W粉粒径和烧结温度对一步法制备WC-10%Co硬质合金组织性能的影响  

Effect of W Particle Size and Sintering Temperature on Microstructure and Properties of WC-10%Co Cemented Carbide Prepared by One-step Method

作　　者：朱敏 鲁忠臣[1,4,5] 刘伟锋 龙坚战 张卫兵 李剑峰[1,3] 曾美琴 徐涛[1,3] Zhu Min;Lu Zhongchen;Liu Weifeng;Long Jianzhan;Zhang Weibing;Li Jianfeng;Zeng Meiqin;Xu Tao(State Key Laboratory of Cemented Carbide,Zhuzhou Hunan 412000,China;School of Materials Science and Engineering,South China University of Technology,Guangzhou Guangdong 510640,China;Zhuzhou Cemented Carbide Group Corp.Ltd.,Zhuzhou Hunan 412000,China;School of Mechanical and Automotive Engineering,South China University of Technology,Guangzhou Guangdong 510640,China;Key Laboratory of Advanced Energy Storage Materials of Guangdong Province,Guangzhou Guangdong 510640,China)

机构地区：[1]华南理工大学材料科学与工程学院,河南株洲412000 [2]广东省先进储能材料重点实验室,广东广州510640 [3]硬质合金国家重点实验室,河南株洲412000 [4]华南理工大学机械与汽车工程学院,广东广州510640 [5]株洲硬质合金集团有限公司,广东广州510640

出　　处：《硬质合金》2022年第5期350-363,共14页Cemented Carbides

基　　金：硬质合金国家重点实验室开放课题(ZY(JC)-2021-40)。

摘　　要：等离子球磨“碳化烧结一步法”制备WC-Co硬质合金有利于板状晶WC的形成和形态控制。本文进一步研究了等离子球磨W-C-Co复合粉末的组织演变,着重考察原始W粉粒径和烧结温度对WC-10%Co硬质合金组织、性能的影响。结果表明,等离子球磨使W颗粒显著呈片状,并增加其中位错等缺陷,提高粉末中的变形储能,同时增加了W/C反应界面,均有利于WC板状晶的生成;随着原始W粉粒径增加,等离子球磨所制备的层片状聚集体的片径越大,其生成的板状WC晶粒也越大,板状WC晶粒的定向排列程度也越高;随着烧结温度增加,WC晶粒的长径比和板状WC晶粒的定向排列程度有所提高。当原始W粉粒径为2.5μm、烧结温度1440℃时,所制备的WC-10%Co硬质合金样品垂直于压制方向截面的横向断裂强度、硬度和断裂韧性分别为3542 MPa、14.896 GPa、16.73 MPa·m^(1/2);平行于压制方向截面的硬度和断裂韧性为13.975 GPa、15.06 MPa·mm^(1/2)。The application of"synchronous carbonization and sintering method"based on the plasma milling technologyis very beneficial to the preparation and morphology control of plate-like structured WC-Co cemented carbide.In this paper,the microstructure evolution of W-C-Co composite powder fabricated by plasma milling was studied,and emphasis was made to the effects of original W powder particle size and sintering temperature on the microstructure and properties of WC-10%Co cemented carbide.It was found that plasma milling significantly enhances formation of plate-like W particles,increases the dislocation density,the stored deformation energy and the W/C reaction interface in powder,all of which were beneficial to to form plate-like structured WC grains.With the increase of the original W powder particle size,the lamellar aggregates prepared by plasma milling are larger,and the grain sizes and the arrangement degree of oriented plate-like WC grains are also increased.With the increase of sintering temperature,the aspect ratio and the arrangement degree of oriented plate-like WC grains increase within a certain extent.With a combination of the original W powder particle size of 2.5μm and the sintering temperature of 1440℃,the TRS,hardness and fracture toughness on the section which was vertical to the pressing direction of WC-10%Co cemented carbide are 3542 MPa,14.896 GPa and16.73 MPa·m^(1/2),respectively;the hardness and fracture toughness on the section which was parallel to the pressing direction are 13.975 GPa and 15.06 MPa·mm^(1/2),respectively.

关 键 词：等离子球磨 WC-CO硬质合金 板状WC 碳化烧结一步法 

分 类 号：TG135.5[一般工业技术—材料科学与工程]