选区激光熔化制备钛铝合金研究进展

RESEARCH PROGRESS OF SELECTIVE LASER MELTING TITANIUM ALUMINIDE ALLOY

摘要:

钛铝合金具有密度小、比强度高、耐高温、抗蠕变、抗氧化等优点,可以很好地满足航空发动机涡轮叶片的高温应用环境,是近年新金属材料研究的一大热点。然而钛铝合金冷热加工成形困难,严重限制着其规模化应用。选区激光熔化(SLM)具有加工速度快、成形精度高、近净成形等优点,有望用以实现高性能钛铝合金的一体化成形制备,进而推动钛铝合金的规模化应用。本文综述了近年来国内外关于SLM钛铝合金制备技术的研究进展,系统评述了粉末成分及形貌、成形工艺参数和成形后热处理对SLM钛铝合金的缺陷、相组成、微观组织和力学性能的影响,并展望了SLM钛铝合金的未来发展方向。

Abstract:

Owing to its high specific strength, creep resistance, oxidation resistance and low density, titanium aluminide alloy (TiAl) is regarded as an ideal candidate material to replace nickel-based superalloys for the fabrication of engine turbine blades used in aerospace applications. However, its application is restricted by the poor plasticity at room temperature and difficulties in hot shaping. Comparing with conventional subtractive manufacturing process, selective laser melting possesses some unique advantages such as short lead time, high processing resolution, near-net shape forming, etc. Therefore, it can be used to remedy the deficiency of conventional subtractive manufacturing process and accelerate the application of TiAl. This paper summarized the research progress of titanium aluminide manufactured by selective laser melting at home and abroad. The effect of chemical composition, powder morphology, printing parameters and post-printing heat treatment on the printing defects, phase constitutes, microstructure and mechanical properties were reviewed comprehensively. Finally, we outlooked the future developing directions of SLM TiAl.