TiO_2在Al_2O_3-ZrO_2电熔料共晶体中的固溶行为

SOLID SOLUTION BEHAVIOR OF TiO_(2) IN Al_(2)O_(3)-ZrO_2 EUTECTIC OF FUSED CORUNDUM-ZIRCONIA

用扫描电镜对含25%(质量分数)ZrO2和适量TiO2的电熔锆刚玉的显微结构分析表明:这种电熔料的显微结构由等粒状初晶刚玉和刚玉ZrO2共晶组成。能量散射X射线分析结果表明:TiO2固溶于共晶体的ZrO2中而不溶于刚玉。TiO2在共晶体ZrO2中的固溶度为10%左右。此现象可由TiO2ZrO2系相图具有很大的ZrO2固溶相区和结晶学中有关离子半径和电价匹配的原理而得以解释。

The microstructure of fused zirconia- corundum material containing 25% ZrO2 in mass and some TiO2 was characterized by scanning electron microscope and energy dispersive X-ray analysis. The results indicate that the microstructure of such material is formed primarily by crystallization of equa-granular corundum and corundum- zirconia （C＋Z） eutectic. TiO2 is solid soluble in ZrO2 grains in the （C＋Z） eutectic, but is not soluble in corundum. The solid solubility of TiO2 in ZrO2 is around 10%. This phenomenon can be interpreted by the fact that a large primary phase region of the ZrO2 solid solution phase exists in the diagram of the TiO2-ZrO2 system and by the principles of crystallography related to the ionic radius and valence compatibilities.