热压反应合成 TiAl 合金的密度及孔隙分布

DENSIFICATION AND POROSITY DISTRIBUTION OF TiAl BASED ALLOY PREPARED BY REACTIVE HOT PRESSING

采用Ｔｉ，Ａｌ混合元素粉，通过热压反应合成方法，研究了热压温度对Ｔｉ－４８Ａｌ（原子数分数）致密化行为和孔隙分布的影响．结果表明：随着热压温度的升高，制备的材料致密度升高，而在１４００℃下，由于晶粒粗大，导致材料的致密度难以继续提高，冷压坯上密度的不均匀性直接影响热压坯中材料的孔隙分布；提高冷压坯的密度。

Blended elemental Ti 48Al(atom number fraction,%) powders were hot pressed at various temperatures, and their densification behavior and porosity distribution were discussed in this article. Results show that material density increases as the hot pressing temperature goes up, but the densification process is hindered at 1400 ℃,owing to the coarsening of grains. The inhomogeneity of density distribution in compacts will affect the porosity distribution in hot pressed samples; increasing the compact density will increase the density of hot pressed samples to a certain extent.