溶胶-凝胶法制备氮化硅陶瓷微球

Preparation of Silicon Nitride Ceramic Microspheres with Sol-gel Method

氮化硅陶瓷是一种性能优良的高温结构陶瓷,其陶瓷微球有广泛的工业应用前景,本研究以锆溶胶为凝胶剂,纳米硅粉为硅源,利用内凝胶法制备了氮化硅陶瓷微球。在制备氮化硅凝胶球过程中,锆溶胶充当凝胶剂。在烧结过程中,氧化锆能够促进氮化硅陶瓷微球致密化。探究了胶液配方中ZrO^(2+)和HNO_(3)浓度对胶液稳定性的影响;洗涤工艺对氮化反应的影响;烧结温度对凝胶球氮化率的影响。在氮化温度为1450℃、氮化时间为4 h的烧结工艺下制备得到了氮化率达80%的氮化硅陶瓷微球。

Silicon nitride ceramics have excellent performance at high temperatures.Silicon nitride ceramic microspheres have a wide range of industrial applications.In this study,zirconium sol was used as a gel additive and nano-silica powder was used as a silicon source,to prepare silicon nitride ceramic microspheres.The zirconium sol acted as a gelling agent during the formation of the gel balls,while the zirconium oxide promoted the densification of silicon nitride ceramic microspheres during the sintering process.The influences of the concentration of ZrO^(2+)and HNO_(3)in the glue formulation on stability of the glue,the washing process on the nitridation reaction and the sintering temperature on the nitridation rate of the gel ball were studied.Finally,silicon nitride ceramic microspheres with a nitriding rate of 80%were obtained after sintering at nitriding temperature of 1450℃for 4 h.