Abstract: Calcium zirconate material is a crucible material for high temperature alloy melting with potential application prospects.The crucibles with dimensions of 30 mm×7 mm were prepared using fused calcium zirconate (CaZrO₃) as the main raw material,adding a small amount (0.5%-2%,by mass) of TiO₂,Al₂O₃,La₂O₃,CeO₂,and Y₂O₃ powders as the sintering agents,pressing under 150 MPa,and sintering at 1 650 ℃ for 3 h.Effects of the type and addition of sintering agents on the sintering degree,phase composition and microstructure of calcium zirconate materials were studied.The results show that:(1)the sintering performance of the sample with 2% TiO₂ is the best because the sintering of the material is promoted due to the solid solution reaction;(2)the suitable addition of Al₂O₃ is 1% because the formed liquid phase promotes the sintering of the material and the average grain size in the sample after sintering is 10-30 μm;(3)the suitable addition of Y₂O₃ is 0.5% because the solid solution reaction promotes the material sintering and the average grain size in the sample after sintering is 10-50 μm.

Key words: calcium zirconate, sintering agent, relative density, grain size

摘要： 锆酸钙材料是一种具有潜在应用前景的高温合金熔炼用坩埚材料,以电熔锆酸钙(CaZrO₃)为主原料,添加少量(加入质量分数为0.5%~2.0%)的TiO₂、Al₂O₃、La₂O₃、CeO₂、Y₂O₃粉体作为烧结助剂,在150 MPa下压制成30 mm×7 mm的坯体,经1 650 ℃保温3 h烧成。研究了烧结助剂种类及其加入量对锆酸钙材料烧结程度、物相组成及显微结构的影响。结果表明:1)添加2%(w)TiO₂时试样烧结性能最优,这是由于发生固溶反应促进了材料的烧结;2)Al₂O₃的加入量为1%(w)较适宜,由于产生液相促进了材料的烧结,烧后试样中平均晶粒尺寸为 10~30 μm;3)Y₂O₃的加入量为0.5%(w)较适宜,由于发生固溶反应促进了材料的烧结,烧后试样中平均晶粒尺寸为10~50 μm。

关键词: 锆酸钙, 烧结助剂, 相对密度, 晶粒尺寸