicated polishing scratch and main crackle.

The specific embodiment

" superhard material " used herein is the material that Vickers hardness is at least about 25GPa.Diamond and cubic boron nitride (cBN) material is the embodiment of " superhard material ".Diamond is the hardest known materials, and cubic boron nitride (cBN) is considered to second in this respect.This bi-material all is called as superhard material.The hardness that they are recorded is obviously greater than nearly all other material.Hardness number is quality factor, and wherein they highly depend on the method that adopts when measuring them.Loading 500g and use the measured adamantine hardness of Nu Shi identation hardness measuring technique under 298 ° of K is 9000kg/mm ², the hardness of boron nitride is 4500kg/mm ²When the use commercial measurement similar to Vickers or Nu Shi impression, the hardness of PCD material typically drops on 4000 to 5000kg/mm ²Scope in.Other for example the hardness that records in a similar manner of the hard material of boron carbide, carborundum, tungsten carbide and barium carbide be respectively 2250,3980,2190 and 2190kg/mm ²At this, for the purpose of discussing, measuring hardness greater than about 4000kg/mm ²Material be called superhard material.

Finish the manufacturing process of the cutter that comprises superhard material under high-temperature and high-pressure conditions after, locking its inner residual stress, to be considered to especially the germinating of crackle between operating period with cutter especially relevant with diffusion.Because the elastic modelling quantity and the thermal coefficient of expansion that differ widely between superhard material (for example PCD material) and the matrix, can form very large residual stress when being quenched into room temperature and pressure condition finishing.Although the superhard material platform is under the reduced overall state now, the curvature effect that causes when Jiang Tai is bonded to a side of matrix can cause the local tensile stress in the critical zone of platform.

Observe from laboratory and the field trial of PCD cutter, along with the wearing and tearing of cutter, the crackle in the PCD material produces in some critical zone and spreads.Crackle especially is easy to germinate on the surface of polishing scratch or followed by polishing scratch.Behind the crack initiation, they are diffused in the PCD material body, or are parallel to the top of PCD platform, or turn to top or the PCD carbide substrate interface of PCD platform.Turn to the crackle of PCD material surface might cause the cracked or spallation of PCD platform or lose most of PCD material, this has just reduced life-span and the stock-removing efficiency of cutter.Observe, if can stop, the diffusion of deflection crackle, or make it towards PCD carbide interfacial diffusion, or usually, make it away from the surface of PCD material, then cutter life can prolong.

The variation of stress distribution in each zone has been described here, the diffusion of crackle in these zones is believed to be helpful in the further diffusion that suppresses crackle or helps to make crackle to depart from their preferential critical zones of spreading, or crackle is limited in the so not disadvantageous preferred volume of cutter life or the zone.A kind of stress of the PCD of manipulation material has been described so as to cause the compression in the critical zone or reduce in the critical zone method.As selecting and in addition, the maximum tensional stress in the critical zone may be removed and away from Free Surface.The material that the position of former critical zone is in compressive state at this moment occupies.By placing the polycrystalline material (such as the PCD material) of the pressure with increase and the tension force that reduces in crack path, can realize with the crackle transmission or deflect into to have the more effect in the zone of high-tension.Such transmission or deflection preferably guide crackle away from the Free Surface of superhard material (such as the PCD material).

For the suitable position in the PCD of cutter platform causes compression, during manufacturing process, make the different materials adjacency with different characteristic.This comprises the character of thermal coefficient of expansion for example and/or elastic modelling quantity or any other physical property, and after manufacturing process, these character will cause a kind of material to cause the compression of the another kind of material that is adjacent, and automatically enters tension state or reduce compressive state.

If two kinds of different materials of thermal coefficient of expansion are connected then cooling during the high temperature manufacturing process, the material that then has larger thermal coefficient of expansion can shrink manyly than another material.It is to produce compression stress in having the material of relatively low thermel expansion coefficient that the material that contraction with material of larger thermal coefficient of expansion is had a less thermal coefficient of expansion suppresses the result.

Another mode that causes compression in material is the material adjacency that makes different elastic modelling quantity during the high pressure manufacturing process.When release pressure, the material with higher elasticity modulus will cause the compression that has than the material of low elastic modulus, and its tension force will increase automatically.

The cutter that comprises such as the PCD material body can use high temperature and in conjunction with the high pressure manufacturing, cause the method for compression more than wherein using.

It is all different significantly on thermal coefficient of expansion and elastic modelling quantity to have observed some PCD material types.In these materials, when thermal coefficient of expansion hour, elastic modelling quantity is just large.Therefore, when the different materials that adopts from this group, the high temperature and high pressure quenching during the material forming can cause opposite stress-induced effect.Yet the STRESS VARIATION effect that the thermal coefficient of expansion difference is brought accounts for leading.

Also observe, although other PCD material types have significantly different thermal coefficient of expansion, little and relatively inessential difference can only be arranged on elastic modelling quantity.When using such PCD material, the different institutes of elastic modelling quantity produce an effect may be left in the basket to a great extent.

In order to help further discussion, use circular cylindrical coordinate with the residual stress of the PCD layer of cylindrical cutting tool resolve into respectively along tool axis, along tool radius and along radius tangent axially, radially and circumferential component.

Illustrate the preferential critical zone of germinating and/or spreading crackle in the typical conventional tool among Fig. 1.These critical zones may be different on tensile stress position, size and Orientation, and the possibility quilt is as giving a definition:

1. the zone of crack initiation namely, with peripheral surf zone, is shown as regional A1 and A2 in the polishing scratch among Fig. 1.The exemplary position of polishing scratch is shown in chain-dotted line X-Y among Fig. 1.The zone of zone A1 indication crack initiation in the initial stage of tool wear, and regional A2 indication is the later stage of wearing and tearing.Zone A1 relates to the hoop tensile stress and A2 relates to axial tensile stress.

2. crackle is in diffusion in the zone of the top surface of PCD material and cause that cutter splits too early, and this zone is expressed as regional B1 and B2 in Fig. 1.The same with regional A1 and A2, regional B1 and B2 be early stage relevant with the later stage with wearing and tearing respectively.B1 is relevant with radial and axial tensile stress with B2 in the zone.

3. towards the PCD material center zone on carbide substrate just, cutter fully after the wearing and tearing some crackles diffuse into this zone, shown in the regional C among Fig. 1.The harmfulness that is diffused into the crackle in this zone is less because they can be on PCD material Free Surface flared.C is relevant with less axial tensile stress in the zone.

4. the regional D among Fig. 1 represents the cumulative volume of the PCD material outside the critical zone, and crackle obviously is not inclined in this zone and spreads.In this zone, hoop and radial stress be pressure normally, and axial stress is becoming compression from slight stretching in the radial direction.

Some position in the PCD platform has been determined in above-described critical zone, thereby different PCD material block can be placed on the residual stress distribution that change is caused by universal cutter structure and manufacturing process thereof on these positions.Change in the desired residual stress distribution relates in the critical zone and to produce compression or to reduce tension force.Selectively, the critical zone that is attended by maximum tensional stress can be transferred to from the Free Surface of PCD platform the internal volume of the PCD platform with less harmfulness.These of stress distribution change to be used for stop crackle, or are used for making crack deflection or crackle is directed to away from the subcritical zone of Free Surface and towards cumulative volume and the carbide interface of PCD platform.Thus, having reduced the generation that before impels PCD platform crackle spallation, that diffuse to Free Surface can make again cutter life obtain as desired prolonging.

Sign critical zone and arrangement help the redistribution of residual stress in superhard structure by the suitable material block of these zone indications.

Existence is with respect to the various ways of critical zone placement PCD material, by means of following embodiment description some combinations wherein.The variation of the residual stress that causes allow with part independently mode operate and change different critical zones, and can be used for representing the effect of each particular embodiment.

Fig. 2 a has shown the part schematic diagram of half cross section of superhard material (for example PCD material) body that is connected on the matrix, and it has indicated the adjacent block relevant with each zone among Fig. 1.These pieces may be comprised of the material of different structures, composition and relevant nature, thereby can change stress distribution.

Fig. 2 b is the three dimensional representation of 60 ° of profiles of the embodiment of Fig. 2 a, and it has shown the internal placement of zones of different.First area 1 among these figure mainly comprises the regional D among Fig. 1, and has occupied the cardinal principle center of PCD platform.Its

zone

2,3,4,5 and 6 adjacent by five and combination surrounds.The first volume 1 separates with the circumferential Free Surface of PCD platform by the 3rd zone 3, the 4 and the 5th zone 5, the 4th zone.Matrix is designated 7.The 6th zone 6 is placed on (this matrix can be such as carbide substrate) between the first central area 1 and the matrix 7, and relevant or corresponding with regional C among Fig. 1.The 3 and the 6th zone 2, the 3rd zone is adjacent, and arranges with the circumferential Free Surface of matrix 7 and PCD platform is contiguous.This zone is relevant with the regional A2 of Fig. 1.

The 4 and the 3rd zone 3, the 4th zone is adjacent, and is positioned at the circumferential Free Surface of PCD platform.Zone 4 is relevant with the A1 zone of Fig. 1.The 5th zone the 5 and the 4th regional 4 is adjacent and first area 1 and the top Free Surface of PCD platform are separated.The 5th zone 5 is relevant with regional B1 among Fig. 1.

Second area 2 is adjacent with the 5th zone 5, and first area 1 and the remainder of the top Free Surface of PCD platform are separated.Second area 2 extends across the mid portion of the top Free Surface of PCD platform, and relevant with the regional B2 of Fig. 1.

The material that can select to have the maximum heat coefficient of expansion is filled first area 1 or the 6th zone 6.For example, in some embodiments, first area 1 can comprise the material with maximum heat coefficient of expansion; Be chosen as second area 2 to the 6th zones 6 material can different on the thermal coefficient of expansion and on thermal coefficient of expansion all less than first area 1.

The thermal coefficient of expansion of the 5th regional 5 materials may be less than the thermal coefficient of expansion of the 4th zone 4 and second area 2.Similarly, the thermal coefficient of expansion of the material in the 6th zone 6 may be less than the thermal coefficient of expansion in the 3rd zone 3, and the thermal coefficient of expansion of the material in the 4th zone 4 may be less than the thermal coefficient of expansion in the 3rd zone 3.

Comprise for forming the employed material of zones of different, for example, comprise the diamond such as the material of PCD, have the composite of other metals such as copper, tungsten, have the composite such as the pottery of carborundum, titanium carbide and nitride etc.In addition, also can use and cutter structure and the manufacturing process compatible non-diamond that comprises mutually, and may comprise hard metal such as tungsten carbide/cobalt, titanium carbide/nickel etc., such as the cermet of the combination of aluminium oxide, nickel etc., general pottery and refractory metal.

Except the relative coefficient of thermal expansion differences of using material, also can suitably change stress field in the PCD cutter with elastic modelling quantity.In this embodiment, select to compare with the material in second area 2 to the 6th zones 6 material with minimal elastic modulus as the material of first area 1.Typical PCD material is usually all different on thermal coefficient of expansion and elastic modelling quantity.Be used for making under the high-temperature and high-pressure conditions of diamond sintering in the situation of PCD material, owing to the caused stress of thermal expansion mismatch typically accounts for leading.

In some embodiments, first area 1 ratio that accounts for the cumulative volume of PCD platform is enough to the stress in the peripheral region is produced significant impact.For example, first area 1 can occupy whole PCD stage bodies long-pending about 30 to 95%.Thereby can between each of second area 2, the 3rd zone 3, the 4th zone 4, the 5 and the 6th zone 6, the 5th zone adjacent boundary be set changes to optimize desired stress distribution.

Well known in the prior artly be that typically but be not uniquely, the PCD material has 3 * 10 ^-6To 5 * 10 ^-6Thermal linear expansion coefficient in the/℃ scope.

The poor embodiment of thermal linear expansion coefficient between each regional material in the material of first area 1 and second area 2 to the 6th zones 6 is at least about 0.3 * 10 ^-6/ ℃.Equally, the poor embodiment of thermal linear expansion coefficient between two kinds of adjacent materials is at least about 0.1 * 10 ^-6/ ℃.If zone 4 is to be made by the abundant high-abrasive material with enough cutting abilities (such as the PCD material etc.), can in other zone, use so other to satisfy thermal expansion standard and above-mentioned preferred hard material.

The PCD material can be considered to the combination of diamond and transition metal (such as cobalt, nickel etc.).Adamantine thermal linear expansion coefficient is very little, and literature value is 0.8+/-0.1 * 10 ^-6/ ℃.Metal such as cobalt has large thermal coefficient of expansion, and the typical heat coefficient of expansion of transition metal is for example 13 * 10 ^-6/ ℃.The thermal coefficient of expansion of typical PCD material extremely depends on the composition ratio of diamond and metal.In fact, the very easily method of making the PCD material variant with different heat expansion coefficient is to make significantly different PCD material of tenor.The tenor of PCD material may be typically, but be not unique, drops in the scope of 1 to 15 percent by volume, and can make metal volume percentage up to 25 material.

About the embodiment of illustrating among Fig. 2 a, the tenor of the PCD material in the first area 1 is greater than the PCD material of remaining area 2 to 6, thereby changes the stress distribution of PCD layer in the mode of expectation.In addition, the tenor in the 5th zone 5 may be than the 4th zone 4 and second area 2 little.The tenor of the material of second area 2 may be than the 3rd zone 3 little, the tenor of the material in the 4th zone 4 may equate than the little of the 3rd zone 3 or with it.

Difference between the tenor of the PCD material in the PCD material of first area 1 and second area 2 to the 6th zones 6 is at least about 1.5 percents by volume.In addition, the tenor of any adjacent materials in second area 2 to the 6th zones 6 is poor for for example at least about 0.5 percent by volume.

Tenor by the PCD material of the diamond particles manufacturing of large average grain diameter tends to lower than those PCD materials of being made by less average grain diameter.Therefore, in fact, by selecting the average grain diameter of diamond particles, can make the PCD material that has different metal content and be attended by different heat expansion coefficient.

In the embodiment shown in Fig. 2 a, the average grain diameter of the material of first area 1 may be for example little than the material in second area 2 to the 6th zones 6.

As a kind of selection, the average grain diameter of the material in the 6th zone 6 may be less than the average grain diameter of the material of all other zones (i.e. zone 1 to 5).

In some embodiments, the average grain diameter of the material of first area 1 drops in about 1 to 10 micron scope, and the average grain diameter of the material in other zone 2 to 6 is greater than about 10 microns.

In the similar situation of the thermal coefficient of expansion of the PCD of different structure material, can cause relative stress with different elastic modelling quantity.In such embodiments, the elastic modelling quantity of each other regional material of modular ratio of the material in the material of the first area 1 of Fig. 2 a or the 6th zone 6 is large.

Typically, but be not uniquely, the elastic modelling quantity of PCD material arrives in the scope of 1050GPa about 750.For example, the elastic modulus difference between the material in first area 1 or the 6th zone 6 and remaining each regional material is at least about 20GPa.

If the material in the 4th zone 4 is to be made by the very wear-resisting material with enough cutting abilities (such as PCD material etc.), can use so other to satisfy elastic modelling quantity standard and above-mentioned preferred hard material.

As previously mentioned, the PCD material can be regarded as comprising the combination of diamond and transition metal such as cobalt, nickel etc.Single-crystal diamond is one of hard material known to the mankind, and it has very large elastic modelling quantity.The PCD material comprises the diamond dust as its Main Ingredients and Appearance, and diamond dust may be that synthesize or natural, and with the gap symbiosis (intergrown) of being filled by transition metal.A kind of method that changes elastic modelling quantity is to change adamantine total content.Diamond content is higher, and elastic mould value is just larger.The diamond content of PCD material may be typically but is not to drop on uniquely in the scope of 75 to 99 percents by volume.

In these embodiments, elastic modulus difference accounts for leading in the generation of residual stress.Then, with reference to the embodiment of Fig. 2 a, the diamond content of the PCD material in first area 1 or the 6th zone 6 is greater than the diamond content of all the other regional PCD materials.

For example, the diamond content of the PCD material in first area 1 or the 6th zone 6 and the PCD material that all the other are regional is poor is at least about 0.2 percent by volume.

With reference to Fig. 2 a, the stress on the interface between the selected different materials in the adjacent area may be very high, produced stress gradient precipitous and that do not expect at these interfaces, and these interfaces self may be the positions of localized cracks germinating.In order to eliminate or to reduce this situation, wish to change gradually structure and composition between the adjacent material.Therefore thereby can select diamond content, particle diameter and tenor to taper to adjacent area from a zone, for example, the distance of crossing over is 3 times of maximum average grain diameter of material at least.

By selecting the material in the special volume and making it have same coefficient of thermal expansion, can realize other embodiment.

Fig. 3 is the schematic diagram of PCD cutter, and wherein first area 1 has identical and maximum thermal coefficient of expansion with the 6th zone 6, and second area 2, the 3rd zone 3, the 4th regional 4 have less and different thermal coefficient of expansions with the 5th zone 5.Material with maximum heat coefficient of expansion extends to PCD platform and carbide substrate at the interface, but still the circumferential Free Surface of the material by having less thermal coefficient of expansion and PCD platform separates.

Fig. 4 is the schematic diagram of PCD cutter, and its first area 1 also has the identical maximum heat coefficient of expansion with the 6th zone 6, but the material in second area 2, the 3rd zone 3, the 4 and the 5th zone 5, the 4th zone has the less thermal coefficient of expansion that is equal to each other.The PCD platform of cutter can be considered to be by two different zones of thermal coefficient of expansion and consist of, zone with maximum heat coefficient of expansion is symmetrical arranged about the axis of the interface face of PCD platform and matrix, and the Free Surface of the zone by having minimum coefficient of thermal expansion and PCD platform separates.

The cutters of making according to Fig. 2,3 and 4 can cause the axial tensile stress among the regional A2 of Fig. 1 obviously to reduce, and the radially tensile stress that causes the hoop tensile stress of regional A1 and regional B1 dorsad the Free Surface of PCD move.This embodiment shown in Fig. 3 and 4 can be respectively solves (address) seminess during the initial stage of tool wear and later stage.

Thereby comprising border between the adjacent area of different materials can be expanded and be formed for the separately new region of adjacent area.By this method, can adopt more complicated three dimensional design.Fig. 5 is the schematic diagram of cutter, wherein, border between the second area 2 of the first area 1 of combination in Fig. 4 and the 6th zone 6 and combination, the 3rd zone 3, the 4 and the 5th zone 5, the 4th zone is expanded, thereby generates the new separation volume that is denoted as Section Eight territory 8.In Fig. 5, in conjunction with first area and the 6th zone be denoted as now the 9th zone 9, and the second area of combination, the 3rd zone, the 4th zone and the 5th zone are now shown in the tenth zone 10.In one embodiment, Section Eight territory, the 9th zone and the

tenth zone

8,9,10 can be by the material manufacturings with different heat expansion coefficient.For example, Section Eight territory or the 9th zone 8 or 9 can be by the material manufacturings with maximum heat coefficient of expansion.

In some embodiments, the material in the 9th zone 9 has maximum thermal coefficient of expansion, the 8th with the 9th zone 8,9 different on thermal coefficient of expansion.Equally, the material in Section Eight territory 8 can have the intermediate heat coefficient of expansion between the 9th and the tenth zone 9,10.

Obviously reduce according to the axial tensile stress of cutter in the regional A2 of Fig. 1 of a rear embodiment manufacturing, thus so that the radially tensile stress of regional B1 be moved, and may be so that the circumference stress in the All Ranges shows as compression.The elimination of hoop tensile stress will be very favorable result.

By the expansion on border among Fig. 5, can realize having other modification in the different materials zone that quantity increases, shown in illustration A.In this way, Tool Design may develop into has four or five zones, still keeps the geometry of former interface boundary simultaneously.By continuing this border extension process, can form new zone, can develop the Tool Design that has a plurality of volumes but still keep former interface boundary geometry, as shown in Figure 6.

Can in a plurality of zones, construct the arrangement of a large amount of different materials.In some embodiments, the zone that comprises the material with maximum heat coefficient of expansion has maximum relative volume, and occupy the central area at carbide PCD interface, and the thermal coefficient of expansion that extends to each next adjacent volume of circumferential edge in the central area from the PCD platform reduces gradually.In this case, it is very large that the quantity in a plurality of zones becomes, and these regional thickness are near the microstructure yardstick of material, but the therefore continuously grade progressively of implementation structure, composition and character.

In this way, the PCD platform may most of or fully classification, and wherein the central area of PCD platform is away from circumferential Free Surface place, and by the Material Filling with maximum heat coefficient of expansion.

With reference to Fig. 5, the material in Section Eight territory 8 may on average have the intermediate heat coefficient of expansion between the 9th and the tenth zone 9,10 usually, and is configured such that from the material in material to the ten zones 10 in the 9th zone 9 in constituent and series classification in nature.This is favourable, because it can slow down any stress drastic change of not expecting from a zone to other zone.

Thereby by further considering Fig. 2 and selecting the material of specific region to make it have identical thermal coefficient of expansion, can realize more embodiments.Any two or any three or any four or All Ranges in second area 2, the 3rd zone 3, the 4th zone 4, the 5th zone 5 and the 6th zone 6 can be made by the material with identical thermal coefficient of expansion.In addition, can be so that any one the regional material in the material of first area 1 and second area 2, the 5 and the 6th zone 6, the 5th zone has identical thermal coefficient of expansion.Equally, second area 2, the 3rd zone 3, the 4th zone 4, the 5 and the 6th zone 6, the 5th zone can be by the material manufacturings with same coefficient of thermal expansion, but still less than the thermal coefficient of expansion of the material of first area 1, as shown in Figure 7.In Fig. 7, the combination in second area, the 3rd zone, the 4th zone, the 5th zone and the 6th zone is denoted as 12.

Although do not change significantly the axial tensile stress of the regional A2 of Fig. 1 according to the cutter of a rear embodiment manufacturing, but still the radially tensile stress of B1 and the circumference stress of A1 have been reduced, simultaneously importantly, make this latter two critical zone move away from Free Surface and enter the body of PCD platform.

Other embodiment can be realized by considering Fig. 2, for example, the first area 1 that comprises the material with maximum heat coefficient of expansion is occupied away from the Free Surface of PCD platform and the volume that is generally annular at carbide interface, as shown in Figure 8.The modification relevant with the arrangement of the relatively hot coefficient of expansion of material in second area 2 to the 6th zones 6 is applicatory.

Fig. 9 is schematic diagram, wherein the second area 2 of Fig. 8, the 3rd zone 3, the 4th zone 4, the 5 and the 6th zone 6, the 5th zone are by the material manufacturing with same coefficient of thermal expansion, be designated as now 11, it surrounds first area 1 annular, that made by the material with maximum heat coefficient of expansion.

In addition, thereby generate the new material zone with suitable character by the border of expanding between any zone, can obtain for design design, that have a plurality of zones shown in Fig. 7,8 and 9.Around the first area 1 of annular and the embodiment of several new regions of concentric arrangement as shown in figure 10.

About described any one or a plurality of embodiment, zone with material of the maximum heat coefficient of expansion may be divided into the zone of a more than separation, and the zone of all these separation can separate by the circumferential Free Surface of at least a material with less thermal coefficient of expansion with the PCD platform.These a plurality of volumes with identical maximum heat coefficient of expansion can be for example any 3 dimensional coil geometry, such as annulus, ellipsoid, cylinder, spheroid etc.Cumulative volume with material of the maximum heat coefficient of expansion can for example occupy 30% to 95% of PCD platform cumulative volume.

Figure 11 is for to have the embodiment that is distributed in four annular volume in the PCD platform.

Up to the present all embodiments of describing are axially symmetrical with respect to how much cutters of common cylinder of prior art, and relevant with the critical zone of crack initiation shown in Figure 1 and diffusion.Usually, comprise circumferential child partition selected, volume that be attended by different selected properties, different materials, no matter be axially symmetrical or asymmetric, all can be used to change residual stress distribution, and may advantageously affect crack initiation and diffusion.By this method, residual stress distribution may be from axial symmetry change for axially asymmetric, in order to reduce or eliminate the tensile stress of not expecting in the general polishing scratch position.

Also can imagine, although special PCD material is good especially in wearability and Rock Cutting aspect of performance, but it is not to be positioned at the marginate ideal material of cutter, because for volume on every side, desirable little of its thermal coefficient of expansion and/or modular ratio is so the residual stress in the volume of itself is less than desirable residual stress.In this case, can utilize any axisymmetric embodiment describing and illustrate by Fig. 2 to 12 or any other this type of modification can be used in abutting connection with and near this material volume, in order to advantageously change residual stress field in the border of this volume." near " in this article the meaning is to support the material volume adjacent with selected sector, it is forced favourable stress changes on selected sector.This can realize as cutting zone by introducing interruption and " embedding " material volume in axisymmetric embodiment.Promising change comprises the reduction of tension force, and the increase of pressure and maximum tensional stress are away from the movement of the Free Surface of PCD platform, and especially, these maximum tensional stresses separate by compression field and Free Surface.This section or sector with excellent abrasive resistance material can be inserted into the peripheral interruptions that creates as in Fig. 2 to 12 any embodiment of describing and illustrating.These sections or sector will be used as the Rock Cutting position and form subsequently the position of polishing scratch.Peripheral place arranges a more than this section or sector at the PCD platform, and its symmetrical or asymmetrically setting is to make things convenient for the repeatedly recycling of this type of cutter.

Cutter in the embodiment that polishing scratch is arranged of having described is carried out FEA to be analyzed.Conclusion is, can be because of the removal of the PCD at polishing scratch place and the change of essence occurs in the residual stress field.Reason is, and is smaller for the PCD cumulative volume at the volume of the removed material in typical polishing scratch place.By forming gradually the polishing scratch of typical sizes, have any specific embodiment the residual stress field characteristic axially, radially neither can significantly reduce in size with the hoop maximum, force, can the shift position yet.

Describe in more detail some embodiments according to the following examples now, the present invention should be interpreted as to be limited to embodiment described here.

Embodiment 1

Manufacturing is based on the PCD cutter of the embodiment of Fig. 2 a, 2b.Figure 13 is the schematic diagram of the particular design that adopts of these cutters.The thickness of final PCD platform is 2.2mm, and it is incorporated into length is that the weight ratio of 13.8mm, tungsten carbide is on 13% the hard metallic matrix of cobalt.The diameter of straight cylinder cutter is 16mm, and total length is 16mm, and has the plane boundary between PCD platform and carbide substrate.

With reference to Figure 13, use the known flow casting molding manufacturing technology of prior art to make the volume 1 to 6 of different PCD materials.Make base dish or the packing ring of six kinds of different diamond dusts with water-soluble binder.In every kind of situation, be used to form the dish of the solid among Figure 13 and the assembly of packing ring and be placed in the refractory metal vessels, and this refractory metal vessels is installed on the preburned tungsten carbide/cobalt hard metal cylinder.This assembly next will be to be enough to remove the temperature and time vacuum outgas of adhesive material in smelting furnace.Then, this assembly bears the pressure of about 1450 ℃ temperature and about 5.5GPa in high-tension apparatus.In these cases, the fusing of the cobalt binder of tungsten carbide hard metal also penetrates in the hole of diamond dust assembly, carries out diamond sintering.

After diamond sintering was finished, condition was reduced to room temperature and constant pressure.Under high temperature and high pressure, cutter material is in the thermoelasticity balance.After being quenched to indoor conditions, the nature difference between various PCD materials and the hard metal matrix has formed synthetic residual stress distribution in cutter PCD platform.

With reference to Figure 13, make as follows in six zones of different PCD materials.

The material of first area 1 by average grain diameter be about 6 microns, diamond dust manufacturing with 2 microns multimode distribution of sizes in 16 micrometer ranges.Known this diamond dust forms the PCD material under employed high-temperature and high-pressure conditions, the volume content of its cobalt is about 12%, has 4.5 * 10 ^-6/ ℃ thermal linear expansion coefficient and the elastic modelling quantity of 860GPa.This is the material of thermal coefficient of expansion maximum.

The material of second area 2 be by average grain diameter be about 12.5 microns, diamond dust manufacturing with 2 microns multimode distribution of sizes in 30 micrometer ranges.Known this diamond dust forms the PCD material under employed high-temperature and high-pressure conditions, the volume content of its cobalt is 10.2%, has 4.15 * 10 ^-6/ ℃ thermal linear expansion coefficient and the elastic modelling quantity of 980GPa.

The material in the 3rd zone 3 be by average grain diameter be about 5.7 microns, diamond dust manufacturing with 1 micron multimode distribution of sizes in 12 micrometer ranges.Known this diamond dust forms the PCD material under employed high-temperature and high-pressure conditions, the volume content of its cobalt is 10%, has 4.0 * 10 ^-6/ ℃ thermal linear expansion coefficient and the elastic modelling quantity of 1005GPa.

The material in the 4th zone 4 is to be about 25 microns, to be had a diamond dust manufacturing 4 microns multimode distribution of sizes in 45 micrometer ranges by average grain diameter.Known this diamond dust forms the PCD material under employed high-temperature and high-pressure conditions, the volume content of its cobalt is 7.7%, has 3.7 * 10 ^-6/ ℃ thermal linear expansion coefficient and the elastic modelling quantity of 1030GPa.

The material in the 5th zone 5 is to be about 33.5 microns, to be had a diamond dust manufacturing 4 microns multimode distribution of sizes in 75 micrometer ranges by average grain diameter.Known this diamond dust forms the PCD material under employed high-temperature and high-pressure conditions, the volume content of its cobalt is 7%, has 3.4 * 10 ^-6/ ℃ thermal linear expansion coefficient and the elastic modelling quantity of 1040GPa.This is the material of thermal coefficient of expansion minimum and has maximum diamond volume content: 93%.

The material in the 6th zone 6 is to be about 6.4 microns, to be had a diamond dust manufacturing 3 microns multimode distribution of sizes in 16 micrometer ranges by average grain diameter.Known this diamond dust forms the PCD material under employed high-temperature and high-pressure conditions, the volume content of its cobalt is 11.5%, has 4.25 * 10 ^-6/ ℃ thermal linear expansion coefficient, and the elastic modelling quantity of 925GPa.

Behind high-tension apparatus taking-up cutter, obtain its final size by grinding well known in the prior art and finishing method.The cutting tool sample is also got its cross section, in order to measure the volume of different PCD materials, and estimates that it is with respect to the volume of PCD platform cumulative volume.

It is estimated, account for about 75% of PCD platform cumulative volume by the material of the first area of the material manufacturing with maximum heat coefficient of expansion.

The material in the 6th zone 6 accounts for the about 3% of PCD platform cumulative volume, and it is from the center wire diameter to extending about 4mm, and the about 0.25mm of thickness, and the material of first area 1 is separated with the tungsten carbide hard metal matrix.

The material in the 3rd zone 3 accounts for the about 8% of PCD platform cumulative volume, and the material in itself and the 6th zone 6 is adjacent, radially extends to 4mm outside the peripheral Free Surface of platform, and thickness is about 0.25mm, and the material of first area 1 is separated with the tungsten carbide hard metal matrix.

The material in the 4th zone 4 accounts for the about 5% of PCD platform cumulative volume, and the material in itself and the 3rd zone 3 is adjacent, is positioned at the circumferential Free Surface place of PCD platform, and the material of the first area 1 circumferential Free Surface with the PCD platform is separated.

The material in the 5th zone 5 accounts for the about 6% of PCD platform cumulative volume, and the material in itself and the 4th zone 4 is adjacent, and thickness is about 0.25mm, and the material of the first area 1 top Free Surface with the PCD platform is separated.

The material of second area 2 accounts for about 3% of PCD platform cumulative volume, its thickness is about 0.25mm, and is adjacent with the material in the 5th zone 5, radially extends 4mm from the axis, it extends across the middle part of the top Free Surface of cutter, and the material of the first area 1 top Free Surface with cutter is separated.

Utilize finite element analysis (FEA) to the cutter modeling of the PCD material property of the synthetic measurement volumes size of having of manufacturing and expectation.This is a kind of numerical value stress analysis technique, and it can calculate the stress distribution on the cutter dimension.For purpose relatively, calculate the stress distribution of the facing tool that only has the platform of being made by a kind of material corresponding with the material in the 4th zone 4, and with making reference.

Figure 14 a, b, c are the stress distribution schematic diagrames that only uses a kind of facing tool of PCD material manufacturing.

Figure 14 a has shown axial tensile force and pressure field and maximum tension and pressure position.Chain-dotted line represents the border between tension field and the pressure field, and tension field has hacures.As seen, maximum axial tension force is positioned at the circumferential Free Surface place of PCD platform, above basal body interface tight.Maximum axial tension force is relevant with the critical zone A2 among Fig. 1.Except extending to PCD top Free Surface from basal body interface and by the axial tensile force field and the axial compression stress field that circumferentially Free Surface separates, most PCD platform also is in the axial tensile force.Maximum pressure is positioned at pressure field inside, above basal body interface is tight.

Figure 14 b has shown radial tension field and pressure field and maximum tension and pressure position.With the single radial tension of shadow representation field, the position of maximum radial tension force is in the top Free Surface of PCD platform in Figure 14 b.This maximum radial tension force is relevant with critical zone B1 among Fig. 1.Basal body interface place shown in maximum pressure is positioned at.

Figure 14 c has shown hoop tension field and pressure field and maximum tension and pressure position.The limited bulk that is in the drift angle place on every side in the tension force in figure shown in the shaded area, most of PCD platforms also bear circumferential pressure.Maximum loop to tension force at the Free Surface place and relevant with the A1 critical zone of Fig. 1.

Following table 1 has provided the comparative result of finite element analysis, and it represents the components of stress size of this embodiment and the comparison of facing tool as a reference.

Table 1

As can be seen from Table 1, the maximum axial tension force relevant with critical zone A2 among Fig. 1 has reduced by 32%.This maximum position is not compared with the maximum position shown in Figure 14 a and is changed, shown in A among Figure 13.

Similarly, the maximum radial tension force relevant with the critical zone B1 among Fig. 1 has reduced by 29%.Yet this peaked position is subjected to displacement and moves away from the Free Surface of PCD cutter, has occupied the position of material area 1 inside, shown in the R among Figure 13.

The maximum loop relevant with critical zone A1 among Fig. 1 reduced by 126% to tension force, and it has just become the minimum pressure position and be subjected to displacement and moved away from the Free Surface of PCD platform like this.This moment, it occupied the position of material area 1 inside, shown in H among Figure 13.Moreover the whole volume of PCD platform is under the circumferential pressure now, therefore without any hoop tension force.As seen, compare the planar materials cutter of institute's reference, the tension force of critical zone A2, B1 and A1 obviously reduces.In the situation of critical zone B1 and A1, they move away from the Free Surface of PCD platform, and separate with the top Free Surface by the material that is in radially with circumferential pressure.

Generally speaking, the finite element analysis of the cutter of the embodiment 1 that makes corresponding to the general embodiment of Fig. 2 a and b shows that the tensile stress among Fig. 1 in the critical zone of the preferential diffusion of crackle reduces and the increase of pressure aspect aspect tension force.In addition, some critical zone is shifted, so that they no longer are subjected to the restriction of the Free Surface of PCD platform.Like this, be expected to suppressedly maybe may be prevented to the trend of the Free Surface of cutter diffusion crackle.For the cutter of this general design, in boring is used, reduced the possibility of peeling off, and increased cutter life.

Embodiment 2

Manufacturing is based on the PCD cutter of the embodiment of Fig. 7.Figure 15 is the sketch of the employed particular design of these cutters.As among the embodiment 1, the thickness of final PCD platform is 2.2mm, and weight ratio is 13% cobalt hard metal matrix, and length is 13.8mm, is attached on the tungsten carbide.The diameter of straight cylinder cutter is 16mm, and whole length is 16mm, and has planar interface between PCD platform and carbide substrate.

In this embodiment, the PCD platform is only by the volume manufacturing of two kinds of different PCD materials.PCD material with maximum heat coefficient of expansion forms a dish, is designated as 1 in Figure 15, its basal body interface around volume and PCD platform by being designated as 12 the PCD material with relatively low thermel expansion coefficient among Figure 15, top surface and circumferentially Free Surface separate.

Manufacturing process and process described in use as the above-mentioned embodiment 1.

Yet in this case, employed temperature and pressure condition is respectively about 1470 ℃ and 5.7GPa.

With reference to Figure 15, make as follows in two zones of different PCD materials.

First area 1 be by average grain diameter be about 12.6 microns, diamond dust manufacturing with 2 microns multimode distribution of sizes in 16 micrometer ranges.Known this diamond dust forms the PCD material under employed high pressure and hot conditions, the volume content of its cobalt is about 9%, has 4.0 * 10 ^-6/ ℃ thermal linear expansion coefficient and the elastic modelling quantity of 1020GPa.This is the material of thermal coefficient of expansion maximum.

Be enclosed in second area 12 around the first area 1 among Figure 15 and be by average grain diameter be about 33 microns, diamond dust manufacturing with 6 microns multimode distribution of sizes in 75 micrometer ranges.Known this diamond dust forms the PCD material under employed high-temperature and high-pressure conditions, the volume content of its cobalt is about 6.5%, has 3.4 * 10 ^-6/ ℃ thermal linear expansion coefficient and the elastic modelling quantity of 1040GPa.

Behind high-tension apparatus taking-up cutter, obtain the last size of each cutter by grinding well known in the prior art and finishing method.The cutting tool sample is also got its cross section, in order to measure the volume of different PCD materials, and estimates that it is with respect to the volume of the cumulative volume of PCD platform.

It is estimated that account for the about 67% of PCD platform cumulative volume by the first area 1 of the material manufacturing with maximum heat coefficient of expansion, volume accounts for 33% on every side.First area 1 and the about 0.25mm in matrix interval are with the about 0.4mm in Free Surface interval, top of platform, with the about 0.4mm in circumferential Free Surface interval of platform.

Utilize finite element analysis (FEA) to the cutter modeling of the synthetic measurement volumes size of having of manufacturing and expectation PCD material property.This technology can be calculated the stress distribution on the tool dimension.For purpose relatively, only have by with Figure 15 in be designated as 12 around the stress distribution of facing tool of platform of material manufacturing corresponding to the material of volume calculated and with making reference.Below table 2 provided the comparative result of finite element analysis, its expression maximum principal stress and principal stress in cylindrical-coordinate system easily axially, radially, circumferential component.

As can be seen from Table 2, maximum axial and radially tensile stress reduce respectively 9% and 6%.And maximum circumferential component tensile stress increases about 12%.

The position that should also be noted that the maximum axial force that is designated as A among Figure 15 does not change, and the size of the axial compressive force field of reinforcement is-424MPa that it is close to first area 1 and forms, and the circumferential Free Surface of this volume with the PCD platform separated.

Table 2

Notice that the position of maximum radial and hoop tensile stress changes.Maximum radial and hoop tension force are shifted, and occupy now the position of inside, 1 border, first area, are denoted as R and H in Figure 15, and separate by substantial radial and the circumferential pressure Free Surface with the PCD platform thus.The increase of quantity when maximum loop has been offset the crackle diffusion to the displacement of tensile stress.Although the crackle of diffusion can be attracted by these tensile stress, lead to material in the compression with suppressing crackle, tension zone and Free Surface are separated.Crackle just can not arrive easily Free Surface and cause spallation like this.

FEA result shows, in the cutter of making such as the embodiment of Fig. 7, the axial tensile stress in the A2 zone among its Fig. 1 probably reduces, and simultaneously adjacent axial compressive force strengthens.The radially tensile stress in B1 zone reduces and is mobile, thereby is no longer limited by the top Free Surface of PCD platform, and separates by radial pressure band and top Free Surface.In addition, in fact do not increased on the contrary although the maximum loop relevant with critical zone A1 reduces to tensile stress, it also moves away from the Free Surface of PCD platform.This maximum loop has occupied the tight adjacent position of 1 inside, first area now to tension force, and is surrounded by circumferential pressure fully, and this circumferential pressure separates maximum loop to all Free Surfaces and the basal body interface of tension force with the PCD platform.

Comprehensive these results can expect, and in boring was used, the diffusion process of the crackle of these cutter polishing scratch back was with suppressed and can be across pressure barrier, and this pressure barrier separates crackle and PCD platform Free Surface.This crackle can be retained in the PCD playscript with stage directions body, and therefore adopts the cutter of this design can suppress spallation and premature failure.

Embodiment 3

The PCD cutter of making according to Figure 16 a is based on a kind of particular design of the embodiment of Fig. 5, and its PCD platform is to use three kinds of different PCD materials to make.Use have the maximum heat coefficient of expansion and the PCD material of high tenor make dish, this dish is designated as 13 in Figure 16 a, it is positioned at the basal body interface center and is symmetrical arranged around the center cutter axis.Use the material volume of the PCD material manufacturing of minimum coefficient of thermal expansion and lowest metal content to be designated as 15 in Figure 16 a, it extends across all Free Surfaces of PCD platform, that is: peripheral surface and top surface.Use the intermediate heat coefficient of expansion and intermetallic metal content (with respect to as be designated as 14

zone

13 and 15 material among Figure 16 a) the PCD material of material manufacturing occupied volume for

separation region

13 and 15.

The thickness of final PCD platform is 2.2mm, and weight ratio is 13% cobalt hard metal matrix, and its length is 13.8mm, is attached on the tungsten carbide.The diameter of straight cylinder cutter is 16mm and has planar interface between PCD platform and carbide substrate.

As

embodiment

1 and 2, use the stream forming technique that prolongs well known in the prior art, form alleged base dish and the packing ring of the diamond dust of three kinds of suitable selections of being combined with water-soluble organic bond.By these dishes of assembling and packing ring in refractory metal vessels, produce the solid among Figure 16 a.Then, with the tungsten carbide cylinder, contain 13% cobalt hard metal cylinder and insert in the refractory metal vessels to form and to provide matrix.

Then, these assemblies carry out vacuum outgas with the temperature and time that is enough to remove adhesive material in stove.Then, assembly bears the pressure of about 1460 ℃ temperature and about 5.6GPa in high-tension apparatus, and this is known in the prior art.Under these conditions, the fusing of the cobalt binder of tungsten carbide hard metal adhesive also penetrates in the hole of diamond dust assembly, carries out diamond sintering.After diamond sintering was thoroughly finished, condition was reduced to room temperature and constant pressure.Under high pressure and high temperature, cutter material is in the thermoelasticity balance.After being quenched to indoor conditions, the nature difference between the various PCD materials with and and hard metal matrix between nature difference in cutter PCD platform, formed synthetic stress distribution.

With reference to figure 16a, the Three regions of different PCD materials is made as follows.

Among Figure 16 a zone 13 PCD material by average grain diameter be about 5.7 microns, diamond dust manufacturing with 1 micron multimode distribution of sizes in 12 micrometer ranges.Known this diamond dust forms the PCD material under employed high pressure and hot conditions, the volume content of its cobalt is about 10%, has 4.1 * 10 ^-6/ ℃ thermal linear expansion coefficient and the elastic modelling quantity of 1006GPa.This is the material of the maximum heat coefficient of expansion and tenor.

Perimeter 15 among Figure 16 a be by average grain diameter be about 25 microns, diamond dust manufacturing with 4 microns multimode distribution of sizes in 45 micrometer ranges.Known this diamond dust forms the PCD material under employed high pressure and hot conditions, the volume content of its cobalt is about 7.4%, has 3.6 * 10 ^-6/ ℃ thermal linear expansion coefficient and the elastic modelling quantity of 1030GPa.

Zone line 14 among Figure 16 a, by average grain diameter be about 12.6 microns, diamond dust manufacturing with 2 microns multimode distribution of sizes in 30 micrometer ranges.Known this diamond dust forms the PCD material under employed high pressure and hot conditions, the volume content of its cobalt is about 8.9%, has 3.9 * 10 ^-6/ ℃ thermal linear expansion coefficient and the elastic modelling quantity of 1020GPa.

Behind high-tension apparatus taking-up cutter, obtain its final size by grinding well known in the prior art and finishing method.The cutting tool sample is also got its cross section, in order to measure the volume of different PCD materials, and estimates the volume of its relative PCD platform cumulative volume.The border of zone between 13 and 14 is positioned at axially away from the about 1.0mm of basal body interface place, and apart from the circumferential about 0.5mm of Free Surface.Border between the

zone

15 and 14 is positioned at the about 0.6mm of the top Free Surface place apart from the PCD platform, and apart from the circumferential about 0.25mm of Free Surface.

It is estimated that zone 13 accounts for about 38% of PCD platform cumulative volume.It is estimated that

zone

14 and 15 accounts for respectively about 23% and 47% of PCD platform cumulative volume.

Utilize finite element method (FEA) to the cutter modeling of the PCD material property of the synthetic measurement volumes size of having of manufacturing and expectation.This technology allows to calculate the stress distribution on the cutter dimension.For purpose relatively, calculate only have by with Figure 16 a in be designated as a kind of material manufacturing corresponding to the material of 15 peripheral region platform facing tool stress distribution and with making reference.Figure 14 a, b, c shown position and the scope of the tensile stress of this reference planes cutter and compression be broken down into respectively axially, radially with the hoop direction.Similarly, Figure 16 a, b, c show the decomposition stress of the current embodiment that calculates.The tensile stress shadow representation, the border of tension force and pressure represents with chain-dotted line.The position of maximum tension and pressure also is marked in the drawings.Maximum axial tension force with reference to cutter among Figure 14 a is relevant with the critical zone A2 among Fig. 1, and the maximum radial tension force among Figure 14 b is relevant with the critical zone B1 among Fig. 1, and maximum loop is relevant with the critical zone A1 among Fig. 1 to tension force among Figure 14 c.

Table 3 has provided the FEA comparative result, this as a result the maximum stress of the cutter of the embodiment 3 among presentation graphs 16a, b and the c in cylindrical-coordinate system easily axially, radially, the comparison of circumferential component and facing tool as a reference (Figure 14 a, b, c).

Table 3

Table 3 knows that critical zone A2, the B1 of the cutter that has shown embodiment 3 and the stress among the A1 have significantly reduced aspect tension force.And the circumference stress relevant with critical zone A1 is converted into obvious pressure, and this causes whole PCD platform to be in the circumferential pressure.

Axial stress among comparison diagram 16a and Figure 14 a distributes and can find out, circumferentially the tension field area of Free Surface and size obviously reduce, and be as shown in table 3.By these results, can expect to reduce the trend of crack initiation, and the scope of any crackle that may germinate will be limited.

Radial stress among the comparison diagram 16b distribute and Figure 14 b in reference distinguish, can find out that maximum tension is away from the Free Surface of PCD platform and be displaced in the intermediate materials zone 14.This position just is in the bulk volume of PCD platform, and this position separates by radial compressive stress field and Free Surface at this moment.Therefore, can think that the critical zone B1 of Fig. 1 is removed, so that it is limited by the Free Surface of PCD platform no longer, and this moment, this critical zone separated by pressure barrier and Free Surface.The variation of this position, critical zone all is expected to suppress the diffusion of crackle and stops it to be diffused into the top Free Surface of cutter together with the obvious minimizing of radial tension.

Comparison diagram 16c and distribute with reference to the circumference stress among the figure 14c can find out that tension field is completely eliminated, so that whole PCD platform all is in the circumferential pressure.And, being replaced by minimum pressure now with the maximum tension position that critical zone A1 is relevant among Fig. 1, this minimum pressure has been moved so that it is limited by the Free Surface of PCD platform no longer.This minimum pressure is arranged in the material of Figure 14 at this moment.

Can expect all these effects of combination, the diffusion of any crackle that forms so that Rock Cutting is associated with polishing scratch during using is suppressed, and prevents Free Surface that it extends to cutter and the spallation of PCD platform.

Embodiment 4

Make the PCD cutter according to Figure 17, single 60 ° of sections of PCD material form in the top periphery edge of cutter thus, and all the other 300 ° of part adjacency of its design by embodiment 3 and cutter and near.Figure 17 is this newly-designed three dimensional representation, and it is with the section that cuts, and wherein, 60 ° of peripheral sections that are designated as 15 external volume among Figure 16 a, b, the c are designated as 16 material substitution among Figure 17.As from determining the Rock Cutting test, known this PCD material has good wearability.300 ° of remainders of cutter use Figure 16 design and near 60 ° of sections.

As among the

embodiment

1,2 and 3, final PCD platform thickness is 2.2mm, and weight ratio is 13% cobalt hard metal matrix, and its length is 13.8mm, is attached on the tungsten carbide.The diameter of straight cylinder cutter is 16mm, and it has planar interface between PCD platform and carbide substrate.

As among the

embodiment

1,2 and 3, use flow casting molding technology well known in the prior art, select four kinds of suitable diamond dusts and be combined to make alleged base dish, packing ring and sector with soluble organic adhesive.Make solid among Figure 17 by assembling these dishes, packing ring and sector in refractory metal vessels.Then, tungsten carbide cylinder, 13% cobalt hard metal cylinder are inserted in the refractory metal vessels to form and to provide matrix.

Then these assemblies are put in the stove to be enough to remove the temperature and time vacuum outgas of adhesive material, and and then, assembly bears pressure and the about 1460 ℃ temperature of about 5.6GPa in high-tension apparatus, and this is known in the prior art.

With reference to Figure 17, use with embodiment 3 in and be designated as identical powder in 13,14,15 the zone in Figure 16 and 17, consist of 300 ° of parts near 60 ° of sections by the Three regions of different PCD materials.

Be designated as among Figure 17 60 ° of section materials of 16 by average grain diameter be about 13.0 microns, diamond dust manufacturing with 2 microns multimode distribution of sizes in 30 micrometer ranges.Known this diamond dust forms the PCD material under employed high pressure and hot conditions, the volume content of its cobalt is about 8.8%, has 3.95 * 10 ^-6/ ℃ thermal linear expansion coefficient and the elastic modelling quantity of 1025GPa.In the Rock Cutting test, confirm that this special material has extraordinary low wearing character.

Behind high-tension apparatus taking-up cutter, obtain the final size of each cutter by grinding well known in the prior art and finishing method.The cutting tool sample is also got its cross section, in order to measure the volume size of different PCD materials, and estimates the volume of its relative PCD platform cumulative volume.Border between the

zone

13 and 14 is positioned at axially away from the about 1.0mm of basal body interface place, apart from the circumferential about 0.5mm of Free Surface.Border between the

zone

15 and 14 is positioned at the about 0.6mm of the top Free Surface place away from the PCD platform, apart from the circumferential about 0.25mm of Free Surface.60 ° of sections radially extend about 2mm from circumferential Free Surface, and its thickness at Free Surface place, the top of PCD platform is approximately 0.6mm, and the thickness at circumferential Free Surface place is approximately 0.25mm.

Zone

13,14 and 15 accounts for respectively about 38%, 23% and 44% of PCD platform cumulative volume.60 ° of sections, namely about 3% of PCD platform cumulative volume is estimated to account in zone 16.

Use finite element analysis (FEA) to the cutter modeling of the synthetic estimation volume of having of manufacturing and size and expectation PCD material property.As a reference, consider the facing tool among Figure 14 a, b, the c, its have with Figure 17 in be designated as 60 ° of material properties that section is identical of 16.The intrinsic propesties of the stress distribution of this facing tool is as shown in Figure 14 a, b, c.For reference and embodiment design, selected boundary condition and trellis-type for calculating is constant, can carry out the comparison of maximum stress size like this.

Table 4 provides the comparative result of finite element analysis, wherein, the maximum stress value in 60 ° of sections that calculate is compared with the corresponding maximum stress value of plane with reference to cutter, and this PCD material and material 16 among Figure 17 with reference to cutter is identical.

Table 4

The maximum axial tensile stress is positioned at the circumferential Free Surface place of PCD platform, just in time above the basal body interface (as the plane with reference to cutter in), and relevant with the critical zone A2 among Fig. 1; But with respect to the section peripheral boundaries that is represented by A among Figure 17, this maximum axial tensile stress is positioned at 30 ° of positions.This maximum axial tension force is compared with reference to cutter with the plane and has been reduced about 47%.

Maximum radial tensile stress in this section is arranged in the top Free Surface (such as the plane with reference to the cutter) of PCD platform, and relevant with critical zone B1 among Fig. 1, is represented by R in Figure 17.This maximum radial tension force is compared with reference to cutter with the plane and has been reduced about 66%.

Maximum loop in this section to tensile stress be arranged in the PCD platform the top Free Surface (as on the plane with reference to the cutter), and relevant with critical zone A1 among Fig. 1, in Figure 17, represented by H.This maximum loop is compared with reference to cutter with the plane to tension force and has been reduced about 52%.Therefore, be used for adjacency and can cause the obvious minimizing of tensile stress in the section material near the Tool Design PCD material section, embodiment 3.Also find, also in the adjacent material of embodiment 4, found the favourable stress distribution among the embodiment 3, but the tensile stress of 60 ° of section boundaries of next-door neighbour there are some increases among the embodiment 4.

Expectation be, and compared by the facing tool of same material manufacturing, the trend of Crack Extension can reduce in the section material, and spallation trend also reduces thus, so that the excellent abrasive resistance of section material can be used in during Rock Cutting uses.And the adjacency in the design of embodiment 3 and also may suppress crackle diffusion and suppress the Free Surface that crackle arrives the PCD platform near the very favorable stress distribution in the material, as described in Example 3.This also helps to reduce the generation of spallation.

These results show, based on the Tool Design of some embodiment with favourable residual stress distribution can be used for making the PCD material each section adjacency and near, and with respect to the situation of independent use section material, this can effectively reduce the tensile stress in these sections.

What expect is when using more than a section, similar result to occur.

The geometry of the interface boundary between the carbide substrate that can revise the PCD platform and be bonded thereto, thereby the residual stress field in the change PCD platform.These interfaces that are modified are called as non-planar interface, and it may be to the most influential near the general stress distribution in the position at interface.Substantial variation does not occur because taking the non-planar interface design in the general features of the critical zone that Fig. 1 described and indicated, but can use with some embodiment is collaborative.Figure 12 has provided an embodiment, and it has 1 to the 6th zone 6, first area shown in Fig. 2 a and 2b, but has non-planar interface, and its carbide substrate interface is convex substantially about the top surface of PCD platform.

In addition, by comprising such as inclined-plane etc., can implement the modification to the geometry of start edge, in order to reduce early stage chip event.This practice can be worked in coordination with arbitrary or all embodiments and be used.

In addition, remove whole PCD material metal compositions or its part removed to the performance that can be used to improve the PCD cutter apart from the processing at the selected depth place of Free Surface.The exemplary depth that adopts drops between 50 and 500 microns.This improvement it is believed that the improvement of the material heat endurance that mainly is to process depth.Yet the shortcoming relevant with this treatment process is the increase of the tensile stress in the PCD material adjacent with processing layer, and this can cause crackle diffusion of not expecting.Each embodiment can be by offsetting tensile stress by the compression of placing the preexist that selected material causes, thereby the method for slowing down this shortcoming is provided.Therefore, can work in coordination with this processing method of use with one or more embodiments.

And, thereby some heat treatment partly annealing residual stress reduce its size.Typical this processing is after high-tension apparatus is withdrawn, and under the temperature between 550 ℃ and 750 ℃, heats in a vacuum the PCD cutter and reaches a few hours.This processing can advantageously change residual stress distribution, but only is limited extent.Such heat treatment can be applied to each embodiment.

Although the different application of previously described superhard structure, manufacture method and this structure and method comprises numerous characteristics, these features should not be construed as limiting the scope of the invention, but only as the explanation that some embodiments are provided.Similarly, can under the prerequisite that does not depart from the scope of the present invention, design other embodiment.For example, comprise superhard material with other materials and be set to have by making with material member and technology of preparing from the structure in district's band of described material different material manufacturing on performance and composition, block or zone, this technology of preparing is for such as any combination of prolonging stream moulding, injection-molded, powder extruding, ink jet printing, electrophoretic deposition etc. and these methods, all these technology all are suitable for being used to the superhard material powder, such as diamond and cubic boron nitride.In addition, although embodiment described here with particular reference to polycrystalline diamond abrasive compact, also can use other superhard material.In addition, by in appropriate area, placing other superhard material (usually comprising diamond), can use these materials to change the intrinsic stress distribution of polycrystalline material.

Embodiment 5

The embodiment of Fig. 7 has two kinds of different PCD materials, and it is made for test purpose.Figure 15 is the schematic diagram of the particular design that adopts of the modification for cutter.For this situation, the PCD material with maximum heat coefficient of expansion occupies and is designated as 1 volume among Figure 15, and the material with thermal coefficient of expansion of less occupies and is designated as 12 volume among Figure 15.The PCD material that occupies volume 1 in Figure 15 is about 6.4 microns and bortz powder manufacturing with 2 microns multimode distribution of sizes in 16 micrometer ranges by average grain diameter.Known this diamond dust forms the PCD material under employed high pressure and hot conditions, its cobalt volume content is about 11.5%, has 4.4 * 10 ^-6/ ℃ thermal linear expansion coefficient and the elastic modelling quantity of 930GPa.

The material of volume 12 is about 12.6 microns and diamond dust manufacturing with 1.5 microns multimode distribution of sizes in 16 micrometer ranges by average grain diameter among Figure 15.Known this diamond dust forms the PCD material under employed high pressure and hot conditions, its cobalt volume content is about 8.9%, has 4.0 * 10 ^-6/ ℃ thermal linear expansion coefficient and the elastic modelling quantity of 1020GPa.

As among the embodiment 1, final PCD platform thickness is 2.2mm, and weight ratio is 13% cobalt hard metal matrix, and its length is 13.8mm, is attached on the tungsten carbide.The diameter of straight cylinder cutter is 16mm, and total length is 16mm, and has planar interface between PCD platform and carbide substrate.

6.8GPa and the sintering condition of 1450 ℃ high pressure-temperature was kept 10 minutes.Then, use laboratory rock drill analogue means test sample cutter.Exerted pressure to the granite rock sample of rotation in a part of top periphery edge of cutter, cause continuous groove at rock sample like this, cause that by shear action host rock stone breaks.Continue test until the polishing scratch that produces on the cutter has just arrived the interface of tungsten carbide regions and PCD platform.There are not obvious fragment or spallation to occur.Thereby the cross section of radially getting the wearing and tearing sample runs through polishing scratch, and this cross section is polished and prepare to carry out microexamination.Figure 18 is the optical microscopy map of 20 times of amplifications, wherein can clearly see, the PCD material among Figure 15 in the central area of volume 1 approximately is that 1.5mm is thick.This material is approximately the PCD material with less thermal coefficient of expansion (such as the volume 12 among Figure 15) of 0.3mm by thickness and separates with basal body interface.

PCD material in the central area is by such as the thick material with less thermal coefficient of expansion of the 0.4mm of volume among Figure 15 12 and separate with the top Free Surface of PCD platform.Polishing scratch 17 extends to the interface of PCD and tungsten carbide matrix always, and the material of volume 1 just exposes.As seen, the leading crackle that accounts for that extends from polishing scratch mainly spreads the center P CD of volume 1, cutter volume, is acute angle away from the top Free Surface direction of PCD layer, and towards the interface of PCD and tungsten carbide matrix.Therefore this crackle can not cause spallation, and a large amount of PCD material blocks breaks away from from the top Free Surface of PCD platform thus.The residual stress distribution that shows, provide among the embodiment 1 of crackle away from this guiding of the Free Surface of PCD platform and this general embodiment is consistent, and is the feature of some embodiments.

Embodiment 6

Make the PCD cutter according to the embodiment of Fig. 2 a, thus, be designated as 2,4 with 5 volume by identical PCD material manufacturing.Figure 19 has shown the volume that is designated as 19 this combination.Volume 1 among Fig. 2 a, 3 is comprised of different PCD materials with 6, is designated as 20 and large thermal linear expansion coefficient and the tenor of material with specific volume 19 in Figure 19.Volume 20 among Figure 19 substantially specific volume 19 is thick, and volume 20 separates volume 19 and tungsten carbide matrix, and only extends to the circumferential Free Surface at the PCD platform, the interface of matrix, the localized positions of the tight top of PCD platform.Volume 19 extends across the top Free Surface of PCD platform and most of circumferentially Free Surface of PCD.

The material of the volume 19 among Figure 19 is about 12.6 microns and have diamond dust manufacturing 1.5 microns multimode distribution of sizes in 16 micrometer ranges by average grain diameter.Known this diamond dust forms the PCD material under employed high pressure and hot conditions, its cobalt volume content is about 8.9%, has 4.0 * 10 ^-6/ ℃ thermal linear expansion coefficient and the elastic modelling quantity of 1020GPa.

The PCD material that occupies the volume 20 among Figure 19 is approximately 6.4 microns and have diamond dust manufacturing 2 microns multimode distribution of sizes in 16 micrometer ranges by particle mean size.Known this diamond dust forms the PCD material under employed high pressure and hot conditions, its cobalt volume content is about 11.5%, has 4.4 * 10 ^-6/ ℃ thermal linear expansion coefficient and the elastic modelling quantity of 930GPa.

The condition of the size of PCD platform, tungsten carbide matrix, the overall dimensions of cutter and shape and PCD material sintering is according to embodiment 5.

Figure 20 is half cross section optical microscopy map through the cutter of overtesting and concentrated wear, and it has shown and is designated as 19 and 20 two kinds of PCD materials and worn-out surface 21.The ultimate position of polishing scratch also is denoted as 21 in Figure 19.As seen, be denoted as 22 the leading crackle that accounts for and extend from polishing scratch, and be drawn towards the interface of PCD platform and matrix in Figure 20, therefore be deflected the Free Surface away from the PCD platform, therefore, these crackles can not cause spallation.Be designated as the position that 23 crackle trends towards at first being diffused into the border that just in time is positioned at material 20, by the indicated maximum loop of the finite element analysis of this embodiment to occupying with tensile stress radially.These crackles at first are directed away from the top Free Surface of PCD platform in the mode of expectation, but as if when polishing scratch extended across border between

material

19 and 20, this crackle was swerved.

This is another embodiment that produces the fracture characteristics of required and expectation by the residual stress distribution (it is the feature of some embodiments) in the change PCD platform.

Embodiment 7

According to the design of the embodiment of embodiment 6 and make the PCD cutter, thus, the material with middle thermal linear expansion coefficient and tenor occupies and is designated as 19 volume in Figure 21 and 22.This volume makes and is designated as 24, that have less thermal linear expansion coefficient and tenor, as to extend to PCD platform top Free Surface material and is designated as 20, that have the maximum heat coefficient of expansion and tenor, as to extend to PCD platform and the interface of tungsten carbide matrix PCD material separates in Figure 21 and 22 in Figure 21 and 22.Material in the volume 24 among Figure 21 is approximately 20 microns and have the diamond dust manufacturing of the multimode size issue in 4 microns to 45 microns scope by average grain diameter.Known this diamond dust forms the PCD material under employed high pressure and hot conditions, the volume content of its cobalt is about 7%, has 3.5 * 10 ^-6/ ℃ thermal linear expansion coefficient and the elastic modelling quantity of 1040GPa.

The material of volume 19 is approximately 12.6 microns and have in the diamond dust manufacturing from 1.5 microns multimode distribution of sizes in 16 micrometer ranges by particle mean size among Figure 21.Known this diamond dust forms the PCD material under employed high pressure and hot conditions, the volume content of its cobalt is about 8.9%, has 4.0 * 10 ^-6/ ℃ thermal linear expansion coefficient and the elastic modelling quantity of 1020GPa.

The PCD material that occupies volume 20 among Figure 21 is approximately 6.4 microns and have in the diamond dust manufacturing from 2 microns multimode distribution of sizes in 16 micrometer ranges by average grain diameter.Known this diamond dust forms the PCD material under employed high pressure and hot conditions, the volume content of its cobalt is about 11.5%, has 4.4 * 10 ^-6/ ℃ thermal linear expansion coefficient and the elastic modelling quantity of 930GPa.

The condition of the size of PCD platform and tungsten carbide matrix, the overall dimensions of cutter and shape and PCD material sintering is according to

embodiment

5 and 6.

Figure 22 is the part cross section optical microscopy map through the cutter of laboratory simulation rock drilling experiment rear section wearing and tearing.Be designated as the position on 25 polishing scratch extends to PCD platform and tungsten carbide matrix from the top Free Surface of PCD platform the circumferential Free Surface of near interface, its worn out quilting material 24 and concentrated wear material 19.Clearly visible, account for leading 26 the crackle of being designated as from the extending than lower part of polishing scratch, and the interface between PCD platform and tungsten carbide matrix and guided downward.Therefore the unlikely top Free Surface that runs through the PCD platform of these crackles will can not promote spallation.

This is the another kind of embodiment of the advantageous feature of some embodiments, and thus, because the change of residual stress distribution in the PCD platform that the adjacent layout of the PCD material of selecting is especially brought, crackle is directed away from the Free Surface of cutter.

Claims

1. superhard structure, it comprises:

The polycrystalline superhard material body, it comprises:

The first area; And

Wherein, the thermal coefficient of expansion that forms one or more materials of first area and second area has difference, and first area and second area are configured such that the described difference between the thermal coefficient of expansion causes compression in the second area adjacent with described exposed surface; And wherein, first area or other zone have the maximum heat coefficient of expansion of polycrystalline body, and described first area or other zone are by the second area that formed by one or more materials with less thermal coefficient of expansion or one or more other zone and separate with the peripheral Free Surface of polycrystalline superhard material body, and wherein each zone comprises a plurality of polycrystalline superhard material crystal grain.

2. superhard structure according to claim 1, wherein, first area and second area have one or more other difference in physical property.

3. superhard structure according to claim 2, wherein, the one or more other difference on the physical property comprises the difference of the elastic modelling quantity of one or more materials that form the first and second zones.

4. according to each described superhard structure in the aforementioned claim, wherein, the polycrystalline superhard material body comprises polycrystalline diamond abrasive compact.

5. according to each described superhard structure in the aforementioned claim, also comprise the matrix that combines with the surface of polycrystalline material body along the interface.

6. superhard structure according to claim 5, wherein, described matrix is formed by carbide material.

7. according to claim 5 or 6 described superhard structures, also comprise the 3rd zone, the 4th zone, the 5th zone and the 6th zone, six zones, first area to the are axisymmetric, second area to the six zones are adjacent with the first area, and each zone in second area to the six zones has the thermal coefficient of expansion less than the first area; Wherein:

A) first area is arranged between second area and the matrix;

B) the 3rd zone is adjacent with the first area and at matrix and polycrystalline material body at the interface; The 3rd zone is positioned at and forms the part of the peripheral Free Surface of polycrystalline material body, and the 3rd zone is between first area and matrix;

C) the 4th zone is adjacent with the 3rd zone, and is positioned at the peripheral Free Surface place of polycrystalline superhard material;

D) the 5th zone is adjacent with second area with the 4th zone, and second area and the 4th zone are separated;

E) the 6th zone is adjacent with the first area, and first area and matrix are separated.

8. superhard structure according to claim 7, wherein, each zone in second area to the six zones has the material manufacturing of different heat expansion coefficient by one or more.

9. superhard structure according to claim 7, wherein, the 6th zone is formed by the material that has the maximum heat coefficient of expansion in the superhard structure.

10. superhard structure according to claim 9 wherein, forms first area, second area, the 3rd zone, the 4th zone and has different thermal coefficient of expansions with the material in the 5th zone.

11. superhard structure according to claim 7, wherein, the first area is formed by identical material with the 6th zone and has the maximum heat coefficient of expansion, and the material that forms first area and the 6th zone has than the large thermal coefficient of expansion of one or more materials that forms second area, the 3rd zone, the 4th zone and the 5th zone.

12. superhard structure according to claim 7, wherein, second area, the 3rd zone, the 4th zone and the 5th zone are formed by the material that one or more have different heat expansion coefficient.

13. each described superhard structure in 12 according to claim 5, wherein, the first area is formed by the material with maximum heat coefficient of expansion in the superhard structural material; The first area roughly is symmetrically located at polycrystalline material body and matrix at the interface about the axis of superhard structure, and separates by the Free Surface of second area with superhard material; Second area is formed by the material that has minimum coefficient of thermal expansion in the superhard structure.

14. superhard structure according to claim 13, wherein, the first area is subdivided into a plurality of independent volumes, and all volumes separate by the peripheral Free Surface of at least a material with less thermal coefficient of expansion with superhard structure.

15. superhard structure according to claim 14, wherein, one or more independent volumes are formed by the material that has the maximum heat coefficient of expansion in the superhard structure, and are annular.

16. according to each described superhard structure in the aforementioned claim, also be included in the three volumes between first area and the second area, three volumes is formed by the material that thermal coefficient of expansion is different from the thermal coefficient of expansion of the material that forms second area.

17. superhard structure according to claim 16, wherein, the material that three volumes is had in the thermal coefficient of expansion of the material that forms second area and superhard structure by thermal coefficient of expansion between the thermal coefficient of expansion in zone of maximum expansion coefficient material forms.

18. superhard structure according to claim 17, wherein, the one or more annular volume that formed by the material with maximum heat coefficient of expansion are segmented into has one or more interruptions.

19. according to each described superhard structure in the aforementioned claim, also comprise one or more material segments that are attached on a part of peripheral free edge, the polycrystalline material body in abutting connection with and near described peripheral free edge.

20. according to each described superhard structure in the aforementioned claim, wherein, the volume in the zone that is formed by the material with maximum heat coefficient of expansion occupy the whole volumes of polycrystalline material body about 30% to 95%.

21. according to each described superhard structure in the aforementioned claim, wherein, the thermal coefficient of expansion of material with maximum heat coefficient of expansion is different from the thermal coefficient of expansion of the material of adjacent area, and difference is about at least 0.3 * 10 ^-6/ ℃.

22. superhard structure according to claim 21, wherein, the polycrystalline material body is polycrystalline diamond abrasive compact, and is to be formed by the polycrystalline diamond abrasive compact that has maximum metal content for one or more polycrystalline diamond abrasive compacts in other zone by the zone that the material with maximum heat coefficient of expansion forms.

23. superhard structure according to claim 22, wherein, the volume ratio of the tenor in the polycrystalline diamond abrasive compact in each volume approximately is 10% or still less.

24. according to claim 22 or 23 described superhard structures, wherein, the difference of tenor is about 1.0% volume ratio at least between the zone.

25. according to each described superhard structure in the aforementioned claim, wherein, the polycrystalline material body comprises metal ingredient, described metal ingredient is transition metal alloy.

26. each described superhard structure in 24 according to claim 1, wherein, the polycrystalline material body comprises metal ingredient, and described metal ingredient is cobalt alloy.

27. according to each described superhard structure in the aforementioned claim, wherein, the polycrystalline material body comprises metal ingredient, wherein said metal ingredient is to have less than about 4 * 10 ^-6/ ℃ the alloy of thermal coefficient of expansion.

28. according to each described superhard structure in the aforementioned claim, wherein, the polycrystalline material body comprises metal ingredient, described metal ingredient comprises the second-phase material that changes the polycrystalline material thermal coefficient of expansion.

29. superhard structure according to claim 28, wherein, the second-phase material comprises metal carbides.

30. superhard structure according to claim 29, wherein, described metal carbides comprise tungsten carbide or carborundum.

31. superhard structure according to claim 28, wherein, described second-phase comprises oxide ceramics.

32. superhard structure according to claim 31, wherein, described oxide ceramics comprises aluminium oxide, Al ₂O ₃, zirconia, ZrO ₂In one or more.

33. according to each described superhard structure in the aforementioned claim, wherein, one or more zones are formed by the diamond that comprises composite.

34. superhard structure according to claim 33, wherein, described composite comprises the Diamond Ceramics composite.

35. superhard structure according to claim 1, wherein, the polycrystalline material body comprises the zone more than three that is formed by the material with different thermal coefficient of expansions, and wherein, border between the described zone is parallel substantially, and described zone has identical geometry.

36. according to each described superhard structure in the aforementioned claim, wherein, thermal coefficient of expansion changes at the adjacent area of polycrystalline material body in mode progressively.

37. superhard structure according to claim 5, wherein, the interface between polycrystalline material body and the matrix is nonplanar.

38. superhard structure according to claim 5, wherein, the interface between polycrystalline material body and the matrix is convex substantially.

39. according to each described superhard structure in the aforementioned claim, wherein, the polycrystalline material body has the peripheral edge of chamfering.

40. according to each described superhard structure in the aforementioned claim, wherein, the part of polycrystalline material body or whole Free Surface comprise layer, the tenor in the described layer is partially or completely removed.

41. according to each described superhard structure in the aforementioned claim, wherein, the part of polycrystalline material body or whole Free Surface comprise layer, and the tenor in the described layer has been completely removed or has been partially removed to the degree of depth between 50 microns and 500 microns.

42. according to each described superhard structure in the aforementioned claim, wherein, superhard structure is eliminated heat treatment through the stress in 550 to 750 ℃ of temperature ranges.

43. a method of making the superhard structure of polycrystalline, it comprises:

A) first area of formation polycrystalline material;

C) pressure that the first and second zones is applied greater than 4GPa also continues Preset Time with the temperature that is higher than 1200 ℃; And

D) pressure and temperature is reduced to environmental condition, so that the one or more difference on the physical property cause compression in the second area adjacent with described exposed surface; Wherein, first area or other zone have the maximum heat coefficient of expansion of polycrystalline body, and first area or other zone are by the second area that formed by one or more materials with less thermal coefficient of expansion or one or more other zone and separate with the peripheral Free Surface of polycrystalline superhard material body; Wherein each zone comprises a plurality of polycrystalline superhard material crystal grain.

44. described method according to claim 43, wherein, the one or more difference on the described physical property are to form the difference of thermal coefficient of expansion of one or more materials in the first and second zones and/or the difference of elastic modelling quantity.

45. according to claim 43 or 44 described methods, also comprise, exerted pressure in the first and second zones and the step of temperature before, first area, second area and matrix are placed in the container, and wherein, exerted pressure in the first and second zones and the step of temperature comprises: the container that comprises described the first and second zones and matrix is applied described pressure and temperature.

46. described method according to claim 45, wherein, the step that matrix is placed in the container comprises: will be placed in the container by the matrix that cemented metal carbide forms.

47. described method according to claim 46, wherein, the step that matrix is placed in the container comprises: will be placed in the container by the matrix that cobalt-cemented tungsten carbide forms.

48. each described method in 47 also comprises forming the 3rd zone, the 4th zone, the 5th zone and the 6th zone according to claim 45; Six zones, first area to the are axisymmetric, and second area to the six zones are adjacent with the first area, and each zone in second area to the six zones has the thermal coefficient of expansion less than the first area.

49. described method according to claim 48 comprises:

A. the first area is arranged between second area and the matrix;

B. the 3rd region adjacent is arranged and is arranged on matrix and polycrystalline material body at the interface in the first area; The 3rd zone is positioned at and forms the peripheral Free Surface of part of polycrystalline material body, and the 3rd zone is between first area and matrix;

C. with the 4th region adjacent in the 3rd region division, and the 4th zone is positioned at the peripheral Free Surface place of polycrystalline material;

D. with the 5th region adjacent in the 4th zone and second area setting, and make second area and the 4th regional separating; And

E. the 6th region adjacent is arranged in the first area, and first area and matrix are separated.

50. a drill bit or cutter or be used for the element of drill bit or cutter comprise according to claim 1 each described superhard structure in 42.

51. one kind basic as with reference to the method for the superhard structure of the described formation of any one embodiment of the embodiment of explaination in the accompanying drawings.

52. one kind basic such as the described superhard structure of any one embodiment with reference to the embodiment that explains in the accompanying drawings.

53. one kind basic as with reference to the described drill bit of any one embodiment or the cutter of the embodiment of explaination in the accompanying drawings or be used for the assembly of drill bit or cutter.