SiC晶须补强ZTA（Y）陶瓷基复合材料的研究

STUDY ON SIC-WHISKER REINFORCED ZTA(Y)CERAMIC MATRIX COMPOSITES

本文将高强、高模量的ＳｉＣ晶须引入以Ｙ２Ｏ３稳定的ＺｒＯ２（ｔ）相变增韧Ａｌ２Ｏ３基陶瓷材料［即ＺＴＡ（Ｙ）］中．研究了不同晶须含量对复合材料的抗弯强度和断裂韧性的影响．实验结果表明，ＳｉＣ晶须能明显提高ＺＴＡ（Ｙ）陶瓷基复合材料的强度和韧性，体积含量为２０％的ＳｉＣ晶须的复合材料性能可达：σｂｂ＝８３０ＭＰａ，Ｋｉｃ＝９．８ＭＰａｍ１／２．通过与ＳｉＣｗ／Ａｌ２Ｏ３复合材料系统的比较分析，认为ＳｉＣｗ／ＺＴＡ（Ｙ）复合材料中，由于热膨胀系数差异所产生的基体中的张应力可由诱导ＺｒＯ２（ｔ）的马氏体相变来缓解。

The flexcure strensth and fracture of the composites influendo by SiC whisker volume content are studied.The experiment shows that SiC whisker can obviously incerase the strength and toughnes of ZTA(Y) ceramic matrix competes. For the optimum procese,a 20% SiC-whisker Y-ZTA matrix composites exhibits a fiexure strength 830MPa, a fracture toughness 9. 8MPam1/2. Compared with Al2O3 matrix composites reinforced by SiC-whisker; it is found that the tensile sterss cause by the difference of thermal expansion coefficient between whisker and mains can be refaxed by ZrO2(t)martesitic phase transformation. In the SiC-whisker/ZAT(Y)composite System, phase transformation toughening and whisker reinforcemend may contribute to fractura toughness.