CN111375763B - AlN-based surface-layer beta-phase-removed gradient hard alloy cutter material and preparation method thereof - Google Patents

AlN-based surface-layer beta-phase-removed gradient hard alloy cutter material and preparation method thereof Download PDF

Info

Publication number
CN111375763B
CN111375763B CN201811612835.7A CN201811612835A CN111375763B CN 111375763 B CN111375763 B CN 111375763B CN 201811612835 A CN201811612835 A CN 201811612835A CN 111375763 B CN111375763 B CN 111375763B
Authority
CN
China
Prior art keywords
powder
aln
phase
sintering
stage
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201811612835.7A
Other languages
Chinese (zh)
Other versions
CN111375763A (en
Inventor
杨天恩
熊计
王棕世
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sichuan University
Original Assignee
Sichuan University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sichuan University filed Critical Sichuan University
Priority to CN201811612835.7A priority Critical patent/CN111375763B/en
Publication of CN111375763A publication Critical patent/CN111375763A/en
Application granted granted Critical
Publication of CN111375763B publication Critical patent/CN111375763B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/10—Sintering only
    • B22F3/1017—Multiple heating or additional steps
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/10—Sintering only
    • B22F3/1017—Multiple heating or additional steps
    • B22F3/1021—Removal of binder or filler
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C29/00—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides
    • C22C29/02—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides
    • C22C29/06—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbides, but not containing other metal compounds
    • C22C29/067—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbides, but not containing other metal compounds comprising a particular metallic binder
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C29/00—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides
    • C22C29/02—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides
    • C22C29/06—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbides, but not containing other metal compounds
    • C22C29/08—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbides, but not containing other metal compounds based on tungsten carbide
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
    • B22F2005/001—Cutting tools, earth boring or grinding tool other than table ware
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
    • B22F2009/043—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling by ball milling

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Powder Metallurgy (AREA)

Abstract

The invention discloses an AlN-based surface layer beta-phase-removing gradient hard alloy cutter material and a preparation method thereof, wherein Co powder, Ni powder, (W, Ti) C powder, W powder, WC powder and AlN powder are used as raw materials for preparation, and the surface layer beta-phase-removing gradient hard alloy cutter material is obtained through three times of short-time heat preservation treatment and four times of long-time heat preservation treatment. In particular, AlN as a nitrogen source does not have a strong thermodynamic coupling effect between Al and N, so Al in the surface layer does not diffuse into the internal region where nitrogen activity is high, thereby reducing the problem of subsurface β phase aggregation.

Description

AlN-based surface-layer beta-phase-removed gradient hard alloy cutter material and preparation method thereof
Technical Field
The invention belongs to the field of hard alloy cutter materials, and particularly relates to a surface de-beta-phase gradient hard alloy cutter material, in particular to preparation of a surface de-beta-phase gradient hard alloy cutter material taking AlN as a nitrogen source.
Background
When carbon steel and alloy steel are continuously machined, the chips and the front tool face of the tool have large friction, and the average temperature of a cutting area is high, so that the hard alloy tool is required to have higher high-temperature hardness, wear resistance, adhesion resistance and oxidation resistance. Compared with YG hard alloy (hard alloy taking WC as hard phase), YT hard alloy (hard alloy taking WC as main hard phase and Ti cubic phase in a certain proportion as second hard phase) has higher chemical stability and hardness and stronger plastic deformation resistance at high temperature due to the introduction of the Ti cubic phase, thereby meeting the requirements of continuous cutting processing of carbon steel and alloy steel.
However, since the Ti-containing cubic phase is a brittle phase as compared with the YG-based cemented carbide, the introduction thereof causes the YT-based cemented carbide to be deteriorated in strength and toughness, which is disadvantageous for the interrupted cutting machining of carbon steel and alloy steel. When a tool is used for machining a workpiece with grooves, grooves or holes on the surface or for intermittent cutting such as milling, the tool is subjected to periodic mechanical load and alternating contact stress, and when the toughness of the tool material is insufficient, a notch is formed in a cutting edge to form a sharp edge. Therefore, interrupted cutting of carbon steel and alloy steel requires high strength and toughness of the tool edge. The adoption of the surface layer beta-phase-removed gradient hard alloy as the tool material for machining carbon steel and alloy steel by interrupted cutting is a solution.
The outer layer of the surface layer beta-phase-removed gradient hard alloy is removed with brittle Ti-containing cubic hard phase and is rich in a tough metal binding phase, the hard alloy is equivalent to YG hard alloy and has high strength and good toughness, and the inner part of the hard alloy is still YT hard alloy and keeps high hardness and high plastic deformation resistance. Therefore, when the surface layer beta-phase-removed gradient hard alloy is used as a tool material for the intermittent cutting of carbon steel and alloy steel, the surface layer has high toughness, the cutting edge of the tool is not easy to break, and the problem of brittle failure during the intermittent cutting processing of the carbon steel and the alloy steel can be solved.
Nitrogen sources for preparing surface layer beta-phase-removed gradient hard alloy at present are mainly Ti (C, N), TiN and N2And nitriding. However, when Ti (C, N) or TiN is used as a nitrogen source of the surface layer β -phase-removed gradient cemented carbide, Ti in the surface layer β -phase diffuses into the highly active N due to a strong thermodynamic coupling effect between Ti and N after decomposition to form a β -phase-removed layer, which causes β -phase aggregation in an inner region (subsurface layer) of the boundary of the β -phase-removed layer, thus aggravating the nonuniformity of the structure, and causes the subsurface layer to have reduced performance due to large brittleness of the β -phase; through N2When the nitrogen source is obtained by nitriding, the working procedures and cost are increased, the process is complex, and the stability of the product is easily influenced.
Disclosure of Invention
In order to solve the above problems, the present inventors have made intensive studies, and as AlN powder is used as a nitrogen source, since there is no strong thermodynamic coupling effect between Al and N, Al in the surface layer does not diffuse into the internal region where nitrogen activity is high, and therefore, the problem of beta phase aggregation in the subsurface layer is reduced, and at the same time, Al remaining in the surface layer dissolves in the binder and has a function of solid-solution strengthening the binder phase; further, Al has an effect of suppressing the deformation of the cutting edge, thereby stabilizing the machining accuracy. Meanwhile, the surface layer beta-phase-removed gradient hard alloy is prepared by a segmented heat-preservation vacuum sintering process in the process, so that the anti-tipping surface layer beta-phase-removed gradient hard alloy cutter material taking AlN as a nitrogen source is obtained.
The invention provides a preparation method of a surface layer beta-phase-removed gradient hard alloy cutter material based on AlN, which is embodied in the following aspects:
(1) a preparation method of a surface layer beta-phase-removed gradient hard alloy cutter material based on AlN comprises the following steps:
step 1, mixing materials: mixing Co powder, Ni powder, (W, Ti) C powder, W powder, WC powder and AlN powder;
step 2, adding the mixture into a ball mill, grinding, filtering, drying and pressing into a green body;
and 3, vacuum sintering, wherein the vacuum sintering comprises a vacuum sintering initial stage, a forming agent removing stage, a degassing pre-sintering stage, a solid phase sintering stage and a gradient sintering stage.
(2) The method according to the above (1), wherein in the step 1, the weight contents of the components are as follows: 2-8% of Co powder, 2-8% of Ni powder, 4-15% of (W, Ti) C powder, 0.5-3% of W, 0.1-2% of AlN powder and the balance of WC powder; preferably, the Co powder accounts for 4-6%, the Ni powder accounts for 4-6%, the (W, Ti) C powder accounts for 8-12%, the W powder accounts for 1-2.5%, the AlN powder accounts for 0.3-1.5%, and the balance is WC powder.
(3) The method according to the above (1) or (2), wherein, in the step 1, the particle diameters of the respective components are as follows: the particle size of Co powder is 0.6-2 μm, the particle size of Ni powder is 1.2-5.0 μm, the particle size of (W, Ti) C powder is 1.2-6 μm, the particle size of W powder is 0.5-1.5 μm, the particle size of AlN powder is 0.2-15 μm, and the particle size of WC powder is 2.0-10 μm; preferably, the particle size of the Co powder is 0.8-1.5 μm, the particle size of the Ni powder is 1.5-4.0 μm, the particle size of the (W, Ti) C powder is 1.5-4.5 μm, the particle size of the W powder is 0.8-1.2 μm, the particle size of the AlN powder is 0.5-13 μm, and the particle size of the WC powder is 5.0-7.5 μm.
(4) The method according to one of the above (1) to (3), wherein, in step 2, before step 1, the AlN powder is optionally subjected to modification treatment to obtain modified AlN of which the surface is coated with oleic acid; preferably, the modification treatment of the AlN powder is performed as follows: preparing 30-50% of AlN powder and an organic solvent into a suspension by mass percent, adding 0.5-4 vol% of oleic acid (cis-octadec-9-enoic acid), and performing ultrasonic dispersion treatment for 10-60 min.
(5) The method according to one of the above (1) to (4), wherein, in the grinding in step 2,
2-8 mm WC-8% Co hard alloy balls, such as 6mm WC-8% Co hard alloy balls, are adopted; and/or
The weight ratio of the ball material is (5-15) to 1, such as 10: 1; and/or
Absolute ethyl alcohol is used as a grinding medium, and the addition amount of the absolute ethyl alcohol is preferably 100-500 mL.
(6) The method according to one of the above (1) to (5), wherein an SD rubber forming agent is added after the drying in step 2, and then secondary drying is performed; preferably, the addition amount of the SD rubber forming agent is 4-7%.
(7) The method according to one of the above (1) to (6), wherein, in step 3, the vacuum sintering initial stage is sequentially subjected to three short-time heat-preservation treatments: (1) placing the green body in a vacuum furnace, heating to 130-170 ℃ at the speed of 1-5 ℃/min, and preserving heat for 5-20 min, wherein the vacuum degree is kept at 5-30 Pa; (2) heating to 250-290 ℃ at the speed of 2-6 ℃/min, and preserving the heat for 10-30 min, wherein the vacuum degree is kept at 5-30 Pa; (3) heating to 340-380 ℃ at the speed of 0.5-3.5 ℃/min, and keeping the temperature for 20-60 min, wherein the vacuum degree is kept at 15-50 Pa.
(8) The method according to one of the above (1) to (7), wherein, in step 3,
the following treatment is carried out at the stage of removing the forming agent: heating to 420-460 ℃ at the speed of 0.4-1.2 ℃/min, preserving the temperature for 40-80 min, and removing the forming agent under the vacuum degree of 15-50 Pa; and/or
The following treatment is carried out in the degassing and pre-sintering stage: heating to 540-580 ℃ at the speed of 0.5-3.5 ℃/min, preserving the heat for 40-80 min, and finishing degassing and presintering under the vacuum degree of 15-50 Pa.
(9) The method according to one of the above (1) to (8), wherein, in step 3,
the following treatments are carried out in the solid phase sintering stage: heating to 1190-1240 ℃ at the speed of 2-6 ℃/min, preserving the heat for 40-80 min, and finishing solid phase stage sintering under the vacuum degree of 5-30 Pa; and/or
The following treatments are carried out in the gradient sintering stage: heating to 1420-1460 ℃ at the speed of 2-6 ℃/min, preserving the heat for 40-120 min, and completing gradient sintering under the vacuum degree of 10-40 Pa.
The invention also provides the surface layer beta-phase-removed gradient hard alloy cutter material prepared by the preparation method in the first aspect.
Drawings
FIG. 1 is a view showing the microstructure of materials obtained in examples 1 to 2 and comparative examples 1 to 2;
FIG. 2 shows X-ray diffraction patterns of the surface layers of the materials obtained in examples 1 to 2 and comparative examples 1 to 2;
FIG. 3 shows the surface scan elemental profiles of the material sections obtained in example 1 and comparative example 1;
fig. 4 shows a fracture structure diagram of the materials obtained in example 1 and comparative example 1.
Detailed Description
The features and advantages of the present invention will become more apparent and appreciated from the following detailed description of the invention.
The invention provides a preparation method of a surface layer beta-phase-removed gradient hard alloy cutter material based on AlN, which comprises the following steps:
step 1, mixing materials: mixing Co powder, Ni powder, (W, Ti) C powder, W powder, WC powder and AlN powder.
Wherein, the invention adopts high-purity AlN powder, and the purity is over 99.5 percent.
In the invention, AlN powder is used as a nitrogen source, wherein strong thermodynamic coupling action does not exist between Al and N, so that Al in the surface layer can not diffuse to an internal region with high nitrogen activity, thereby reducing the problem of beta phase aggregation of a subsurface layer and improving the uniformity of the structure.
According to a preferred embodiment of the present invention, in step 1, the weight content of each component is: 2-8% of Co powder, 2-8% of Ni powder, 4-15% of (W, Ti) C powder, 0.5-3% of W powder, 0.1-2% of AlN powder and the balance of WC powder.
In a further preferred embodiment, in step 1, the weight content of each component is as follows: 4-6% of Co powder, 4-6% of Ni powder, 8-12% of (W, Ti) C powder, 1-2.5% of W powder, 0.3-1.5% of AlN powder and the balance of WC powder.
In a further preferred embodiment, in step 1, the weight content of each component is: 5% of Co powder, 5% of Ni powder, 10% of (W, Ti) C powder, 1.5% of W powder, 0.5-1.2% of AlN powder and the balance of WC powder.
According to a preferred embodiment of the present invention, in step 1, the particle sizes of the components are as follows: the particle size of Co powder is 0.6-2 μm, the particle size of Ni powder is 1.2-5.0 μm, the particle size of (W, Ti) C powder is 1.2-6 μm, the particle size of W powder is 0.5-1.5 μm, the particle size of AlN powder is 0.2-15 μm, and the particle size of WC powder is 2.0-10 μm.
In a further preferred embodiment, in step 1, the particle size of each component is as follows: the grain size of Co powder is 0.8-1.5 mu m, the grain size of Ni powder is 1.5-4.0 mu m, the grain size of W, Ti C powder is 1.5-4.5 mu m, the grain size of W powder is 0.8-1.2 mu m, the grain size of AlN powder is 0.5-13 mu m, and the grain size of WC powder is 5.0-7.5 mu m.
According to a preferred embodiment of the present invention, before step 1, the AlN powder is optionally subjected to a modification treatment to obtain modified AlN, the surface of which is coated with oleic acid.
In a further preferred embodiment, the modification treatment of the AlN powder is performed as follows: preparing 30-50% of AlN powder and an organic solvent into a suspension by mass percent, adding 0.5-4 vol% of oleic acid (cis-octadec-9-enoic acid), and performing ultrasonic dispersion treatment for 10-60 min.
In a further preferred embodiment, NH is used3·H2Adjusting the pH value of O and HCOOH to 7.5-11.5 to coat a layer of oleic acid (chemical formula: C) on the AlN powder18H34O2) Molecular membrane
Among them, the aim of modifying the AlN powder is to promote uniform dispersion thereof.
In the invention, AlN is used as a nitrogen source for preparing the surface layer beta-phase-removed gradient hard alloy, and compared with the traditional Ti (C, N) or TiN nitrogen source, the nitrogen source reduces the beta-phase aggregation of the subsurface layer of the alloy and improves the uniformity of the structure.
In addition, AlN is used as a nitrogen source, and Al remains and dissolves in the adhesive to form (Ni, Co) when AlN in the surface layer is decomposed3Al has the function of solid solution strengthening of a binding phase, improves mechanical properties such as strength, hardness and impact toughness of a surface layer, further strengthens the anti-tipping effect, and prolongs the service life of the cutter.
Meanwhile, Al has the function of inhibiting the deformation of the tool nose, so that the Al reserved on the surface layer can improve the deformation resistance of the cutting edge and the tool nose, thereby stabilizing the dimensional accuracy of the machined part.
And 2, adding the mixture into a ball mill, grinding, filtering, drying and pressing into a green body.
According to a preferred embodiment of the present invention, 2 to 8mm of WC-8% Co cemented carbide balls, for example 6mm WC-8% Co cemented carbide balls, are used in the grinding in step 2.
In a further preferred embodiment, the weight ratio of the pellets is (5-15): 1, for example 10: 1.
In a further preferred embodiment, absolute ethyl alcohol is used as the grinding medium, and the addition amount is preferably 100-500 mL.
According to a preferred embodiment of the present invention, in the grinding in step 2, the grinding speed is 50 to 90r/min, and the grinding time is 24 to 96 hours.
In a further preferred embodiment, in the step 2, the polishing speed is 50 to 70r/min, and the polishing time is 36 to 72 hours.
According to a preferred embodiment of the present invention, in the step 2, the drying is performed at 70 to 140 ℃ under a vacuum degree of 1 to 8 Pa.
In a more preferred embodiment, in the step 2, the drying is performed at 85 to 120 ℃ under a vacuum degree of 1 to 5 Pa.
According to a preferred embodiment of the present invention, after the drying in step 2, an SD rubber forming agent is added, followed by secondary drying.
In a further preferred embodiment, the amount of the SD rubber molding agent added is 4 to 7%.
In a further preferred embodiment, the secondary drying is performed at 85 to 120 ℃ under a vacuum of 1 to 5 Pa.
And 3, vacuum sintering, wherein the vacuum sintering comprises a vacuum sintering initial stage, a forming agent removing stage, a degassing pre-sintering stage, a solid phase sintering stage and a gradient sintering stage.
According to a preferred embodiment of the present invention, in step 3, the vacuum sintering initial stage is sequentially subjected to three short-time heat preservation treatments: (1) placing the green body in a vacuum furnace, heating to 130-170 ℃ at the speed of 1-5 ℃/min, and preserving heat for 5-20 min, wherein the vacuum degree is kept at 5-30 Pa; (2) heating to 250-290 ℃ at the speed of 2-6 ℃/min, and preserving the heat for 10-30 min, wherein the vacuum degree is kept at 5-30 Pa; (3) heating to 340-380 ℃ at the speed of 0.5-3.5 ℃/min, and keeping the temperature for 20-60 min, wherein the vacuum degree is kept at 15-50 Pa.
In a further preferred embodiment, in step 3, the vacuum sintering initial stage comprises three short-time heat-preservation treatments: (1) placing the green body in a vacuum furnace, heating to 140-160 ℃ at the speed of 1-3 ℃/min, and keeping the temperature for 8-12 min, wherein the vacuum degree is kept at 10-20 Pa; (2) heating to 260-280 ℃ at the speed of 3-5 ℃/min, and preserving the heat for 15-25 min, wherein the vacuum degree is kept at 10-20 Pa; (3) heating to 350-370 ℃ at the speed of 1-3 ℃/min, and preserving the heat for 30-50 min, wherein the vacuum degree is kept at 20-30 Pa.
The vacuum sintering initial stage comprises three short-time heat preservation treatments, specifically, rapid heating and short-time heat preservation, wherein the rapid heating is used for improving the production efficiency, and the short-time heat preservation is used for recovering the vacuum degree and ensuring the uniform heating inside and outside the material.
According to a preferred embodiment of the present invention, in step 3, the following treatment is performed in the step of removing the forming agent: heating to 420-460 ℃ at the speed of 0.4-1.2 ℃/min, preserving the temperature for 40-80 min, and removing the forming agent under the vacuum degree of 15-50 Pa.
In a further preferred embodiment, in step 3, the following treatment is carried out in the stage of removing the forming agent: heating to 430-450 ℃ at the speed of 0.6-1.0 ℃/min, preserving the temperature for 50-70 min, and removing the forming agent under the vacuum degree of 20-30 Pa.
In the stage of removing the forming agent, the temperature rise speed is reduced, because the rubber solution is used as the forming agent, the cracking of the rubber is started at about 300 ℃ and is finished at about 450 ℃, therefore, in the stage of removing the forming agent, the gas is increased due to the cracking of the rubber, and the temperature needs to be slowly raised in order to facilitate the recovery of the vacuum degree. Further, if the removal rate of the forming agent is too high, part of the forming agent is overheated, and the forming agent is cracked to leave excess carbon in the material, and further, carburization occurs, so that a slow temperature rise is required.
According to a preferred embodiment of the invention, in step 3, the following treatment is carried out in the degassing pre-sintering phase: heating to 540-580 ℃ at the speed of 0.5-3.5 ℃/min, preserving the heat for 40-80 min, and finishing degassing and presintering under the vacuum degree of 15-50 Pa.
In a further preferred embodiment, in step 3, the following treatment is carried out in the degassing pre-sintering stage: heating to 550-570 ℃ at the speed of 1.0-3.0 ℃/min, preserving the heat for 50-70 min, and finishing degassing and presintering under the vacuum degree of 20-40 Pa.
In the degassing and pre-sintering stage, metal oxide is reduced, for example, Co oxide is reduced below 500 deg.c, the vacuum degree in the furnace is reduced by the gas produced in the reduction reaction, and the heat insulating step is set to facilitate the volatilization of the gas in the material and raise the vacuum degree inside the furnace.
According to a preferred embodiment of the invention, in step 3, the following treatment is carried out in the solid phase sintering phase: heating to 1190-1240 ℃ at the speed of 2-6 ℃/min, preserving the heat for 40-80 min, and finishing solid phase stage sintering under the vacuum degree of 5-30 Pa.
In a further preferred embodiment, in step 3, the following treatment is carried out in the solid phase sintering stage: heating to 1200-1220 ℃ at the speed of 3-5 ℃/min, preserving the heat for 50-70 min, and finishing solid phase stage sintering under the vacuum degree of 10-20 Pa.
Wherein, a heat preservation step is set up in the solid phase stage sintering, gas is volatilized as much as possible before liquid phase appears, if the liquid phase appears without complete degassing, the opening of the pore is closed, and permanent pores are left in the alloy. In addition, the surface layer beta-phase-removed gradient alloy material contains Ti, and Ti is easily oxidized. The reduction of Ti oxides can only be completed at 1000-1250 deg.C, so that the heat preservation at this stage is favorable for the reduction of the combined oxygen in the Ti-containing solid solution.
According to a preferred embodiment of the invention, in step 3, the gradient sintering phase is subjected to the following treatment: heating to 1420-1460 ℃ at the speed of 2-6 ℃/min, preserving the heat for 40-120 min, and completing gradient sintering under the vacuum degree of 10-40 Pa.
In a further preferred embodiment, the following treatment is carried out in the gradient sintering stage: heating to 1430-1450 ℃ at the speed of 3-5 ℃/min, preserving the heat for 50-90 min, and completing gradient sintering under the vacuum degree of 15-30 Pa.
Wherein, because the gas is removed in the solid phase sintering stage, the temperature rise speed in the gradient sintering stage can be higher but not too high, otherwise the inside and outside uniform heating of the sintered alloy can be influenced, and the product is deformed or even cracked due to the local shrinkage. In addition, the gradient sintering heat preservation stage belongs to liquid phase sintering, and the heat preservation at the stage is favorable for volatilization of AlN decomposed gas and diffusion of Ti in a liquid bonding phase to form a surface beta-phase-removing layer.
Therefore, in the preparation method, three short-time heat preservation treatments and four long-time heat preservation treatments are adopted to obtain the cemented carbide cutter material with excellent performance.
The second aspect of the invention provides the surface layer beta-phase-removed gradient cemented carbide tool material prepared by the method of the first aspect of the invention.
According to a preferred embodiment of the invention, the material is made of a composition comprising Co powder, Ni powder, (W, Ti) C powder, W powder, AlN powder and WC powder.
In a further preferred embodiment, in the composition: 2-8% of Co powder, 2-8% of Ni powder, 40-15% of (W, Ti) C powder, 0.5-3% of W powder, 0.1-2% of AlN powder and the balance of WC powder.
In a still further preferred embodiment, in the composition: the particle size of each component is as follows: the particle size of Co powder is 0.6-2 μm, the particle size of Ni powder is 1.2-5.0 μm, the particle size of (W, Ti) C powder is 1.2-6 μm, the particle size of W powder is 0.5-1.5 μm, the particle size of AlN powder is 0.2-15 μm, and the particle size of WC powder is 2.0-10 μm.
In the present invention, the β phase: the cubic phase in cemented carbide in the present invention mainly refers to a (W, Ti) C solid solution phase having a face-centered cubic (f.c.c) structure.
The invention has the following beneficial effects:
(1) AlN powder is used as a nitrogen source, so that beta phase aggregation of the alloy subsurface layer is reduced, and the tissue uniformity is improved;
(2) AlN powder is used as nitrogen source, and Al is still remained and dissolved in the adhesive to form (Ni, Co)3Al has the function of solid solution strengthening of a binding phase, improves the mechanical properties of the surface layer such as strength, hardness, impact toughness and the like, and further strengthens the anti-tipping effect, thereby prolonging the service life of the cutter;
(3) the Al reserved on the surface layer can improve the deformation resistance of the cutting edge and the tool nose, thereby stabilizing the dimensional accuracy of the machined part.
Examples
The invention is further described below by means of specific examples. However, these examples are only illustrative and do not limit the scope of the present invention.
Example 1
Weighing the raw materials according to the weight percentage to prepare the surface layer beta-phase-removed gradient hard alloy, wherein AlN powder with the average particle size of 1.0 mu m accounts for 1.2 percent, Co powder with the particle size of 1.17 mu m accounts for 5 percent, Ni powder with the particle size of 2.65 mu m accounts for 5 percent, C powder with the particle size of 2.80 mu m accounts for 10 percent, W powder with the particle size of 1.06 mu m accounts for 1.52 percent, and the balance is WC powder with the particle size of 6.44 mu m.
Firstly, AlN powder and absolute ethyl alcohol are prepared into 40 percent suspension by mass percent for ultrasonic treatment, the adding amount of oleic acid (chemical formula: C18H34O2) is 2 percent by volume, and NH is adopted3·H2Adjusting pH to 9.5 with O and HCOOH, and ultrasonic dispersing for 40 min.
Then adding the pretreated AlN powder, Co powder, Ni powder, (W, Ti) C powder, W powder and WC powder into a roller ball mill together for grinding, wherein the grinding balls are WC-8 wt% Co hard alloy balls with the diameter of 6mm, the weight ratio of the ball materials is 10:1, the grinding medium is absolute ethyl alcohol, the adding amount of the absolute ethyl alcohol is 300mL, and the grinding is carried out for 48 hours at the speed of 60 r/min. After grinding, the hard alloy slurry is filtered by a 400-mesh screen and dried in vacuum at 5Pa and 90 ℃. The addition amount of the dried SD rubber forming agent is 5.5 percent by weight; after being mixed evenly, the mixture is dried again under vacuum at 5Pa and 90 ℃, the dried mixture is filtered by a 80-mesh screen and is pressed into a green body under 400 MPa.
Placing the green body in a vacuum furnace, (1) heating to 150 ℃ at the speed of 3 ℃/min, and preserving the heat for 10min under the vacuum degree of 15 Pa; heating to 270 deg.C at a rate of 4 deg.C/min, and maintaining at 15Pa vacuum degree for 20 min; heating to 360 deg.C at a rate of 1.5 deg.C/min, and maintaining at 25Pa vacuum degree for 40 min; (2) heating to 440 ℃ at the speed of 0.8 ℃/min, and keeping the temperature for 60min under the vacuum degree of 25Pa to remove the forming agent; (3) heating to 560 ℃ at the speed of 2 ℃/min, and preserving the heat for 60min under the vacuum degree of 25Pa to finish degassing and presintering; (4) heating to 1210 deg.C at a rate of 3.6 deg.C/min, and maintaining at 15Pa vacuum degree for 60min to complete solid phase stage sintering; (5) heating to 1440 ℃ at the speed of 3.8 ℃/min, and preserving the temperature for 60min under the vacuum degree of 20Pa to finish the gradient sintering.
The thickness of the surface layer of the gradient cemented carbide prepared in example 1 is about 23 μm, the microstructure is shown in fig. 1 (a), the XRD spectrum of the surface layer is shown in fig. 2 (a), the distribution of the sectional elements Ti, Co and Ni is shown in fig. 3 (a) - (c) in sequence, and the fracture structure of the surface layer is shown in fig. 4 (a).
The density of the material prepared in example 1 was 99.4%, hardness (Hv)30) 1632.4MPa, transverse rupture strength 1992.3MPa, and fracture toughness 11.82MPa m-1/2The relative magnetic saturation was 5.16%, and the coercive force was 13.32 kA/m.
Example 2
The procedure of example 1 was repeated except that: the amount of AlN added was 0.6%.
The thickness of the surface layer of the gradient cemented carbide prepared in example 2, which is removed from the beta phase, is about 14 μm, the microstructure is shown in (b) of fig. 1, and the XRD spectrum of the surface layer is shown in (b) of fig. 2.
Example 2The density of the prepared material is 99.5 percent, and the hardness (Hv)30) 1607.3MPa, transverse rupture strength 1906.5MPa, and fracture toughness 11.25MPa m-1/2The relative magnetic saturation was 6.36%, and the coercive force was 13.79 kA/m.
Example 3
The procedure of example 1 was repeated except that AlN was added in an amount of 0.3%.
The density of the material prepared in example 3 was 99.6%, hardness (Hv)30) 1573.3MPa, transverse rupture strength 1783.8MPa, and fracture toughness 10.91MPa m-1/2The relative magnetic saturation was 6.51%, and the coercive force was 12.24 kA/m.
Example 4
The procedure of example 1 was repeated except that AlN was added in an amount of 1.5%.
Example 5
The procedure of example 1 was repeated except that AlN was added in an amount of 0.9%. The density of the material prepared in example 5 was 99.5%, hardness (Hv)30) 1612.8MPa, transverse rupture strength 1977.1MPa, and fracture toughness 11.40MPa m-1/2The relative magnetic saturation was 5.98% and the coercive force was 13.66 kA/m.
Comparative example
Comparative example 1
The procedure of example 1 was repeated except that: no AlN was added.
The microstructure of the prepared hard alloy is shown in (c) in fig. 1, the surface XRD spectrum is shown in (c) in fig. 2, the distribution of the section elements Ti, Co and Ni is shown in (d) to (f) in fig. 3, and the surface fracture structure is shown in (b) in fig. 4.
The density of the material prepared in comparative example 1 was 99.8%, hardness (Hv)30) 1566.2MPa, transverse rupture strength of 1707MPa, and fracture toughness of 10.73MPa m-1/2The relative magnetic saturation was 6.82%, and the coercive force was 11.91 kA/m.
Compared to example 1, no de- β phase surface layer was formed, indicating that AlN is a necessary condition for forming a de- β phase surface layer in the present system. XRD analysis showed that a solid solution of (W, Ti) C containing Ti was still present in the surface layer. EDS (electron-dispersive spectroscopy) analysis shows that elements such as Ti, Co, Ni and the like are uniformly distributed, while in example 1, the Ti element is removed in the surface layer, Al is still remained, Co and Ni are high in the surface layer, and the content in the interior is low, which indicates that the binder is enriched in the surface layer. The fracture structure of the surface layer showed that the average WC size of the surface layer was smaller than that in example 1 because the presence of the Ti-containing solid solution had the effect of suppressing grain growth, but the brittle phase broke through the crystal because the Ti-containing solid solution was a brittle phase. The transverse rupture strength was lower than that of example 1, indicating that the de-beta surface layer had the effect of increasing the toughness of the alloy.
Comparative example 2
The procedure of example 1 was repeated except that: the AlN addition amount was 1.8%.
The thickness of the surface layer of the gradient cemented carbide prepared in comparative example 2, which is removed from the beta phase, is about 36 μm, the microstructure is shown in (d) of fig. 1, and the XRD spectrum of the surface layer is shown in (d) of fig. 2.
The density of the material prepared in comparative example 2 was 99.2%, hardness (Hv)30) 1648.7MPa, transverse rupture strength 1633.1MPa, and fracture toughness 9.5MPa m-1/2The relative magnetic saturation was 4.59% and the coercive force was 8.71 kA/m.
The de-beta phase surface layer thickness is thicker compared to example 1, indicating that as the AlN content in the cemented carbide increases, the nitrogen content increases, and therefore the nitrogen concentration gradient between the cemented carbide surface layer and the sintering environment increases, which increases the nitrogen activity gradient, resulting in an increase in the inward titanium diffusion flux, and therefore the gradient layer thickness. XRD analysis showed that when AlN was added in a large amount, precipitation of (Ni, Co) occurred in the structure3An Al phase. Although the surface layer of the beta-phase becomes thicker, the beta-phase is removed due to (Ni, Co)3The precipitation of Al phase and the excessive addition of AlN lead to the reduction of the transverse rupture strength and the rupture toughness of the alloy, and the reduction is obvious.
Comparative example 3
The procedure of example 1 was repeated except that: the AlN in example 1 was replaced with Ti (C, N) in an equimolar amount to that of AlN, and the other conditions were not changed.
Comparative example 3 the material obtained had a density of 99.1% and a hardness of (C:)Hv30) 1616.6MPa, transverse rupture strength 1835.7MPa, and fracture toughness 10.86MPa m-1/2。
Comparative example 4
The procedure of example 1 was repeated except that: the AlN in example 1 was replaced with Ti (C, N) in an equimolar amount to AlN and Al powder in an equimolar amount to AlN, and the other conditions were not changed.
Comparative example 4 the material obtained had a density of 99.3% and a hardness (Hv)30) 1504.9MPa, and 1645.8MPa of transverse rupture strength.
Among them, comparison of comparative example 3 and comparative example 4 shows that if aluminum powder is added alone to the system, the performance of the material is adversely affected.
Comparative example 5
The procedure of example 1 was repeated except that: the AlN of example 1 was replaced with TiN in an equimolar amount to that of AlN, and the other conditions were not changed.
Comparative example 5 the material obtained had a density of 98.4% and a hardness (Hv)30) 1635.7MPa, transverse rupture strength 1766.1MPa, and fracture toughness 10.25MPa m-1/2。
Comparative example 6
The procedure of example 1 was repeated except that: the AlN in example 1 was replaced with TiN in an equimolar amount to AlN and Al powder in an equimolar amount to AlN, with the other conditions being unchanged.
Comparative example 6 the material obtained had a density of 98.7% and a hardness (Hv)30) 1479.5MPa, and 1619.6MPa of transverse rupture strength.
Also, comparing comparative example 5 and comparative example 6, it was found that if aluminum powder alone is added to the system, the properties of the material are adversely affected.
The invention has been described in detail with reference to specific embodiments and illustrative examples, but the description is not intended to be construed in a limiting sense. Those skilled in the art will appreciate that various equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its embodiments without departing from the spirit and scope of the present invention, which fall within the scope of the present invention. The scope of the invention is defined by the appended claims.

Claims (13)

1. The preparation method of the AlN-based surface layer beta-phase-removed gradient hard alloy cutter material is characterized by comprising the following steps of:
step 1, mixing materials: mixing Co powder, Ni powder, (W, Ti) C powder, W powder, WC powder and AlN powder;
step 2, adding the mixture into a ball mill, grinding, filtering, drying and pressing into a green body;
step 3, vacuum sintering, which comprises a vacuum sintering initial stage, a forming agent removing stage, a degassing pre-sintering stage, a solid phase sintering stage and a gradient sintering stage; in the step 1, the weight contents of the components are as follows: 2-8% of Co powder, 2-8% of Ni powder, 4-15% of (W, Ti) C powder, 0.5-3% of W powder, 0.1-2% of AlN powder and the balance of WC powder.
2. The method according to claim 1, wherein in step 1, the weight content of each component is as follows: 4-6% of Co powder, 4-6% of Ni powder, 8-12% of (W, Ti) C powder, 1-2.5% of W powder, 0.3-1.5% of AlN powder and the balance of WC powder.
3. The method according to claim 2, wherein in step 1, the particle sizes of the components are as follows: the particle size of Co powder is 0.6-2 μm, the particle size of Ni powder is 1.2-5.0 μm, the particle size of (W, Ti) C powder is 1.2-6 μm, the particle size of W powder is 0.5-1.5 μm, the particle size of AlN powder is 0.2-15 μm, and the particle size of WC powder is 2.0-10 μm.
4. The method according to claim 3, wherein in step 1, the particle sizes of the components are as follows: the grain size of Co powder is 0.8-1.5 mu m, the grain size of Ni powder is 1.5-4.0 mu m, the grain size of W, Ti C powder is 1.5-4.5 mu m, the grain size of W powder is 0.8-1.2 mu m, the grain size of AlN powder is 0.5-13 mu m, and the grain size of WC powder is 5.0-7.5 mu m.
5. The method of claim 1, wherein before step 1, modifying the AlN powder to obtain modified AlN coated with oleic acid on the surface; the modification treatment of the AlN powder was performed as follows: preparing 30-50% of suspension by mass of AlN powder and an organic solvent, adding 0.5-4 vol% of oleic acid, and performing ultrasonic dispersion treatment for 10-60 min.
6. The method of claim 1, wherein, in the grinding of step 2,
2-8 mm WC-8% Co hard alloy balls are adopted; and/or
The weight ratio of the ball material is (5-15) to 1; and/or
Absolute ethyl alcohol is used as a grinding medium.
7. The method of claim 6, wherein, in the grinding of step 2,
adopting 6mm WC-8% Co hard alloy balls; and/or
The weight ratio of the ball material is 10: 1; and/or
The addition amount of the absolute ethyl alcohol is 100-500 mL.
8. The method of claim 1, wherein the drying in step 2 is followed by adding an SD rubber forming agent and then performing a secondary drying.
9. The method according to claim 8, wherein the SD rubber forming agent is added in an amount of 4 to 7 wt%.
10. The method according to claim 1, wherein in step 3, the vacuum sintering initial stage is sequentially subjected to three short-time heat-preservation treatments: (1) placing the green body in a vacuum furnace, heating to 130-170 ℃ at the speed of 1-5 ℃/min, and preserving heat for 5-20 min, wherein the vacuum degree is kept at 5-30 Pa; (2) heating to 250-290 ℃ at the speed of 2-6 ℃/min, and preserving the heat for 10-30 min, wherein the vacuum degree is kept at 5-30 Pa; (3) heating to 340-380 ℃ at the speed of 0.5-3.5 ℃/min, and keeping the temperature for 20-60 min, wherein the vacuum degree is kept at 15-50 Pa.
11. The method according to claim 1, wherein, in step 3,
the following treatment is carried out at the stage of removing the forming agent: heating to 420-460 ℃ at the speed of 0.4-1.2 ℃/min, preserving the temperature for 40-80 min, and removing the forming agent under the vacuum degree of 15-50 Pa; and/or
The following treatment is carried out in the degassing and pre-sintering stage: heating to 540-580 ℃ at the speed of 0.5-3.5 ℃/min, preserving the heat for 40-80 min, and finishing degassing and presintering under the vacuum degree of 15-50 Pa.
12. The method according to claim 1, wherein, in step 3,
the following treatments are carried out in the solid phase sintering stage: heating to 1190-1240 ℃ at the speed of 2-6 ℃/min, preserving the heat for 40-80 min, and finishing solid phase stage sintering under the vacuum degree of 5-30 Pa; and/or
The following treatments are carried out in the gradient sintering stage: heating to 1420-1460 ℃ at the speed of 2-6 ℃/min, preserving the heat for 40-120 min, and completing gradient sintering under the vacuum degree of 10-40 Pa.
13. Surface de-beta-phase gradient cemented carbide tool material prepared according to the method of any one of claims 1 to 12.
CN201811612835.7A 2018-12-27 2018-12-27 AlN-based surface-layer beta-phase-removed gradient hard alloy cutter material and preparation method thereof Active CN111375763B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201811612835.7A CN111375763B (en) 2018-12-27 2018-12-27 AlN-based surface-layer beta-phase-removed gradient hard alloy cutter material and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201811612835.7A CN111375763B (en) 2018-12-27 2018-12-27 AlN-based surface-layer beta-phase-removed gradient hard alloy cutter material and preparation method thereof

Publications (2)

Publication Number Publication Date
CN111375763A CN111375763A (en) 2020-07-07
CN111375763B true CN111375763B (en) 2021-03-16

Family

ID=71214468

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201811612835.7A Active CN111375763B (en) 2018-12-27 2018-12-27 AlN-based surface-layer beta-phase-removed gradient hard alloy cutter material and preparation method thereof

Country Status (1)

Country Link
CN (1) CN111375763B (en)

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63216942A (en) * 1987-03-05 1988-09-09 Sumitomo Electric Ind Ltd Tool for warm and hot forgings
CN102418023A (en) * 2011-11-03 2012-04-18 重庆泰蒙科技有限公司 Preparation method of coating hard alloy matrix with surface-layer beta phase removing and gamma phase enriching gradient structure
CN106702249B (en) * 2016-12-12 2018-05-22 南京航空航天大学 A kind of preparation method of gradient-structure WC-Co hard alloy
CN107190196B (en) * 2017-06-09 2019-02-22 洛阳理工学院 A kind of cutter high-wear-resistant alloy material and preparation method thereof
CN107604231B (en) * 2017-09-12 2019-04-30 河源正信硬质合金有限公司 A kind of high pressure resistant high-temperature rigid alloy and preparation method thereof
CN107964620B (en) * 2017-11-30 2020-05-01 株洲三鑫硬质合金生产有限公司 Tungsten-nickel-based enhanced hard alloy and preparation method thereof

Also Published As

Publication number Publication date
CN111375763A (en) 2020-07-07

Similar Documents

Publication Publication Date Title
CN106191608B (en) A kind of hard alloy in low cobalt of high temperature resistant, wear resistant corrosion resistant and preparation method thereof
CN109161711B (en) Superfine crystal gradient hard alloy with double-gradient-layer structure on surface and preparation method thereof
EP2433727B1 (en) Method for producing a sintered composite body
JPH02197569A (en) Coated sintered hard alloy and production thereof
CN111519115B (en) High-toughness high-wear-resistance titanium carbonitride based cermet material and preparation method thereof
CN113046612B (en) Surface layer decarburization phase gradient hard alloy material and preparation method thereof
CN111187959B (en) Metal-rich phase gradient structure titanium carbonitride base cermet and preparation method thereof
CN108588533B (en) Ti (C, N) -based metal ceramic matrix material for CVD coating and preparation method thereof
JPS594498B2 (en) Cemented carbide parts and their manufacturing method
CN111375763B (en) AlN-based surface-layer beta-phase-removed gradient hard alloy cutter material and preparation method thereof
CN108165791B (en) Preparation method of binderless superfine tungsten carbide hard alloy
JP4170402B2 (en) Titanium-based carbonitride alloy with nitrided surface region
JP6052502B2 (en) Surface coated cemented carbide cutting tool
JPS6383236A (en) Manufacture of sintered hard alloy excellent in thermal conductivity and combining high hardness with high toughness
KR101450661B1 (en) The method of preparation for ternary titanium carbonitride sintered bodies having enhanced mechanical properties and ternary titanium carbonitride sintered bodies prepared thereby
CN113088781B (en) High-entropy hard alloy and preparation method and application thereof
CN111378884B (en) Surface layer beta-phase-removed gradient hard alloy cutter material and preparation thereof
CN110512132B (en) Gradient hard alloy with long rod-shaped crystal grains as surface layer WC and no cubic phase and preparation method thereof
CN113621859B (en) YA-class gradient hard alloy material with hard surface and tough inner surface
CN114645172B (en) Submicron gradient hard alloy with surface layer having cubic phase removed and preparation method thereof
JP2002180107A (en) Method for manufacturing functionally gradient composite material
CN110923590A (en) SiC whisker toughened superfine hard alloy and preparation method and application thereof
CN113667874B (en) YA-class gradient hard alloy material and preparation method and application thereof
CN110872683B (en) Method for preparing titanium-titanium nitride composite coating on surface of stainless steel
KR101789230B1 (en) POWDER INJECTION MOLDING METHOD FOR FEBRICATING WC-Co STRUCTURE AND SYSTEM THEREOF

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant