Post-processing to Modify the α Phase Micro-Texture and β Phase Grain Morphology in Ti-6Al-4V Fabricated by Powder Bed Electron Beam Melting

Additively manufactured Ti-6Al-4V has columnar β grains along the build direction with a 〈001〉 fiber texture. Because of Burgers Orientation Relationship, the resulting α phase becomes textured albeit less strongly than the β phase. Microtexture zones have been identified in the α phase in laser-based systems. There have been limited studies on α phase texture and its impact on mechanical behavior of Ti-6Al-4V fabricated via electron beam melting (EBM) powder bed additive manufacturing along with the use of super-transus heat treatments to modify the resulting α phase texture. We present the role of texture on influencing the tensile behavior of EBM Ti-6Al-4V. We observed that super-transus heat treatment of the alloy also results in columnar to equiaxed transition of β grains with a subsequent change in α phase texture. Potential mechanisms for the formation of equiaxed β are discussed.