氧化铝对锆酸钙材料组成和结构的影响

Effect of Al_2O_3 addition on composition and structure of CaZrO_3 synthesized from ZrO_2 and CaCO_3

以分析纯氧化锆和碳酸钙为原料,利用固相反应烧结制备锆酸钙。通过添加活性α-氧化铝,用X射线衍射、扫描电镜分析了氧化铝对锆酸钙材料相组成、晶胞参数、微观结构及致密度的影响。结果表明,利用碳酸钙和氧化锆在1600℃下保温1 h,制备出的锆酸钙材料致密度较低;氧化铝的加入导致锆酸钙相的晶胞参数和晶胞体积减小;Al3+的电场作用,减弱了锆酸钙中Ca-O的键力,导致锆酸钙材料中铝酸钙相增多。适量氧化铝促进锆酸钙的烧结,提高锆酸钙的致密度,确定氧化铝最佳加入摩尔百分含量为2%~3%。

CaZrO3 was prepared by solid reaction of raw materials of ZrO2 and CaCO3 with different content of Al2O3 as additive. The effect of Al2O3 addition on composition,microstructure and lattice parameters of crystalline phases in the materials was studied by XRD and SEM. The obtained results show that CaZrO3 can be synthesized from ZrO2 and CaCO3 at 1600 ℃ for 1 h by addition of Al2O3. The lattice parameters and unit cell volume of CaZrO3 decrease by the addition of Al2O3 in the reactants. The band of Ca-O weakens by the interaction of Al3 +with higher intensity of ionic field,which results in the formation and increasing of CaAl2O4 in the structure of CaZrO3. Through appropriate adding Al2O3,the density of the CaZrO3 is improved by the increase of its compactness. The appropriate addition of Al2O3 in the CaZrO3 is 2%-3% in molar fraction.