CaH2还原TiO2制备TiAl合金粉的研究

在1 112～1 600K温度范围内,以TiO2粉、CaH2粉和Al粉为原料,采用还原扩散法制备TiAl合金粉.该法是一种低成本高效率的绿色冶金方法.通过分析Ca-TiO2-Al体系可能发生的反应,计算这些反应的吉布斯自由能和体系的Ca蒸气压,以及对原料配比的控制,从热力学角度上证实了采用还原扩散法制备TiAl合金粉是可能的.在1 423 K条件下,针对保温时间进行了一系列实验.并对保温8 h的实验产物进行XRD分析,证实为TiAl合金粉.

RESEARCH OF PRODUCING TiAl ALLOY POWDER WITH CaH2 REDUCTION TiO2

In the temperature range from 1 112 K to 1 600 K,the TiAl alloy powder can be obtained by the Reduction-Diffusion Method using TiO_2 powder,CaH_2 powder and the Al powder as raw materials.And this method is a green metallurgy method of low cost and high efficiency.Considering the possible reactions in Ca-TiO_2-Al system,according to calculated Gibbs free energy and vapor pressure of Ca,and controlling the proper reactant proportioning the thermodynamical feasibility of obtaining TiAl alloy powder by reduction-diffusion method was identified.A series of experiments were performed at 1 423 K for different holding time.By XRD,the product obtained by holding for 8 h was confirmed to be the TiAl alloy powder.