气压烧结无粘结相超细硬质合金WC-0.27VC-0.53Cr_3C_2的配碳研究  

Research of carbon addition of pressure sintering superfine WC-0.27VC-0.53Cr_3C_2 cemented carbide

作　　者：高建祥[1,2] 范景莲[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083 [2]湖南工业大学冶金工程学院,湖南株洲412000

出　　处：《粉末冶金技术》2012年第5期334-340,共7页Powder Metallurgy Technology

基　　金：国家自然科学基金资助项目(50874122);国家杰出青年科学基金资助项目(50925416)

摘　　要：无粘结相WC基硬质合金具有WC-Co合金无可比拟的优异的耐磨性和抗腐蚀性,目前是硬质合金重要的研究领域之一。研究了纳米配碳对高能球磨WC-0.27VC-0.53Cr3C2纳米复合粉气压烧结制品的致密化及相结构的影响,初步探讨了合金的硬度、断裂韧度等性能。研究结果表明:球磨时间达到15h时,粉末BET粒度和晶粒尺寸分别为77nm、20nm,粉末碳含量下降约0.2%(质量分数,下同),氧含量增加约0.5%(质量分数,下同)。随配碳量的增加,合金的致密度先增高后减低;配碳量为0.6%时,合金的相对密度最高,约为99.5%;配碳量<0.6%时,合金中产生了W2C相,但W2C含量随配碳量增加而逐渐减少。本研究中粉末适宜配碳量为0.6%,此时合金的晶粒度为204.5nm,硬度(HV0.5)和断裂韧度分别为29.6GPa和7.07MPa.m1/2。Binderless WC hardmetals have better wear resistance and corrosion resistance than WC-Co cemented carbides. It＇ s one of the important research fields of cemented carbides at present. It＇ s mainly studied in this paper that the influence of carbon addition on sintering densifieation and phase compositions of WC-0.27VC-0. 53Cr3C2 nano powders, and some properties such as hardness, fracture toughness are also discussed. The results show that when the high energy ball milling for 15 hours, powder BET particle size and grain size are 77nm, 20nm respectively. Total carbon is down about 0.2 wt% and oxygen content increases about 0. 5 wt %. Density of alloys increases firstly and than decreases with the increasing amount of carbon. The relative density of alloys is about 99.5% when carbon addition is 0. 6wt% , and at this time the relative density of alloys is the highest. With the increasing amount of carbon, the content of W2C in alloys gradually reduces. When the carbon addition is 0. 6wt% , all of the diffraction peaks shown are WC phase. In this study the proper amount of carbon addition is about 0. 6wt%. At this time grain size of alloys is 204. 5 nm. Hardness （HV0.5） and the fracture toughness（Kic ） are 29.6 GPa and 7.07 MPa · m1/2 respectively.

关 键 词：气压烧结 无粘结相硬质合金 超细 配碳 

分 类 号：TF125.3[冶金工程—粉末冶金]