【摘要】 采用等离子电弧双丝增材制造技术成功制备了Ti-48Al合金(at.%)，并对其沉积态和热处理后的组织特征进行了系统地研究.结果表明，沉积态Ti-48Al合金主要由α2相和γ相组成，沿着沉积方向，沉积态组织呈现由树枝晶区和片层晶团区交替分布的不均匀性特征，并且在树枝晶区存在严重的枝晶间Al元素偏析现象.在1 340℃/10 h/炉冷热处理后，不均匀的沉积态组织转变为晶粒尺寸细小的双态组织，Ti-48Al合金的微观组织的不均匀性获得明显改善，并且α2相含量显著增加，组织的择优取向减弱.更多还原

【Abstract】 Ti-48Al alloy is fabricated successfully using plasma arc powred twin wire-directed energy deposition-arc,and its microstructure characteristic before and after heat treatment is systematically investigated.The results show that asdeposited Ti-48Al alloy consists of α2 and γ phase.The microstructure is characterized by the alternatively distributed dendritic grain and fully lamellar colony along the building direction for as-deposited Ti-48Al alloy,and there is interdendritic Al element segregation in the dendritic grain region.After heat treatment in 1 340℃/10 h/furnace cooling,the duplex microstructure with fine grain size is obtained,and the microstructure heterogeneity is significantly improved,the α2 phase content is obviously increased,the preferred orientation of microstructure is also weakened.更多还原