关键词: 六铝酸钙, 预烧温度, 二步烧结法, 致密度, 线收缩率, 常温耐压强度

Abstract: CA₆ materials were prepared by the two-step sintering method using alumina and calcium carbonate as raw materials,prefiring,crushing,press shaping,and high temperature sintering.Effects of prefiring temperatures (1 100,1 200,1 300,and 1 400 ℃) on the properties and the microstructure of CA₆ materials were mainly studied.The results show that:(1)preheating and crushing damage partial pores in the materials and reduce the pore formation during high temperature sintering,the prepared CA₆ material performs higher density and cold compressive strength than the CA₆ material prepared by the conventional sintering process;(2)the optimum prefiring temperature is 1 200 ℃;the prepared CA₆ material has the apparent porosity of 28.2%,the bulk density of 2.52 g·cm^-3,and the cold compressive strength of 330 MPa.

Key words: calcium hexaluminate, prefiring temperature, two-step sintering, density, linear shrinkage, cold compressive strength