WC含量对TiCN-HfN金属陶瓷刀具材料微观组织和力学性能的影响

采用热压烧结技术制备了TiCN-HfN-WC金属陶瓷刀具材料, 研究了WC含量(质量分数)对金属陶瓷刀具材料微观组织和力学性能的影响。结果表明: TiCN-HfN-32%WC金属陶瓷刀具材料由TiCN、(Ti, Hf, W)(C, N)、WC和MoNi组成, 材料中还含有极少量的(Ti, Mo, W)(C, N)固溶体, 材料内部形成了网状骨架结构。随着添加WC质量分数的增加, 材料中晶粒粒度降低, 添加WC可抑制材料中TiCN晶粒的生长, 起到细化TiCN晶粒的作用; 材料的相对密度、硬度和断裂韧度都具有先增大后减小的变化趋势, 材料的抗弯强度逐渐增大。当WC质量分数为32%时, 材料具有相对较好的综合力学性能, 其硬度为20.2GPa, 断裂韧度为7.1MPa·m1/2, 抗弯强度为1581.3MPa。

Effect of WC content on the microstructure and mechanical properties of TiCN-HfN cermet tool materials

TiCN-HfN-WC cermet tool materials were fabricated by hot-pressed sintering technology, and the effect of WC mass fraction on the microstructure and mechanical properties of the cermet tool materials was investigated. The results show that, the TiCN-HfN-32%WC cermets are composed of TiCN, (Ti, Hf, W)(C, N), WC, and MoNi, which also contain a little amount of (Ti, Mo, W)(C, N), and the retiform skeleton structure forms inside the cermet material. With the increase of the WC content, TiCN grain becomes smaller, which indicates that WC can inhibit the TiCN grain growth and achieve the refinement of TiCN grain; meanwhile, the density, hardness, and fracture toughness of the TiCN-HfN-WC cermet also increase first and then decrease, however, the flexural strength increases gradually. When the WC mass fraction is 32%, the TiCN-HfN-WC cermet shows good comprehensive mechanical properties: the hardness is 20.2 GPa, the fracture toughness is 7.1 MPa·m1/2, and the flexural strength is 1581.3 MPa.