标题：Microstructure, mechanical properties and thermal shock behavior of h-BN-SiC ceramic composites prepared by spark plasma sintering
作者：Zhai, Fengrui; Li, Shuang; Sun, Jialin; Yi, Zhongzhou
作者机构：[Zhai, Fengrui; Sun, Jialin] Univ Sci & Technol Beijing, Sch Mat Sci & Engn, Beijing 100083, Peoples R China.; [Zhai, Fengrui; Yi, Zhongzhou] Honghe 更多
通讯作者地址：[Yi, ZZ]Honghe Univ, Coll Sci, Mengzi 661199, Yunnan, Peoples R China.
关键词：h-BN-SiC; Microstructure; Mechanical properties; Thermal shock behavior;; Spark plasma sintering
摘要：h-BN-SiC ceramic composites with different SiC contents were fabricated by spark plasma sintering. The results indicate that the addition of hard SiC particles has a remarkable effect on the densification, microstructure, mechanical properties and thermal shock resistance of the composites. Compared with pure h-BN ceramic, the relative density and mechanical properties of h-BN-SiC ceramic composites were improved obviously. The optimal properties of h-BN-SiC ceramic composites were obtained at SiC content of 25%, and the relative density, flexural strength and fracture toughness reached 97.8%, 289.2 MPa and 3.45 MPa m(1/2), respectively. Moreover, the relationship of fracture toughness and fracture mode was discussed. The thermal shock test results showed that the h-BN-SiC ceramic composite with the SiC content of 25% exhibited excellent thermal shock resistance, presenting critical temperature difference up to 900 degrees C. The high temperature oxidation of h-BN and SiC on material surface led to the formation of borosilicate glass phase, which could heal the surface microcracks and then improve the thermal shock resistance.