莫来石/钛酸铝层状复合材料的制备

Fabrication of mullite/aluminum titanate laminated composites

采用轧膜成型和热压烧结工艺,以莫来石为基体层,钛酸铝为界面分隔层制备了陶瓷基层状复合材料,研究了层状复合材料的力学性能、显微结构、应力应变行为和断裂机制。结果表明,利用钛酸铝强度低的特点,以此作为陶瓷基层状复合材料的界面分隔层是可行的。与块体莫来石陶瓷相比,复合材料的强度有所降低,但断裂韧性提高;断口形貌观察和分析表明莫来石/钛酸铝层状复合材料在界面区域发生裂纹偏转,表现为非脆性断裂。

Mullite/aluminum titanate laminated composites were fabricated using mullite as matrix and aluminum titanate as interphases by means of rolling and hot-pressing sintering method. The mechanical properties, microstructure, the behavior of stress-strain and fracture mechanism of the laminated composites were investigated. The results showed that it was feasible to use aluminum titanate as a weak interphase in laminated composites because of its lower strength. Mullite/aluminum titanate laminated composites had lower bending strength and higher fracture toughness when compared with bulk mullite ceramic. Crack deflection occurred at the interlayer between mullite matrix and aluminum titanate interphase or within aluminum titanate interphase. Mullite/aluminum titanate laminated composites had a characteristic of non-brittle fracture.