碳纳米管对硬质合金WC晶粒及强度的影响

Effect of carbon nanotubes on WC grains and strength of cemented carbide

以碳纳米管为增强相,WC-10Co硬质合金为基体,采用湿法球磨工艺将多壁碳纳米管(Multiwalled carbon nanotubes,MWCNTs)和WC-10Co硬质合金粉料充分混合,通过真空烧结制成CNTs增强的WC-10Co硬质合金试样。采用SEM观测MWCNT在硬质合金基体中的分布和烧结后硬质合金微观结构。SEM显示碳纳米管嵌插在WC晶粒之间,抑制WC晶粒生长,使WC晶粒得到细化。试样横向断裂强度达到1 780 MPa,对比未增强试样提高了7.8%。

A kind of cemented carbide was fabricated by the vacuum sintering process using multi-walled carbon nanotubes(MWCNTs)as the reinforcing phase and WC-10 Co as the matrix.The MWCNTs and WC-10 Co composite powder were mixed by wet-process ball-milling.The distribution of MWCNTs in cemented carbide matrix and the microstructure of sintered cemented carbide were observed by SEM.The results show that the carbon nanotubes were inserted in the WC grains boundary.This inhibited the growth of WC grains and finer grains were gained.The transverse rupture strength increased 7.8% and reached 1 780 MPa.,