氧化铝源对CA6多孔材料相组成和显微结构的影响

用Al(OH)₃、Al₂O₃微粉(uf-Al₂O₃)、工业Al₂O₃粉作为氧化铝源,CaCO₃为钙源,通过高温固相反应合成了六铝酸钙(CA₆)材料,研究了氧化铝原料对材料物相组成、显微结构和性能的影响。结果表明,以Al(OH)₃、Al₂O₃微粉、工业Al₂O₃为氧化铝源的试样在1 300 ℃时开始有CA₆相生成,各试样固相反应结束温度为1 500 ℃,继续提高烧成温度对物相组成没有影响。反应生成的CA₆显微形貌因氧化铝原料不同而不同,以Al(OH)₃为氧化铝源时,CA₆的显微形貌多为片状结构;以工业Al₂O₃为原料时,CA₆的显微形貌多为板片状和颗粒状;但以uf-Al₂O₃为氧化铝源时,CA₆的显微形貌则多为等轴状晶粒。以uf-Al₂O₃为氧化铝源时,制备的材料耐压强度和体积密度最高,气孔率最低;以Al(OH)₃为氧化铝源时,制备的材料耐压强度和体积密度最低,气孔率最高。

Influence of Alumina Source on Phase Composition and Microstructure of CA6 Porous Materials

CA₆ materials have been synthesized by high temperature solid state reaction using CaCO₃ as calcium source combined with Al(OH)₃, uf-Al₂O₃ and industrial Al₂O₃ as alumina sources. Effects of alumina sources on phase composition, microstructure and properties of CA₆ materials were studied. The results show that CA₆ forms at 1 300 ℃ using Al(OH)₃ and uf-Al₂O₃ as alumina sources. Solid state reaction temperature of samples finishes at 1 500 ℃. Further increasing of firing temperature has no effect on the phase composition. The microstructure of CA₆ produced by the reaction is changed with different alumina sources. When Al(OH)₃ is used as the alumia source, the microstructure of CA₆ is mostly platy. However, as used industrial Al₂O₃ as the alumia source, the microstructure of CA₆ is mostly plate-like and granular, but the microstructure of CA₆ is mostly equiaxed grains by using uf-Al₂O₃ as precursor. When used uf-Al₂O₃ as the source, the compressive strength and bulk density of the materials are the highest, and the porosity is the lowest. As used Al(OH)₃ as alumina source, the compressive strength and bulk density of the materials are the lowest, and the porosity is the highest.