烧结温度对TiC_(0.7)N_(0.3)-WC-TaC-Mo-(Ni,Co)金属陶瓷材料组织与性能的影响

采用粉末冶金工艺制备TiC_(0.7)N_(0.3)-WC-TaC-Mo-(Ni,Co)金属陶瓷材料。通过密度测试仪、万能力学试验机、维氏硬度测试仪、X射线衍射分析仪和扫描电镜等方法检测金属陶瓷样品的密度、抗弯强度、硬度、物相结构和微观结构,比较分析不同烧结温度对TiC_(0.7)N_(0.3)-WC-TaC-Mo-(Ni,Co)金属陶瓷材料的组织结构和性能的影响。结果表明:烧结温度对材料的致密化过程和结构性能产生重要影响;当烧结温度为1450℃时,材料的抗弯强度达到1110MPa,显微硬度达到1200HV;材料组织致密,环形相连续分布,硬质相细小、均匀,能有效抑制在应力作用下材料内部裂纹的扩展,增加韧性断裂特征。

Effect of sintering temperature on the properties and microstructure of TiC0.7N0.3-WC-TaC-Mo-(Ni,Co) cermet

Ti(C0.7N0.3)-WC-TaC-Mo-(Ni,Co) cermets were prepared using powder metallurgy process. The density, flexure strength and Vickers hardness (HV) of the processed materials were evaluated by density balance, universal testing machine and Vickers hardness tester, while their phase composition and microstructure were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The effect of the sintering temperature on the properties of the cermet materials was studied. The results show that sintering temperature plays a significant role in the densification process and affects properties of cermet apparently. The cermet sintered at 1 450℃ exhibits maximum flexure strength of 1 110 MPa and Vickers hardness of 1 200 MPa, and presents more plastic fractural model because its rim phase and fine hard phase distributed evenly, which are helpful to prevent micro-crack propagating under stress.