原位引入BN-SiC燃烧合成Si_(3)N_(4)-BN-SiC复合材料  

Combustion Synthesis of Si_(3)N_(4)-BN-SiC Composites by in-situ Introduction of BN and SiC

作　　者：张叶 姚冬旭[1] 左开慧[1] 夏咏锋[1] 尹金伟[1] 曾宇平[1] ZHANG Ye;YAO Dongxu;ZUO Kaihui;XIA Yongfeng;YIN Jinwei;ZENG Yuping(State Key Laboratory of High Performance Ceramics and Superfine Microstructure,Shanghai Institute of Ceramics,Chinese Academy of Sciences,Shanghai 200050,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院上海硅酸盐研究所,高性能陶瓷和超微结构国家重点实验室,上海200050 [2]中国科学院大学,材料科学与光电工程中心,北京100049

出　　处：《无机材料学报》2022年第5期574-578,共5页Journal of Inorganic Materials

基　　金：National Key R&D Program of China(2018YFF01013605);National Natural Science Foundation of China(51902327)。

摘　　要：Si_(3)N_(4)-BN-SiC复合材料以其良好的力学性能和抗氧化性能而具有良好的工程应用前景。本研究以Si、Si_(3)N_(4)稀释剂、B_(4)C和Y_(2)O_(3)为原料,采用燃烧合成法成功制备了Si_(3)N_(4)-BN-SiC复合材料。通过Si、B_(4)C和N_(2)气之间的反应,在Si_(3)N_(4)陶瓷中原位引入BN和SiC,制备的Si_(3)N_(4)-BN-SiC复合材料由长棒状的β-Si_(3)N_(4)和空心球形复合材料组成。实验研究了空心球微结构的形成机理,结果表明,生成的SiC、BN颗粒及玻璃相覆盖在原料颗粒上,当原料颗粒反应完全时,形成空心球形微结构。并进一步研究了B4C含量对Si_(3)N_(4)-BN-SiC复合材料力学性能的影响。原位引入SiC和BN在一定程度上可以提高复合材料的力学性能。当B_(4)C添加量为质量分数0~20%时,获得了抗弯强度为28~144 MPa、断裂韧性为0.6~2.3MPa·m^(1/2),杨氏模量为17.4~54.5GPa,孔隙率为37.7%~51.8%的Si_(3)N_(4)-BN-SiC复合材料。Si_(3)N_(4)-BN-SiC composites present desirable potential for engineering applications because of their improved mechanical properties and oxidation resistance.In present work,Si_(3)N_(4)-BN-SiC composites were successfully fabricated by combustion synthesis using Si,Si_(3)N_(4)diluent,B_(4)C,and Y_(2)O_(3)as initial powders.BN and SiC were in situ introduced into Si_(3)N_(4)ceramics by the reaction between Si,B_(4)C,and N_(2)gas.The obtained Si_(3)N_(4)-BN-SiC composites were composed of elongatedβ-Si_(3)N_(4)matrix and hollow spherical composites.The formation mechanism of the hollow spherical microstructure was investigated.The results show that the generated SiC and BN particles and glass phase cover on the raw materials,and hollow spherical microstructure is formed when raw particles are depleted.Furthermore,the impacts of B_(4)C content on the mechanical properties of Si_(3)N_(4)-BN-SiC composites were investigated in detail.The in-situ introduction of BN and SiC is beneficial to improving mechanical properties of the composites to some extent.Finally,Si_(3)N_(4)-BN-SiC composites with bending strength of 28–144 MPa,fracture toughness of 0.6–2.3 MPa·m^(1/2),Young’s modulus of 17.4–54.5 GPa,and porosity of 37.7%–51.8%were obtained for the samples with 0–20%(in mass)B_(4)C addition.

关 键 词：燃烧合成 Si_(3)N_(4)-BN-SiC复合材料 原位引入 相组成 空心球 形成机理 

分 类 号：TQ174[化学工程—陶瓷工业]