多孔硼化锆–碳化硅–石墨超高温陶瓷的抗热冲击性能  

Thermal Shock Resistance of Porous ZrB2–SiC–Graphite Ultrahigh-Temperature Ceramics

作　　者：王帅[1] 金鑫鑫[1] 董丽敏[1,2] 吴可嘉 陈乐[1] WANG Shuai;JIN Xinxin;DONG Limin;WU Kejia;CHEN Le(Harbin University of Science and Technology,School of Materials Science and Engineering,Harbin 150040,China;Harbin University of Science and Technology,Key Laboratory of Engineering Dielectrics and Its Application,Harbin 150080,China)

机构地区：[1]哈尔滨理工大学材料科学与工程学院,哈尔滨150040 [2]哈尔滨理工大学工程电介质及其应用教育部重点实验室,哈尔滨150080

出　　处：《硅酸盐学报》2018年第6期766-771,共6页Journal of The Chinese Ceramic Society

基　　金：国家青年科学基金(51602082);黑龙江省普通本科高等学校青年创新人才培养计划(UNPYSCT–2017083)资助

摘　　要：为了改善ZrB2基超高温陶瓷的热冲击损伤抗性,采用冷等静压–无压烧结法在ZrB2–SiC–Graphite（ZSG）材料体系中引入孔隙制备ZSG多孔陶瓷,同时利用热压法制备了ZSG致密陶瓷作为对比材料,研究了2种ZSG陶瓷材料的力学性能,并探究了孔的引入对ZSG复合陶瓷热冲击性能的影响。结果表明：孔的引入降低了ZSG陶瓷的抗弯强度（由230.04 MPa降为98.12 MPa）和断裂韧性（由4.69 MPa·m^1/2降为4.27 MPa·m^1/2）,但孔的引入大大提升了ZSG陶瓷的临界裂纹尺寸（由132μm增长为602μm）。孔的引入明显提高了材料的残余强度保持率（由54%增长为84%）,即改善了ZrB2基陶瓷的热冲击损伤抗性。与其它材料体系不同的是,孔的引入还提高了ZSG复合陶瓷的临界温差,说明孔对ZSG复合陶瓷的热冲击断裂抗性和损伤抗性具有同时增强的效果。Pores were introduced into porous ZrB2–SiC–Graphite（ZSG） ceramics by a cold isostatic pressing pressureless sintering method in order to improve the thermal shock damage resistance of ZrB2 based ultrahigh-temperature ceramics. Also, dense ZSG ceramics were prepared by a hot pressing method. The mechanical properties of these two kinds of ZSG ceramic materials were compared. The effect of pores introduction on the thermal shock resistance of ZSG ceramic was also investigated. The result shows that the introduction of pores reduces the flexural strength（i.e., from 230.04 to 98.12 MPa） and fracture toughness（i.e., from 4.69 to 4.27 MPa·m^1/2） of ZSG ceramics. However, the introduction of pores greatly increases the critical crack size（i.e., from 132 to 602 μm） of ZSG ceramic. Moreover, the pores introduction improves the residual strength retention rate（i.e., from 54% to 84%）, which increases the thermal shock damage resistance of ZrB2 based ceramics. Unlike other materials, pores also increase the critical temperature difference of ZSG ceramic. The pores introduction can improve the thermal shock fracture resistance and damage resistance of ZSG ceramic simultaneously.

关 键 词：硼化锆–碳化硅–石墨 力学性能 热冲击损伤抗性 热冲击断裂抗性 

分 类 号：TQ174[化学工程—陶瓷工业]