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

Abstract: In order to improve their density,calcium zirconate (CaZrO₃) materials were prepared with calcium carbonate and zirconia as raw materials by the two-step sintering method:pre-firing—crushing—pressing—high temperature sintering.The effects of the pre-firing temperature (1 200,1 300,1 400,and 1 500 ℃) on the microstructure and cold properties of the CaZrO₃ materials were studied.The results show that:(1)the two-step sintering method can make the distribution of raw materials uniform and the reaction thorough,and avoid the expansion cracking of the sample caused by zirconia phase transformation;(2)when the pre-firing temperature is 1 400 ℃,the sample has the optimal comprehensive properties:the main crystalline phase CaZrO₃ reaches 99 mass%,the average grain size is 4-5 μm,the apparent porosity is 1.6%,the bulk density is 4.40 g·cm^-3,and the cold compressive strength is 590 MPa.

Key words: calcium zirconate, pre-firing temperature, two-step sintering method, density, linear shrinkage rate, cold compressive strength