摘要
研究了配碳量对放电等离子烧结制备无粘结剂纳米WC硬质合金的烧结行为、相组成、致密度、硬度及晶粒大小的影响。结果表明:纯纳米WC粉直接烧结,样品的晶粒度为300～400nm,致密度及硬度均较高,但主相变为缺碳相WC1-x和W2C;配碳量为0.05%～0.25%时,样品中有少量缺碳相;配碳量为0.40%时,可以正确成相;配碳量为0.50%时,则出现游离碳;粉末配碳球磨后,因烧结过程提前到较低温度下完成,1800℃烧结时晶粒急剧长大且不均匀。
<Abstrcat>Study is made on the effects of mixed carbon content on the spark plasma sintering binder-free nanostructured WC cemented carbides in respect of the sintering behavior,phase make-up,densification,hardness and grain size.The results showed that direct sintering of pure nano-WC resulted in 300～400 nm sample with high densification and hardness,but the main phase changed into WC_(1-x) and W_2C.With 0.05～0.25% carbon mixed,there is a little WC_(1-x).With 0.4% carbon mixed,correct phase can be got.With 0.5% carbon mixed,free carbon appears.After ball mixing,the powder can be sintered at lower temperature and when sintering at 1 800 ℃ the grain grows rapidly and unevenly.
出处
《稀有金属与硬质合金》
CAS
CSCD
2005年第2期12-15,共4页
Rare Metals and Cemented Carbides
基金
北京市教委资助项目(KM200410005006)
