刚玉–Ti_(2)O_(3)共存物相在氧化气氛下的相变与形貌演变

Phase and Micromorphology Evolution of Corundum-Ti_(2)O_(3)Two-Phase Material in Oxidation Atmosphere

刚玉-Ti_(2)O_(3)共存物相是通过调整低钛铁的冶炼工艺得到的一种冶金副产品,其中Al2O3和Ti_(2)O_(3)两相独立存在,可以作为耐火材料原料使用。通过热重–差热结合热力学分析得知原料中的Ti_(2)O_(3)在700℃左右开始氧化反应,Al2O3和TiO2在1263℃左右开始反应,将原料在不同温度空气气氛下保温3 h烧成,由XRD结合SEM结果可知在800℃左右Ti_(2)O_(3)完成氧化反应,在1300℃受钛酸铝分解反应的影响,只有部分TiO2和Al2O3在刚玉交界处反应生成片状Al2Ti O5。随着烧成温度升高至1400℃和1500℃,Al2O3和TiO2生成Al2TiO5的反应逐渐完成,在片状的基础上生成了典型的柱状的钛酸铝。

Corundum-Ti_(2)O_(3)two-phase material is a by-product obtained via adjusting the smelting process of low-ferrotitanium alloy.Al2O3and Ti_(2)O_(3)exist independently in raw material,which can be used as a refractory raw material.According to the results by thermogravimetry-differential scanning calorimetry and thermodynamic analysis,the oxidation reaction of Ti_(2)O_(3)in the raw material starts at 700℃,and the reaction between Al2O3and TiO2starts at 1263℃.The results by X-ray diffraction and scanning electron microscopy indicate that Ti_(2)O_(3)completes the oxidation reaction at 800℃,which is affected by the decomposition reaction of Al2Ti O5at 1300℃,only part of TiO2and Al2O3reacts at the corundum junction to form flake Al2TiO5.As the sintering temperature is increased to 1400℃and 1500℃,the reaction of Al2O3and TiO2to form Al2TiO5is gradually completed,and a typical columnar aluminum titanate is formed on the basis of flakes.