CeO_(2)添加量对Ti(C,N)基金属陶瓷显微结构和力学性能的影响

Influence of CeO_(2) addition on microstructure and mechanical properties of Ti(C,N)-based cermets

采用真空烧结工艺制备了(56-x)Ti(C_(0.5),N_(0.5))-20WC-3.5Mo_(2) C-20(Co+Ni)-xCeO_(2)(x=0,0.05%,0.1%,0.2%)系列金属陶瓷,研究了CeO_(2)添加量对Ti(C,N)基金属陶瓷显微结构和力学性能的影响。结果表明:添加适量的CeO_(2)有利于Ti(C,N)金属陶瓷显微组织细化,使硬质相颗粒尺寸减小,而且分布更加均匀,从而提高其力学性能。此外,添加CeO_(2)后金属陶瓷中裂纹扩展过程产生较多的桥接现象,使其具有较高的断裂韧性。随着CeO_(2)添加量增加,Ti(C,N)金属陶瓷的密度和力学性能先增大后减小,CeO_(2)添加量为0.1%时,金属陶瓷的密度、硬度、抗弯强度和断裂韧性分别为6.51 g/cm^(3)、91.6 HRA、1577 MPa和9.11 MPa·m^(1/2)。

A series of(56-x)Ti(C_(0.5),N_(0.5))-20WC-3.5Mo_(2)C-20(Co+Ni)-xCeO_(2)(x=0,0.05%,0.1%,0.2%)cermets were prepared by vacuum sintering,and the influence of CeO_(2)addition on microstructure and mechanical properties of the Ti(C,N)-based cermets was studied.The results show that adding appropriate amount of CeO_(2)can refine the microstructure of the Ti(C,N)cermet,reduce the size of hard phase particles and make the distribution more uniform,so as to improve its mechanical properties.In addition,there are more bridging phenomena in the crack propagation process of the cermets after adding CeO_(2),which makes the cermets have higher fracture toughness.The density and mechanical properties of the Ti(C,N)cermets first increase and then decrease with the increase of CeO_(2)content.When the CeO_(2)content is 0.1%,the density,hardness,transverse rupture strength and fracture toughness of the Ti(C,N)cermets are 6.51 g/cm^(3),91.6 HRA,1577 MPa and 9.11 MPa·m^(1/2),respectively.