( 1. 中南大学 粉末冶金国家重点实验室, 长沙 410083;
2. 华南理工大学机械工程学院, 广州 510640)
摘 要: 研究了机械合金化纳米晶WC-10Co复合粉末的真空烧结致密化行为和一般规律。结果表明: 烧结温度的提高和烧结时间的延长有利于样品的烧结致密化过程, 在1275~1300℃致密化速度快,在1300℃, 15min左右致密化过程已基本完成; VC、 Cr3C2等复合晶粒长大抑制剂含量的增加不利于致密化过程;新型晶粒长大抑制剂A可以更有效地阻碍晶粒长大;纳米晶WC-10Co-0.8VC/ Cr3C2-0.2A复合粉末压坯在1375℃, 30min烧结条件下, 所得的密度为14.48g/cm3, 晶粒尺寸约为180nm。
关键字: 纳米晶硬质合金; 真空烧结; 烧结致密化; 晶粒长大;抑制剂
( 1. State Key Laboratory of Powder Metallurgy,
Central South University,Changsha 410083, China;
2. School of Mechanical Engineering,
South China University of Technology,Guangzhou 510640, China)
Abstract: Vacuum sintering densification behavior of nanoscrytalline WC-10Co composite powders produced by mechanical alloying was studied. The results show that the increments of sintering temperature and time promote densification process which is faster during 1275-1300℃, and almost the whole densification can be achieved at about 1300℃ after 15min. The increasing content of VC and Cr3C2 composite grain growth inhibitors is not beneficial to improving densification. The new grain growth inhibitor A was proved to inhibit grain growth more effectively. The density of 14.48g/cm3 and the grain size of about 180nm can be achieved at 1375℃ after 30min from nano-grained WC-10Co-0.8VC/Cr3C2-0.2A composite powders.
Key words: nano-grained cemented carbide; vacuum sintering; sintering densification; grain growth; inhibitor