AI_2O_3-TiC系陶瓷材料的组织结构

Microstructures of Al_2O_3-TiC Ceramic Materials

用扫描和透射电镜研究了Al_2O_3-TiC系陶瓷材料的成分、断口形貌和精细结构。结果表明,陶瓷体足由Al_2O_3、TiC和金属粘结相组成。断口形貌为两类骨架结构相互穿插结合,各相致密,其颗粒大小在0.5～1.0μm。有些颗粒和晶粒内部有细微亚晶粒,尺度在0.1～0.3μm左右。硬度测定指示,材料的维氏和洛氏硬度值分别为2400HV和HRA93.70。根据压痕法测得的压痕裂纹长度和硬度值参数,计算其K_(IC)为5.86MPam^(1/2)。

The compositions, morphologies and fine structure of Al_2O_3-TiC ceramic materials were analysed by SEM and TEM. The results show that the fracture morphology of the ceramic materials consists of two kinds of framework-structures, which alternate each other. Each phase in ceramics materials is fine. The particle size is about 0.5～1.0μm. The demension of substructures in grains and some particles is about 0.1～0.3μm. The handness of the materials is 2400HV and HRA 93.7, respectively. The fracture toughness K_IC calculated by the crack length of impression and hardness parameters is 5.86MPam^(1/2).