Al2O3基复合材料中纳米SiC对微观结构的影响

本文从烧结温度、基体晶粒大小、断裂方式、SiC在基体中的分布等几个方面研究了纳米SiC颗粒的加入对Al2O3微观结构的影响．用非均相沉淀工艺制备的纳米SiC-Al2O3复合粉体，具有Al2O3颗粒包裹纳米SiC的特点，提高了烧结温度，明显使Al2O3晶粒变小，并且抑制晶粒异常长大，试样的断裂方式从以沿晶断裂为主转变到以穿晶断裂为主．SiC在Al2O3中分布均匀，大部分位于晶粒内，少部分位于晶界上．这种微观结构有利于力学性能的提高．

Effect of Nano SiC Particles on the Microstructure of Al2O3 Ceramics

The hot-pressing temperature, matrix grain size, fracture mode and the distribution of SiCwere studied to reveal the effect of SiC inclusions on the microstructure of A12O3. A12O3-SiCcomposite powder was perpaxed by the precipitation method. Nano SiC pajrticajes were coatedwith Alaoa' After hot pressing, most of nano SiC particles were randomly located in A12O3 grains.SiC inclusions raised the hot~pressing temperature, decreased A12O3 grain size, and inhibited theabnormal grain growth of A12O3. The intergranular fracture for A12O3 was transformed to theilltragranular fracture for A12O3-SiC nanocomposites because of the addition of SiC. All thosemicrostructure changes would benefit the improvement of the mechanical properities of A12O3.