CN102747243B - Process for preparing grapheme modified hard alloy - Google Patents

Process for preparing grapheme modified hard alloy Download PDF

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Publication number
CN102747243B
CN102747243B CN201210262916.5A CN201210262916A CN102747243B CN 102747243 B CN102747243 B CN 102747243B CN 201210262916 A CN201210262916 A CN 201210262916A CN 102747243 B CN102747243 B CN 102747243B
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graphene
powder
hard alloy
brazing
sintering
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CN102747243A (en
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王永富
陈名海
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Suzhou Yongpu Carbide Tool Co., Ltd.
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王永富
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Abstract

The invention discloses a process for preparing a grapheme modified hard alloy. Preferably, the process comprises the steps of dispersing graphene oxide uniformly to form a suspension dispersion liquid, then mixing the liquid with nano W powder, nano Co and/or nano Ni powder and Cr2O3 powder, subjecting to process steps such as ball milling, drying, pelleting, press forming and sintering, and obtaining a target product. According to the process, a traditional powder metallurgy technology is used, the carbonization and sintering densification process is finished once by addition of nano high-activity constituents, rapid preparation of hard alloy products is achieved, the production efficiency and the overall performance of the hard alloy are greatly improved, and the process is applicable to large-scale industrial production and compatible and integrated with existing hard alloy industry preparation processes.

Description

A kind of preparation method of Graphene brazing
Technical field
The present invention relates to a kind of preparation method of Wimet, specially refer to a kind of preparation method of Wimet of Graphene modification.
Background technology
Wimet is a kind of alloy material of being made up by powder metallurgical technique of the hard compounds of refractory metal and matrix metal.Wimet has that hardness is high, wear-resisting, intensity and a series of premium propertiess such as toughness is better, heat-resisting, corrosion-resistant, particularly its high rigidity and wear resistance, even also substantially remain unchanged at the temperature of 500 ℃, in the time of 1000 ℃, still have very high hardness, be widely used as industrial cutting tool, mine drill, wearing piece, precision component etc.Preparation method is mainly take powder metallurgy process as main in tradition hard carbide industry, by carbide and metal adhesive mixing compression moulding, forms fine and close alloy through oversintering.Therefore the industrial raw material of Wimet uses carbide in a large number, and its preparation method is to be mainly solid state sintering reaction preparation method, is a kind of preparation method of consuming time, power consumption.Directly, using metal-powder or oxide compound as raw material, once complete carbonization and sintering densification process in sintering process, shortened process greatly, reduces energy consumption, raises the efficiency.The patent of invention of publication number CN101624673A discloses a kind of method of preparing Wimet take Tungsten oxide 99.999, metal Co powder, carbon black as raw material one step, but be mixed with Wimet because feed particles is excessive with conventional metals powder and carbon dust, carbon dust is difficult to effectively be formed on metal-powder coated outside structure, carburizing reagent is inhomogeneous causes tissue defects segregation serious, is greatly restricting the enforcement of this method.The development of nanotechnology has brought new thinking of development to cemented carbide industry, has promoted the development of the technology of preparing of high-performance superfine Wimet.The patent of invention of publication number CN102061401A has disclosed a kind of adds nano-carbon powder using nanometer W powder and superfine metal Ni powder or Co powder as raw material, and a step is prepared the method for Wimet.But in the method, carbon content distributes still to be improved.
Summary of the invention
The object of the present invention is to provide a kind of high efficiency preparation method of Wimet of Graphene modification, it makes full use of the features such as the high reactivity that Graphene ultra-thin two-dimension sheet structure has, huge specific surface area and superior comprehensive mechanical property thereof, realize carbonization and sintering densification object by a step in hard alloy sintering process, realize enhancing and the modification to Wimet mechanical property by graphene nanometer sheet simultaneously.
For achieving the above object, the present invention has adopted following technical scheme:
A preparation method for Graphene brazing, is characterized in that, the method is: it is by after the mixture of graphene oxide or graphene oxide and carbon dust is dispersed in forms dispersion liquid in water and/or organic solvent, then with Cr 2o 3powder, nanometer W powder and cobalt nanopowders and/or Ni powder are mixed to form hard alloy material, then make target product through ball milling, dry, granulation, compression moulding, degreasing and sintering circuit successively.
As one of preferred scheme, in the method, be to form after slurry pre-advanced undue loose the mixture of graphene oxide or graphene oxide and carbon dust, then with Cr 2o 3powder, nanometer W powder, cobalt nanopowders and/or Ni powder are mixed to form hard alloy material.
As one of better embodiment, described Cr 2o 3the content of powder in hard alloy material is 3-5wt%.
As one of preferred scheme, in described hard alloy material, the consumption of graphene oxide or graphene oxide and carbon dust is to calculate acquisition according to the carbon content of W powder carbonization technique and sintering process conditions needs, and interpolation scope is hard alloy material weight percent 1-10%.
As one of preferred scheme, in the method, be by ultrasonic, grinding, ball milling and high speed shear dispersing technology any one and the mixture of graphene oxide or graphene oxide and carbon dust is dispersed in and in water and/or organic solvent, forms dispersion liquid, described organic solvent is at least selected from ethanol, N, dinethylformamide, tetrahydrofuran (THF), any one in N, N-N,N-DIMETHYLACETAMIDE and toluene.
As one of better embodiment, in ball milling operation, rotational speed of ball-mill 100-250 rev/min, Ball-milling Time 12-96 hour.
As one of better embodiment, in granulating working procedure, also having added consumption is the forming agent of hard alloy material weight 1-10%, and described forming agent is at least selected from any one in polyvinyl alcohol, rubber and paraffin.
As one of better embodiment, in compression moulding operation, pressing pressure is 200-400 MPa.
As one of better embodiment, in degreasing process, skimming temp is 300-450 ℃, temperature rise rate 0.5-2 ℃/min, and insulation is more than 3 minutes.
As one of better embodiment, sintering circuit adopts any one in rare gas element sintering, vacuum sintering and low pressure sintering technique, and sintering temperature is 1300-1500 ℃.
Compared with prior art, the present invention at least tool have the following advantages:
(1) adopt high reactivity Graphene and metal-powder, oxide powder as the raw material of preparing Wimet, in sintering process, a step realizes carbonization and sintering, there is the feature of efficient quick, especially adopt graphene oxide as added ingredients, utilize its surface with a large amount of oxy radicals and easily disperse, highly active feature, its good distribution is formed to dispersion liquid in the media such as ethanol and add again, can effectively overcome traditional carbon dust and add the poor deficiency of homogeneity;
(2) utilize graphene oxide to there is huge surface-area, and be the feature of ultra-thin pliable and tough sheet structure, make it to adsorb and be wrapped in raw metal powder surface by simple physical, and then in subsequent ball milling process, realize with the good compound of metal-powder and embed, good distribution in matrix, thereby realize and make homogeneous microstructure in follow-up sintering process, reduce sintering defect;
(3) Graphene is reduced rapidly in follow-up sintering process, and react with matrix Wimet, regulate the carbon content in Wimet, because it has the activity more much higher than conventional graphite powder, therefore can make hard alloy substrate carbon content more even, improve and organize homogeneity;
(4) feature such as superelevation mechanical strength and snappiness of utilizing Graphene to have excellent comprehensive mechanical property and having concurrently, strengthens toughening effect with remaining Graphene performance, realizes the lifting to Wimet mechanical property.
Accompanying drawing explanation
Fig. 1 is preparation technology's schema of Graphene brazing in the present invention;
Fig. 2 is the electron scanning micrograph of composite granule after the embodiment of the present invention 1 ball milling mixes;
Fig. 3 is the fracture electron scanning micrograph of the embodiment of the present invention 1 obtained sample;
Fig. 4 is the fracture electron scanning micrograph of the embodiment of the present invention 3 obtained samples.
Embodiment
As previously mentioned, for the not enough of existing hard alloy production process and by problems such as the Cemented Carbide Properties of its generation are limited, this case contriver is through studying for a long period of time and putting into practice, the efficient preparation technology of Wimet of the present invention has been proposed, its principal feature is, adopt prior powder metallurgy technique, by adding nanometer high-activity component (Graphene), being conducive to improve carbon content distributes, and to realize mechanics enhancing toughness reinforcing simultaneously, realize the lifting to traditional CEMENTED CARBIDE PRODUCTION efficiency and Cemented Carbide Properties, be applicable to industrialized production, and with current Cemented Carbide Industry preparation technology mutually compatibility integrate with, significant to promoting Cemented Carbide Industry development.
Further say, the nanometer high-activity component in the present invention comprises grapheme material, particularly graphene oxide, and it adds as carbon source component, and meanwhile, the present invention also adds using metal W powder as hard phase group constituent element.The present invention can once complete carbonization, sintering densification process, realizes the quick preparation of hart metal product.And, this case contriver is after a large amount of practices, also find very unexpectedly, can there is effective alloying reaction with matrix metal powder in graphene oxide, and the mechanics of Wimet is strengthened and toughness reinforcing, this may to have huge specific surface area relevant with high chemically reactive with graphene oxide, and the comprehensive mechanical property that also may have with Graphene, as relevant with features such as high-flexibilities in high strength.
As one of preferred embodiment, the high efficiency preparation method of Graphene brazing of the present invention can be: the graphene oxide that calculates proportioning is scattered in to ethanolic soln and forms even suspended dispersed liquid, subsequently with nanometer W powder, nano Co or Nano Ni Powder end, and Cr 2o 3powder mixes, and through processing steps such as ball milling, dry, granulation, compression moulding, sintering, prepares the Wimet of Graphene modification.Wherein Cr 2o 3be as grain growth inhibitor, its addition is 3-5% with respect to the weight percent of hard alloy material.
Further, the high efficiency preparation method of this Graphene brazing can comprise the steps:
Step 1, add and in ethanolic soln, be dispersed into unit for uniform suspension calculating the graphene oxide of proportioning;
Step 2, mix with graphene oxide alcohol dispersion liquid calculating nanometer W powder, cobalt nanopowders or the Ni powder of proportioning, and add the Cr of ball milling in advance 2o 3powder slurries, subsequently by ball milling, realizes good mixing by Graphene and nano metal powder and oxide powder;
Step 3, powder drying;
Step 4, granulation;
Step 5, mold pressing compression moulding;
Step 6, vacuum degreasing, remove forming agent;
Step 7, sinter molding.
The graphene oxide adding in step 1 can be individual layer, few layer and multilayer graphene oxide, and the carbon content that its metering proportion needs according to W powder carbonization technique and sintering process conditions is calculated; Also can control in the situation of carbon total amount, add the mixture of graphene oxide and carbon dust with arbitrary proportion; Dispersing technology can be any one of the dispersing technologies such as ultrasonic, grinding, ball milling, high speed shear;
In step 2, rotational speed of ball-mill is preferably 100-250 rev/min, and Ball-milling Time is preferably 12-96 hour;
The forming agent adding in step 4 can be any one in polyvinyl alcohol, rubber, paraffin, polyoxyethylene glycol, and its consumption is preferably and accounts for hard alloy material weight percent 1-10%;
Step 5 pressing pressure is preferably 200-400 MPa;
Step 5 skimming temp is preferably 300-450 degree, and temperature rise rate is preferably 0.5-2 degree/min, and insulation is preferably 30 minutes-5 hours;
In step 6, sintering temperature is preferably 1300-1500 degree, can adopt any one sintering process in rare gas element sintering, vacuum sintering, low pressure sintering.
embodiment 1the high efficiency preparation method of this Graphene brazing is:
To adopt in ultrasonic dispersion and ethanol with respect to the graphene oxide of hard alloy material weight percent 5%, subsequently by nanometer W powder, cobalt nanopowders, Cr 2o 3powder adds mixing, 200 revs/min of ball millings 24 hours in planetary ball mill, with after through vacuum-drying, sneak into respect to the polyvinyl alcohol adhesive granulation of hard alloy material weight percent 3wt%, 350 MPa compression moldings, 0.5 degree/min and be warming up to 350 degree degreasing 3 hours, 1350 degree vacuum sintering densifications, obtain the Wimet of Graphene modification.
embodiment 2:the difference of the present embodiment and embodiment 1 is, wherein Graphene addition is 1wt%, and its mechanical property is in table 1.
embodiment 3:the difference of the present embodiment and embodiment 1 is, wherein Graphene addition is 7.5wt%, and its mechanical property is in table 1.
embodiment 4:the difference of the present embodiment and embodiment 1 is, wherein Graphene addition is 10wt%, and its mechanical property is in table 1.
embodiment 5:the difference of the present embodiment and embodiment 1 is, graphene oxide dispersion employing grinding distribution, and employing diameter 1 mm granulated glass sphere, agitation grinding disperses, and its mechanical property is in table 1.
embodiment 6:the difference of the present embodiment and embodiment 1 is, graphene oxide dispersion employing Ball milling, and employing diameter 5 mm sintered carbide balls, planetary type ball-milling disperses, and its mechanical property is in table 1.
embodiment 7:the difference of the present embodiment and embodiment 1 is, adopts rubber gasoline solution as binding agent, and its mechanical property is in table 1.
embodiment 8:the difference of the present embodiment and embodiment 1 is, adopts paraffin as binding agent, and its mechanical property is in table 1.
The mechanical property of the obtained target product of table 1 embodiment 1-8
Sample Flexural strength (GPa) Hardness (HRA)
Embodiment 1 1.85 87.9
Embodiment 2 1.68 86.8
Embodiment 3 1.90 88.2
Embodiment 4 1.78 86.5
Embodiment 5 1.83 88.2
Embodiment 6 1.81 88.1
Embodiment 7 1.80 88.3
Embodiment 8 1.83 88.1
More than explanation, and the embodiment shown on drawing, can not resolve the design philosophy surely of the present invention that is limited.In technical field of the present invention, holding the identical the knowledgeable of knowing can change technical thought of the present invention with various form improvement, such improvement and change are interpreted as belonging in protection scope of the present invention.

Claims (9)

1. the preparation method of a Graphene brazing, it is characterized in that, the method is: it is by after the mixture of graphene oxide or graphene oxide and carbon dust is dispersed in forms dispersion liquid in water and/or organic solvent, then with nanometer W powder, cobalt nanopowders and/or Ni powder and Cr 2o 3powder is mixed to form hard alloy material, then makes target product through ball milling, dry, granulation, compression moulding, degreasing and sintering circuit successively;
Wherein, the 1-10wt% that the consumption of described graphene oxide or graphene oxide and carbon dust is hard alloy material.
2. the preparation method of Graphene brazing according to claim 1, it is characterized in that, in the method, be that the mixture of graphene oxide or graphene oxide and carbon dust is formed after slurry through disperseing in advance, then mix with nanometer W powder and cobalt nanopowders and/or Ni powder, thereafter with Cr 2o 3powder is mixed to form hard alloy material.
3. the preparation method of Graphene brazing according to claim 1 and 2, is characterized in that, described Cr 2o 3the content of powder in hard alloy material is 3-5wt%.
4. the preparation method of Graphene brazing according to claim 1 and 2, it is characterized in that, in the method, be by ultrasonic, grinding, ball milling and high speed shear dispersing technology any one and the mixture of graphene oxide or graphene oxide and carbon dust is dispersed in and in water and/or organic solvent, forms dispersion liquid, described organic solvent is at least selected from ethanol, N, dinethylformamide, tetrahydrofuran (THF), any one in N, N-N,N-DIMETHYLACETAMIDE and toluene.
5. the preparation method of Graphene brazing according to claim 1, is characterized in that, in ball milling operation, and rotational speed of ball-mill 100-250 rev/min, Ball-milling Time 12-96 hour.
6. according to the preparation method of Graphene brazing described in any one in claim 1-2, it is characterized in that, in granulating working procedure, also having added consumption is the forming agent of hard alloy material weight 1-10%, and described forming agent is at least selected from any one in polyvinyl alcohol, rubber and paraffin.
7. according to the preparation method of Graphene brazing described in any one in claim 1-2, it is characterized in that, in compression moulding operation, pressing pressure is 200-400MPa.
8. according to the preparation method of Graphene brazing described in any one in claim 1-2, it is characterized in that, in degreasing process, skimming temp is 300-450 ℃, temperature rise rate 0.5-2 ℃/min, and insulation is more than 3 minutes.
9. according to the preparation method of Graphene brazing described in any one in claim 1-2, it is characterized in that, sintering circuit adopts any one in rare gas element sintering, vacuum sintering and low pressure sintering technique, and sintering temperature is 1300-1500 ℃.
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CN102965590B (en) * 2012-11-20 2015-12-09 江苏高博智融科技有限公司 A kind of brazing and preparation thereof
CN103193225A (en) * 2013-04-23 2013-07-10 江苏金桥盐化集团利海化工有限公司 Preparation method for nano metal oxide graphene composite material
CN103286309B (en) * 2013-05-07 2015-06-17 锡山区羊尖泓之盛五金厂 Hard metal used for drilling bit
CN106747433B (en) * 2017-02-28 2020-05-08 安徽拓吉泰新型陶瓷科技有限公司 Zirconia-based nano ceramic tool and die material and preparation method thereof
CN108034847A (en) * 2017-10-20 2018-05-15 苏州欧美克合金工具有限公司 A kind of hard alloy degreasing of graphene modification, sintering process
CN110164751A (en) * 2018-02-05 2019-08-23 北京欧美中科学技术研究院 A kind of preparation method of graphene high-efficiency energy-saving lamp
CN109702187A (en) * 2019-02-28 2019-05-03 中国地质大学(武汉) A kind of tungsten alloy composite powder of graphene toughening and its preparation method and application
CN111485156B (en) * 2020-04-28 2021-08-06 湖南金雕能源科技有限公司 Preparation method of wear-resistant tungsten carbide alloy material

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CN1644281A (en) * 2005-01-12 2005-07-27 哈尔滨工业大学 Method for adding carbon nanometer tube adjustable hard alloy carbon content

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CN1644281A (en) * 2005-01-12 2005-07-27 哈尔滨工业大学 Method for adding carbon nanometer tube adjustable hard alloy carbon content

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