稀土Y_2O_3对WC-6%Co超细硬质合金组织及性能的影响

本文研究了在复合抑制剂(Cr3C2/VC/TaC)组成及含量不变的基础上,添加不同量Y2O3对WC-6%Co超细硬质合金的组织结构、磁性能及力学性能的影响。通过XRD以及性能测试,研究发现:在WC-6%Co超细硬质合金中添加Y2O3,能起到细化晶粒的效果,当添加0.2%Y2O3时,合金的晶粒最细,致密度最好,WC晶粒分布均匀;Y2O3会影响WC-6%Co超细硬质合金的磁性能,随着Y2O3含量的增加,合金的矫顽磁力增加,磁饱和强度略有降低,Y2O3能有效的改善合金的机械性能,特别是其抗弯强度。结果表明,当抑制剂配方为0.8%(Cr3C2/VC/TaC)+0.2%Y2O3时,制备的WC-6%Co超细硬质合金的机械性能具有最佳值,硬度达到94.1 HRA,抗弯强度1 770 MPa。

Effects of Y2O3 Addition on Microstructure and Properties of Ultrafine WC-6%Co Cemented Carbides

The contents of Y2O3 and(Cr3C2/VC/TaC) were doped as grain growth inhibitors in ultrafine WC-6%Co cemented carbides.The effects of Y2O3 on the microstructure,magnetic performance and mechanical properties of cemented carbides were researched.The microstructure and properties of the cemented carbide were measured by XRD detection,cobalt magnetic detection,coercive force test and other methods.Results show that Y2O3 can inhibit the grain growth.When adding 0.2%Y2O3(mass fraction),the alloy has the finest grain size and highest density,and the distribution of WC grain is uniform.Y2O3 can improve the magnetic properties of the alloys.The coercive forces of YG6 cemented carbides decrease and the magnetic saturation increase with the increase of the Y2O3 content,which shows that Y2O3 can reduce the carbon content of the alloy.At the same time,Y2O3 can improve the mechanical properties of the alloys.The hardness and TRS of WC-6%Co-0.8%(Cr3C2/VC/TaC)+0.2%TaC(mass fraction) cemented carbide are 94.1 HRA and 1 770 MPa,respectively.