Microstructure Control and Tensile Properties of EBM γ-TiAl
CHEN Wei1,2, YANG Yang2, LIU Liangliang3, CHEN Zheyuan2, LIU Dong3
(1. Materials Application Department, AVIC Manufacturing Technology Research Institute, Beijing 100024, China;
2. Power Beam Processing Laboratory, Beijing 100024, China;
3. Institute of Metal Research, Chineses Academy of Sciences, Shenyang 110016, China)
Abstract：The microstructure evolution and tensile properties of electron beam selective melted Ti-48Al-2Cr-2Nb alloy
were studied. The Al loss caused an inhomogeneous microstructure. The as-build material is composed of large γ grains
and small γ grains pinned by a chain-like α2 grains. The γ phase occupies 89% of the material volume and exhibits a weak
texture, but the α2 phase exhibits a 14.1 times random (0001) texture with its c axis parallel to the build direction. The room
temperature tensile strength of the as-build material is 503MPa but the ductility is 0. HIP and heat treatment lowered the
tensile strength but improved ductility by a large extent. Up until 800℃ , the TiAl-4822 with a duplex microstructure exhibits
tensile strength higher than 460MPa; while the TiAl-4822 with a fully lamella microstructure exhibits tensile strength
higher than 400MPa.
2017, 
