磷酸盐结合法低温制备碳化硅泡沫陶瓷及其高温性能  

Preparation and High-temperature Properties of Silicon Carbide Foam Ceramics by Phosphate Bind Method at Low Temperature

作　　者：孙文飞[1,2,3] 刘卫[1,2,3] 黎阳[2,3] 

机构地区：[1]贵州大学材料与冶金学院,贵阳550025 [2]贵州师范大学材料与建筑工程学院,贵阳550025 [3]贵州省无机非金属功能材料重点实验室,贵阳550025

出　　处：《硅酸盐学报》2016年第9期1326-1332,共7页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(51462004);贵州省教育厅自然科学研究项目[黔教合KY字[2015](363)号]资助

摘　　要：以聚氨酯海绵为模板、磷酸二氢铝为黏结剂、碳化硅微粉为骨料,在800℃低温下制备出碳化硅泡沫陶瓷。研究了浆料中磷酸二氢铝含量、固相含量和高温处理对碳化硅泡沫陶瓷的线收缩率、体积密度、抗折强度、气孔率及微观形貌的影响,揭示了泡沫陶瓷在高温下结构及性能演变机理。结果表明:低温制备的碳化硅泡沫陶瓷线收缩率小于1%,线收缩率随固相含量的增加而减小,体积密度和抗折强度均随磷酸二氢铝和固相含量的增加而增大。低温制备的碳化硅泡沫陶瓷经高温处理后,其线收缩率、体积密度和抗折强度均随温度的升高先减小后增加,而气孔率则随温度的升高先增加后减小,处理温度为1 000℃时,碳化硅泡沫陶瓷抗折强度可达(2.06±0.10)MPa。碳化硅泡沫陶瓷低温下由A型和B型的Al(PO3)3将碳化硅微粉粘结起来,随着处理温度的升高,B型Al(PO3)3逐渐向A型转化,随着温度的进一步升高,A型Al(PO3)3逐渐分解成Al PO4相,将碳化硅微粉包裹、粘结起来。Silicon carbide foam ceramics were prepared at 800℃ with polyurethane sponge as a template, aluminum dihydrogen phosphate as a binder, silicon carbide powder as an aggregate. The effects of aluminum dihydrogen phosphate content, solid content and high-temperature treatment on the linear shrinkage, volume density, flexural strength, porosity and microstructure of the silicon carbide foam ceramics were investigated. The properties and structure evolution of the SiC foam ceramics treated at a high temperature were revealed. The results show that the linear shrinkage of the SiC foam ceramics is less than 1%, which gradually decreases with increasing the solid content. The volume density and flexural strength of the SiC foam ceramics increase with the increase of the aluminum dihydrogen phosphate and solid content. After the high-temperature treatment, the linear shrinkage, volume density and flexural strength of the SiC foam ceramics firstly decrease and then increase with increasing the temperature, and the open porosity firstly increases and then decreases. At the treatment temperature of 1000℃, the flexural strength is （2.06±0.10）MPa. The SiC foam ceramics are bindered by A-Al（PO3）3 and B-Al（PO3）3 at a low temperature. B-Al（PO3）3 gradually transforms to A-Al（PO3）3 when the treatment temperature increases, and A-Al（PO3）3 gradually breaks down into AlPO4 when the temperature further increases, resulting in the silicon carbide particles to be coated and bonded together.

关 键 词：磷酸二氢铝 碳化硅泡沫陶瓷 聚氨酯海绵 高温性能 

分 类 号：TQ174.12[化学工程—陶瓷工业]