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

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Vol. 50; no. 7; pp. 3429 - 3439
• Main Authors: Nandwana, Peeyush, Lee, Yousub, Ranger, Chasen, Rollett, Anthony D., Dehoff, Ryan R., Babu, Sudarsanam S.
• Format: Journal Article
• Language: English
• Published: New York Springer US 15.07.2019; Springer Nature B.V; ASM International
• Subjects: Additive Manufacturing; Beta phase; Characterization and Evaluation of Materials; Chemistry and Materials Science; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Electron beam melting; Heat treating; Heat treatment; Laser applications; Martensite Decomposition; Materials Science; Mechanical properties; Metallic Materials; Microtexture; Morphology; Nanotechnology; Phase; Phase transitions; Post-processing; Powder beds; Structural Materials; Surfaces and Interfaces; Texture; Thin Films; Ti-6Al-4V; Titanium base alloys; Transformation
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-019-05247-4

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.