抑制硬质合金烧结中WC晶粒长大的研究

Inhibition of WC Grain Growth during Sintering of Cemented Carbide

该文选择了VC和Cr3C2作为WC-Co硬质合金晶粒长大抑制剂,研究两种抑制剂加入量对合金组织、WC晶粒度和性能的影响以及抑制晶粒长大的机理.研究结果表明,VC和Cr3C2的加入十分有效地抑制了基体合金WC晶粒的长大,合金中的WC晶粒度随抑制剂加入量的增加而减小,可达到最小的WC晶粒度接近100nm.合金的硬度随抑制剂加入量增加而增加,但强度则下降.同时也会增加孔隙度,结果增加了脆性,降低了合金的强度.VC的有害影响比Cr3C2更大.

The effect of VC and Cr3C2 as inhibitors of grain growth on grain size and properties of cemented carbide is investigated. The mechanism of inhibiting grain growth is discussed. The results show that the growth of WC grain during sintering is effectively inhibited by addition of VC and Cr3C2. The grain size decreased with the amount of inhibitors, and WC grain size of about 100 nm can be obtained. Hardness increases with the amount of the inhibitors, but the strength decreases. Excess amount of inhibitor can result in a deposit of carbides and introduce some pores, making the alloys brittle. This effect of VC is greater than Cr3C2.