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

摘要： 为提高锆酸钙材料的致密度,以碳酸钙和氧化锆为原料,采用预烧—破碎—压制成型—高温烧成的二步烧结法制备了锆酸钙(CaZrO₃)材料,主要研究预烧温度(分别为1 200、1 300、1 400、1 500 ℃)对CaZrO₃材料显微结构和常温性能的影响。结果表明:1)采取二步烧结法能使原料分布均匀,反应彻底,避免了氧化锆相变导致的试样膨胀开裂;2)预烧温度为1 400 ℃时,试样的综合性能最优,主晶相CaZrO₃可达99%(w),平均晶粒尺寸为4~5 μm,显气孔率为1.6%,体积密度为4.40 g·cm^-3,常温耐压强度为590 MPa。

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