WANG Lujie ¹, LIU Xuejian ², QIAO Zhuhui ¹

(1. The State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Science, Lanzhou 730000, Gansu, China; 2. The State Key Lab of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China)

Abstract: Silicon nitride ceramics are typical structural ceramics with excellent comprehensive properties, while brittleness is still their shortcoming in application. Introduction of ductile metal particles is regard as an important method to adjust the brittleness of ceramics. In recent years, attempts have been made to improve the properties of silicon nitride ceramics by introducing metal particles. Nevertheless, because the high sintering temperature of silicon nitride ceramics is much higher than the melting point of most metals, together with problems, such as thermal expansion coefficient mismatch, high temperature chemical incompatibility, poor interface wettability and so on, the introduction of metal into silicon nitride ceramics could bring great difficulties. In this work, the related works of the introduction of different metals into silicon nitride ceramics as second phase in recent years will be reviewed, including the solutions to tackle the above problems and enhancement in performance. Finally, the problems and existing solution of metal introduction into silicon nitride ceramics are summarized and a simple prospect is given.

Key words: silicon nitride; metal; fracture toughness; tribological properties; thermal stress