选区激光熔化及热等静压制备Ti-25Ta合金微观组织和力学性能

Microstructure Evolution and Mechanical Properties of Ti-25Ta Alloy Fabricated by Selective Laser Melting and Hot Isostatic Pressing

摘要:

采用选区激光熔化技术制备了Ti-25Ta合金样品，并对打印件和热等静压样品的相对密度、显微组织、显微硬度和拉伸性能进行了表征。结果表明，随着激光功率的增加，扫描轨迹宽度和深度增加，表面形貌得到改善。经热等静压处理后，样品最大致密度由95.31%提高到98.01%。同时，随着输入功率的增加，晶粒细化为板条马氏体和胞状晶粒。致密化处理后，亚晶粒合并，并形成大角度晶界。热等静压稳定了合金的显微硬度，提高了合金的抗拉伸强度和伸长率。

Abstract:

Ti-25Ta alloy samples were fabricated by selective laser melting, and the relative density, microstructure, microhardness and tensile properties of the as-built and hot isostatic pressing (HIP)-prepared samples were characterized. Results show that the track width and penetration depth are increased with the increase in laser power, and the surface morphology is improved. The maximum relative density improves from 95.31% to 98.01% after HIP process. Moreover, the microstructure is refined into the lath martensite and cellular grains with the increase in input power. After densification treatment, the subgrain coalescence occurs and high angle grain boundaries are formed. In addition, HIP process stabilizes the microhardness and enhances the tensile strength and elongation.