A kind of plastic mould high hardness wear-resisting copper alloy and preparation method thereof
Technical field
The present invention relates to alloy material, and in particular to a kind of plastic mould high hardness wear-resisting copper alloy and its preparation side
Method.
Background technology
At present, mainly mould steel and the beallon of plastic mould material performance requirement are met.With it is widely used
Mould steel is compared, and copper alloy die has good thermal fatigue resistance, and not only thermal conductivity is high, and corrosion resistance and good,
Therefore can shortening injection molding cycle, reduce injecting products buckling deformation, effectively improve the quality and production efficiency of plastic,
It is the conventional main material of plastic mould critical component.Processing, casting in industry and in the copper alloy of powder metallurgy except beryllium is blue or green
Outside copper, general hardness is relatively low, is not appropriate for as plastic mould material.And the copper alloy as plastic mould material is mainly beryllium
Bronze, such as ZCuBe2、ZCuBe2.4Deng.Although copper beryllium mold material advantage is significantly, there is also self problem, mainly
It is that price is high, beryllium element is a toxic element again, and beallon can be only achieved high-strength high rigidity after fixation rates, but
It is that toughness is very low, limits its extensive use.
Existing low beryllium beallon has increasing application in telecommunication electronics industry, but does not solve fundamentally
The problem of certainly beryllium copper is present.Also SiC particulate Reinforced Cu (Cr) based composites for having research to prepare, reach in SiC content
During 20Vol%, hardness highest is also not above 160HV.
The content of the invention
It is an object of the invention to provide a kind of plastic mould high hardness wear-resisting copper alloy and preparation method thereof.
To reach above-mentioned purpose, present invention employs following technical scheme:
A kind of plastic mould high hardness wear-resisting copper alloy, the copper alloy is composed of the following components as mass fraction:
Mo:8~10%, Cr:8~10%, Cu:>=78% and<80%, surplus is impurity.
The density of the copper alloy is 8.3~8.4g/cm-3, consistency is 94~95%.
The hardness of the copper alloy is 38~42HRC, thermal conductivity >=80W/Km, electrical conductivity >=28%ICAS.
The copper alloy is handled successively through mechanical alloying, destressing and powder reduction by Cu powder, Mo powder and Cr powder
And hot pressed sintering is prepared from.
The above-mentioned plastic mould preparation method of high hardness wear-resisting copper alloy, comprises the following steps:
1) mechanical alloying twice
Make Cr-Mo mixed powders formation upper state Cr (Mo) prealloy solid-solution powder first with mechanical alloying, so
Cu powder and the mechanical alloying of upper state Cr (Mo) prealloy solid-solution powder are obtained into Cu (MoCr) supersaturated solid solution afterwards to close
Bronze end;
2) it is mixed into Cu (MoCr) supersaturated solid solution alloy powder after activated carbon powder and carries out destressing and powder reduction
Processing obtains powder to be sintered;
3) treat sintered powder and carry out the block copper alloy of middle pressure sintering acquisition without atmosphere protection;
Cr and Mo solid solubility in Cu is equal in terms of mass fraction in Cu (MoCr) the supersaturated solid solution alloy powder
More than 8%.
The step 1) specifically include following steps:
1.1) Mo powder and Cr powder are pressed 1:1 mass ratio is well mixed to obtain Cr-Mo mixed powders, by Cr-Mo mixed powders
Body 16~24h of mechanical lapping, is obtained using argon gas atmosphere protection in upper state Cr (Mo) prealloy solid-solution powder, process of lapping,
And take the wet mode taken of dry grinding to take out upper state Cr (Mo) prealloys solid-solution powder after the completion of grinding, it is subsequently placed in true
Dried in empty drying box;
1.2) dried upper state Cr (Mo) prealloy solid-solution powders and copper powder are pressed 1:4 mass ratio is well mixed
8~10h of mechanical lapping, is obtained using argon gas atmosphere protection in Cu (MoCr) supersaturated solid solution alloy powder, process of lapping afterwards, and
Take the wet mode taken of dry grinding to take out Cu (MoCr) supersaturated solid solutions alloy powder after the completion of grinding, be subsequently placed in vacuum
Dried in drying box.
The step 2) specifically include following steps:
Cu (MoCr) supersaturated solid solution alloy powders and activated carbon powder are pressed 100:True after 1 mass ratio is well mixed
Anneal 1h in empty tube type high temperature sintering furnace in 500~600 DEG C.
The middle pressure sintering without atmosphere protection specifically includes following steps:
A1) powder to be sintered is incorporated with the high temperature alloy die cavity of graphite paper protection, and to institute in hot-pressed sintering furnace
State powder to be sintered and apply 620~630MPa initial pressures;
A2 15~20min of pressurize) is cold-pressed under initial pressure;
A3) by step a2) after, unload and be depressed into 205~210MPa, and with 8~10 DEG C/min be heated to sintering temperature 800~
850 DEG C, then it is incubated 30~60min;
A4 stop heating after) being incubated, and cool to after room temperature, cooling release with the furnace and take out the block in high temperature alloy die cavity
Body material, that is, obtain copper alloy.
Beneficial effects of the present invention are embodied in:
Of the invention main using mechanical alloying this non-equilibrium alloy preparation technology, making Mo and Cr, both are difficult to solid solution
Alloying element in Cu realizes a large amount of solid solutions, Cr and Mo in Cu solid solubility in terms of mass fraction more than 8%, subsequent
Hot pressed sintering during, Mo, Cr have a certain degree of disperse educt, by disperse and solution strengthening collective effect so as to significantly
The hardness of Cu alloys is improved, hardness is obtained and reaches more than 38HRC, thermal conductivity reaches that more than 80W/Km Cu-Cr-Mo is closed
Gold, the alloy is that one kind can meet plastic mould material performance requirement, and the high rigidity copper alloy without beryllium.
Brief description of the drawings
Fig. 1 is upper state Cr (Mo) prealloy solid-solution powder XRD testing results that mechanical lapping is obtained;
Fig. 2 is Cu (MoCr) supersaturated solid solution alloy powder XRD testing results that mechanical lapping is obtained;
The copper alloy XRD testing results that Fig. 3 obtains for sintering.
Embodiment
The present invention is elaborated with reference to the accompanying drawings and examples, described is explanation of the invention, and unrestricted.
Embodiment
A kind of preparation method of plastic mould high hardness wear-resisting copper alloy, raw material Mo powder, Cr powder, copper powder particle size are
200 mesh, purity is 99%, and concrete technology flow process is as follows:
1st, it is 1 in mass ratio:1 uniformly mixes raw material Mo powder, Cr powder, passes through the mechanical lapping on vibration rod mill
16h, obtains in upper state Cr (Mo) prealloy solid-solution powder, process of lapping and is protected in grinding pot by vacuumizing applying argon gas atmosphere
Shield, takes the wet mode taken of dry grinding, it is ensured that powder is not oxidized in whole process, afterwards in vacuum drying chamber after the completion of grinding
Middle drying (70~80 DEG C) is stand-by;As seen from Figure 1, Mo peaks, Cr peaks have been not present in XRD results, only show that Cr (Mo) is solid
Solution peak, illustrates the solid solution process for having been realized in Mo, Cr, forms upper state Cr (Mo) prealloy solid solution of complete solid solution
Powder;
2nd, it is 1 in mass ratio by upper state Cr (Mo) prealloy solid-solution powders and copper powder after step 1:4 mixing are equal
After even, the mechanical lapping 8h on vibration rod mill is obtained in Cu (MoCr) supersaturated solid solution alloy powder, process of lapping and ground
The wet mode taken of dry grinding is taken after the completion of applying argon gas, grinding by vacuumizing in tank, it is ensured that powder is in whole process not by oxygen
Change, dry (70~80 DEG C) in vacuum drying chamber afterwards stand-by;As seen from Figure 2, it has been not present in XRD results single
Mo peaks, Cr peaks, while there is the skew of certain angle at Cu peaks, preliminary judgement Mo, Cr are solid-solution in Cu, form Cu (MoCr)
Supersaturated solid solution alloy powder (granularity is 30 microns);
3rd, it is 100 in mass ratio by Cu (MoCr) supersaturated solid solution alloy powders and activated carbon powder after step 2:1
After well mixed, anneal 1h in electron tubes type high temperature sintering furnace in 500 DEG C, and main purpose is to eliminate powder interior portion remnants
Stress, while removing in powder because of a small amount of oxygen for taking powder to be brought into operating;
4th, the powder after being handled with step 3, carries out hot pressed sintering on hot-pressed sintering furnace:
1) powder is incorporated with the high temperature alloy die cavity of high purity graphite paper protection;Plus initial pressure 630MPa;
2) pressurize 15min (room temperature) is cold-pressed under the initial pressure;
3) unload and be depressed into 210MPa;
4) power transmission heating (10 DEG C/min) is incubated 30min for 850 DEG C to sintering temperature;
5) power-off is cooled to room temperature, and sample is taken out in release;
As seen from Figure 3, Cu peaks are offset to low-angle, while asymmetric trend occur in Cu peaks, can illustrate solid solution
Mo, Cr in Cu have a certain amount of precipitation after hot pressed sintering.But for the hardness of the wear-resistant copper alloy, solution strengthening
Effect is far longer than precipitation strength effect.
The hot pressed sintering furnace structure is made up of common four columns hydraulic press and semi-open type silicon carbide rod heating furnace, without
Atmosphere protection, hydraulic press tonnage is up to 60 tons, and heating-up temperature is up to 1300 DEG C, it is ensured that middle pressure sintering process parameter is realized.
The mold materials that the present invention is used are high-temperature alloy material, and temperature in use is up to 1100 DEG C, the inscribed tool of having a sudden inspiration of die cavity
Alloying copper alloy powder end adds attached high purity graphite paper, and 1) it is acted on forms a reduction protection atmosphere at high temperature,
Ensure not aoxidize in copper alloy powder sintering process;2) it is easy to be stripped sampling after the completion of sintering.
The copper alloy prepared by embodiment is constituted as can be seen from Table 1:
The copper alloy constituent analysis testing result of table 1
Element |
Mo |
Cr |
Fe |
C |
Ni |
Al |
Si |
Cu |
Copper alloy |
9.06% |
8.08% |
2.01% |
1.23% |
0.29% |
0.26% |
0.19% |
Surplus |
It is sintering bulk that embodiment, which prepares copper alloy,:Hardness:40HRC;Thermal conductivity:80W/K·m;Electrical conductivity:29%
ICAS。
The hardness of U.S. C17200 beallon materials is 38~45HRC, and electrical conductivity is 22~28%IACS, and of the invention
The Cu alloy material hardness of preparation is 38~42HRC, and electrical conductivity is 28~30%IACS, and thermal conductivity is 80~85W/Km,
It is better than beallon in terms of structural homogenity and consistency of performance, is even more particularly to be better than beryllium copper on the polishing effect of sample
Alloy.
The present invention presses hot pressed sintering in using, and the density of powder metallurgy bulk is reached 8.3g/cm-3Left and right, consistency reaches
95% or so, the limited precipitation of Cr, Mo element in copper alloy ensures that its high rigidity, conduction, the performance of heat conduction.
Present invention process is simple, and its key is:
1st, main innovation point is that pure Cu and upper state Cr (Mo) prealloy are carried out into the preparation of secondary mechanical alloying Mo, Cr to exist
Supersaturated solid solution alloy powder in Cu.Mechanical alloying technique is utilized twice, makes Cr-Mo using mechanical alloying for the first time
Upper state Cr (Mo) prealloy solid-solution powder is formed, for the second time by pure Cu powder and upper state Cr (Mo) prealloy solid solution powder
Last mechanical alloying obtains Cu-Cr-Mo supersaturated solid solutions powder (the i.e. Cu that Cr, Mo solid solubility in Cu exceed 8wt%
(MoCr) supersaturated solid solution alloy powder).
2nd, a small amount of activated carbon powder is mixed into Cu (MoCr) supersaturated solid solution alloy powder, and entered in vacuum tube furnace
Row destressing reduced anneal, is also removed in powder while powder processing hardening is eliminated because taking what is brought into powder or subsequent operation
Part oxygen.
3rd, middle pressure sintering is proposed, without atmosphere protection, high dense sintering copper alloy bulk is obtained, it is ensured that sintered copper alloy
Bulk has high rigidity, conduction, the combination property of heat conduction.
Claimed key point:
1st, mechanical alloying technique is utilized twice, makes Cr-Mo formation upper state Cr (Mo) using mechanical alloying for the first time
Prealloy solid-solution powder, for the second time obtains Cr (Mo) prealloy solid-solution powder mechanical alloying of pure Cu powder and upper state
Obtain the Cu-Cr-Mo supersaturated solid solution powder that Cr, Mo solid solubility in Cu exceed 8wt%.
2nd, stress relief annealing and the powder reduction processing of activated carbon powder are mixed into;
3rd, the middle pressure sintering process without atmosphere protection;Pressure sintering obtains high rigidity, heat conduction, conductive copper alloy sintering in
Bulk;The limited precipitation of solid solution element Mo, Cr meets modeling to ensure copper alloy high rigidity, conduction, the performance of heat conduction in sintering bulk
Expect mould critical component performance requirement.