WC含量对TiC-Ni-Mo系硬质合金组织与性能的影响

摘要

在TiC-Ni-Mo系硬质合金中添加了5%、10%、15%和20%(质量分数,下同)WC.测定了WC含量不同的TiC-Ni-Mo系硬质合金的显微组织和力学性能,以揭示WC含量对该硬质合金组织和性能的影响.结果表明,WC溶解于TiC,形成了包裹着TiC的环形Ti(WC,Mo)C固溶体;一定范围内的WC添加量使合金强度提高,而过量的WC添加使硬质合金产生更多孔隙,导致强度降低.含15% WC的TiC-Ni-Mo硬质合金抗弯强度和硬度最高,分别为858.8 MPa和89.4 HRA.%5%,10%,15% and 20%(by mass,the same below)WC were added to TiC-Ni-Mo cemented carbide. The TiC-Ni-Mo cemented carbide with different WC contents was subjected to microstructural survey and mechanical property measurements to identify the problem how the structure and properties of the cemented carbide are affected by the WC content. The results showed that WC was dissolved into TiC to form a ring Ti(WC,Mo)C solid solution which was wrapped in TiC,and that the addition of a certain amount of WC rendered bending strength of the cemented carbide higher. The excessive addition of WC, however, leaded to the decrease of the bending strength because of formation of pores in it. The TiC-Ni-Mo cemented carbide with 15% WC exhibited the highest bending strength and hardness,reaching 858.8 MPa and 89.4 HRA respectively.