碳含量对WC-3Co-3Ni粗晶硬质合金组织和性能的影响

Effect of Carbon Content on Microstructure and Properties of WC-3Co-3Ni Coarse Grained Cemented Carbide

为探究碳含量对Co-Ni复合粘结相粗晶硬质合金组织与性能的影响,采用光学显微镜、洛氏硬度计、矫顽磁力计和钴磁测量仪研究了不同碳含量下WC-3Co-3Ni粗晶硬质合金组织结构与性能的变化规律。结果表明:随着球磨时间增加,合金的矫顽磁力增加,在球磨22 h时矫顽磁力达到最大值。随着碳含量增加,WC晶粒形貌表现为棱角更加分明,溶解-析出过程使WC晶粒变粗,抗弯强度升高,硬度降低。当延长球磨时间时,碳含量降低比碳含量增加所引起的合金硬度的增幅更大。

In order to explore the effect of carbon content on the microstructure and properties of coarse grained cemented carbide with Co-Ni composite binder phase, the change rules of microstructure and pro-perties of WC-3 Co-3 Ni coarse grained cemented carbides with different carbon contents were studied by optical microscope, Rockwell hardness tester, coercivity tester and cobalt magnetometer.The results show that the coercive force of alloy increases with the increase of ball milling time, and reaches its maximum value when the ball milling time reaches 22 h.With the increase of carbon content, the WC grain morpho-logy is more angular, the dissolution-precipitation process makes WC grains coarser, the bending strength increases and the hardness decreases.When the milling time is prolonged, the increase of hardness caused by the decrease of carbon content is greater than that caused by the increase of carbon content.