【摘要】 采用含乙烯基聚硅氮烷为原料,利用先驱体转化法与有机泡沫浸渍法相结合制备SiCN泡沫陶瓷。通过聚氨酯泡沫及聚硅氮烷的热分析制定温度曲线,研究了裂解温度、浸渍/裂解增强处理次数等工艺参数对泡沫陶瓷抗压强度的影响,采用XRD、SEM及EDS对SiCN泡沫陶瓷进行了物相、微观结构及成分分析。结果表明,在1000-1400℃温度范围内,随着温度的升高,泡沫陶瓷的抗压强度先升高后降低,增强处理对提高抗压强度有明显效果,当裂解温度为1300℃,经二次增强处理后,试样的抗压强度达11.5MPa。XRD研究表明,随着温度的逐步升高,聚硅氮烷的裂解产物发生了由非晶态向晶态的转变。微观结构分析显示,SiCN泡沫陶瓷呈三维网状结构,具有良好的贯通性,开孔气孔率达到85%。更多还原

【Abstract】 The foam SiCN ceramic was prepared using the polyurethane sponge and polysilazane as raw materials.It was found the compression strength of the foam ceramic was affected by the processing parameters including the pyrolysis temperature and the number of times of reinforcement treatment.XRD analysis reveals that the polysilazane has transformed into an amorphous SiCN ceramic at 1100-1300℃.The amorphous SiCN ceramic transforms into crystal SiC and Si3N4 at 1400℃.The maximum compression strength of 11.5 MPa was obtained at the pyrolysis temperature of 1300℃.The reinforcement treatment can remarkably increase the compression strength of foam ceramic.Microstructure study reveals that the foam SiCN ceramic have an open,uniform and interconnected porous structure with a pore size of 100-500 μm and high porosity of 85%.更多还原