TiN含量对Ti(C,N)/NiCr金属陶瓷微观结构和力学性能的影响

采用粉末冶金真空烧结方法制备了Ti（C，N）／NiCr金属陶瓷．研究了TiN含量对Ti（C，N）／NiCr金属陶瓷微观结构与力学性能的影响、结果表明，TiN的加入既改变了金属陶瓷硬质相颗粒的尺寸，使其变小，也改变了硬质相颗粒的形貌，使其由圆形变为多边形；随TiN含量的增加，金属陶瓷的抗弯强度均出现先增加后降低的规律，但在较低的烧结温度下，抗弯强度在TiN含量为4％时达到最大值，而在较高的烧结温度下，抗弯强度在TiN含量为6％时达到最大值；硬度在TiN含量〈10％时变化不明显，TiN含量〉10％时硬度急剧下降；抗弯断口以穿晶解理为主要的断裂模式．

Effect of tin content on microstructures and mechanical properties of Ti(C,N)/NiCr cermets

Ti(C,N)/NiCr cermets were vacuum sintered by powder metallurgy technology. The effects of TiN additions on microstructures and mechanical properties of Ti(C, N)/NiCr cermets were investigated. Results revealed that the hard phase particles were refined and the morphology of the particles changed from a circular to a polygonal shape by the additions of TiN because of the formation of Ti(C,N) solid solution; With increasing TiN additions, the bonding strength increased to the maximum values at 4%TiN content during low sintering temperature and at 6%TiN content during high sintering temperature, respectively, and then decreased. Hardness changed little when TiN addition was less than 10%, but decreased dramatically when TiN addition exceeded 10%. Fracture photograph showed that trans-granular fracture was the main failure mode because of the good interface bonding strength between binding phase and ceramic hard phase.