NiO催化氮化制备Si3N4/SiC复合材料及其高温性能  

Preparation and High Temperature Properties of Si3N4/SiC Composites by Catalytic Nitridation Method Using NiO as Catalyst

作　　者：张俊[1] 刘江昊[1] 赵万国 韩磊[1] 古亚军[1] 张海军[1] ZHANG Jun, LIU Jianghao, ZHAO Wanguo, HAN Lei, GU Yajun, ZHANG Haijun(The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, Chin)

机构地区：[1]武汉科技大学省部共建耐火材料与冶金国家重点实验室

出　　处：《硅酸盐学报》2018年第3期333-340,共8页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金面上项目(51472185,51472184);湖北省教育厅高等学校优秀中青年科技创新团队计划(T20162);湖北省自然科学基金创新群体项目(2017CFA004)

摘　　要：以原位生成的NiO纳米颗粒为催化剂,采用催化氮化的方法制备Si3N4/SiC复合材料,研究了所制备复合材料的常温物理性能、高温力学性能、抗热震性、抗氧化及抗冰晶石侵蚀性能。结果表明：1）所制备Si3N4/SiC复合材料的常温耐压强度及抗折强度值分别为131.0及24.6 MPa;2）Si3N4/SiC复合材料的高温抗折强度随着温度的升高而增加,1 573 K时达到最大值后又缓慢下降,但即使1 673 K时复合材料的高温抗折强度仍高于其常温抗折强度;3）Si3N4/SiC复合材料具有较好的抗热震性能,当实验温度为1 573 K,采用水冷时,其强度保持率仍有50%左右;4）所制备Si3N4/SiC复合材料开始氧化温度约为1 173 K,其抗氧化性能优于无催化剂时制备的Si3N4/SiC复合材料;5）所制备的复合材料具有良好的抗冰晶石侵蚀性能。由于Ni O纳米颗粒催化生成大量的Si3N4晶须,这些晶须交互分布在骨料之间,形成网络状结构,从而提高了复合材料的性能。Si3N4/SiC composites were prepared by a catalytic nitridation method using in situ formed NiO nanoparticles （NPs） as a catalyst. The room-temperature and high-temperature mechanical properties of the as-prepared composites were investigated. The results show that the as-prepared Si3N4/SiC composite has the maximum cold compression strength （accs） of 131.0 MPa and modulus of rupture （aMOR） of 24.6 MPa with NiO NPs as a catalyst. The high-temperature MOR （aHMOR） of the as-prepared composite firstly increases and then decreases with the increase of the temperature. The maximum σHMOR is obtained at 1 573 K. The σHMOR of the as-prepared composite even at 1 673 K is still greater than that of the composite at room temperature. The residual strength holding ratio of the as-prepared composites is approximately 50% at 1 573 K, indicating that the prepared Si3N4/SiC composite has the superior thermal shock resistance. The initial oxidation temperature of the prepared composite is 1 173 K, and the oxidation resistance of Si3N4/SiC composite prepared with NiO nanoparticle catalyst is greater than that of the sample without catalyst. The prepared composite has a weU resistance to cryolite corrosion. The formation of Si3N4 whiskers with NiO nanoparticles catalyst is promoted, and the Si3N4 whiskers is distributed in aggregates to form a network-like structure, so that the performance of composite material is improved.

关 键 词：氮化硅结合碳化硅复合材料 催化氮化 碳化硅晶须 高温性能 

分 类 号：TB35[一般工业技术—材料科学与工程]