晶粒长大抑制剂对超细WC-9%Co硬质合金性能的影响

Effects of Grain Growth Inhibitors on Properties of Ultra-fine WC-9%Co Cemented Carbides

在复合抑制剂(VC/Cr3C2)的基础上,添加了不同配比的TaC,研究了TaC对超细WC-9%Co硬质合金组织结构和力学性能的影响。结果表明:添加不同配比的TaC制备的WC-9%Co硬质合金的硬度随着TaC质量分数的增加先增大后减小;TaC的加入降低了W在Co相中的固溶度,从而抑制了晶粒长大。在本实验范围内,在复合抑制剂(VC/Cr3C2)质量分数为0.6%的基础上添加质量分数0.3%的TaC,经1 390℃真空烧结后,制备的超细WC-9%Co硬质合金硬度为93.5 HRA,TRS为2 370 MPa,致密度为99.5%,磁饱和强度为13.29 G.cm3/g,矫顽磁力为31.86 kA/m,此时具有较佳的综合力学性能。

Different contents of TaC and（VC/Cr3C2） were doped as WC grain growth inhibitors in ultra-fine WC9%Co cemented carbides.The effects of TaC on the microstructure and mechanical properties of cemented carbides were researched.Results have been shown that hardness of cemented carbides increases firstly and then decreases with the increase of the TaC content.Because the existence of TaC reduces the solution degree of tungsten in Co phase,grain growth is inhibited.Under the optimum conditions of the experiment,ultra-fine WC-9%Co cemented carbides containing 0.6%（VC/Cr3C2）＋0.3%TaC（mass fraction） are prepared in vacuum sintering at temperature of 1 390 ℃,and better comprehensive mechanical properties are acheived with the relative density,HRA,TRS,magnetic saturation intensity and coercivity of 99.5%,93.5 HRA,2 370 MPa,13.29 G·cm3/g and 31.86 kA/m,respectively.