|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Additive Manufacturing: Building the Pathway towards Process and Material Qualification
||Revealing Martensite Decomposition in Ti-6Al-4V Alloys Additively Manufactured with Electron Beam Melting by X-ray and Neutron Diffraction
||Kenta Yamanaka, Manami Mori, Yusuke Onuki, Shigeo Sato, Akihiko Chiba
|On-Site Speaker (Planned)
The microstructural evolution of Ti-6Al-4V alloys during electron beam melting (EBM) was examined. The as-built microstructure was principally characterized by a β (bcc) → α’ (hcp) martensitic transformation that occurred during the EBM procedure. The α’-martensite was subsequently tempered due to the high process temperature as high as the preheating temperature. However, X-ray diffraction line-profile analysis revealed the alloy specimens have relatively high dislocation densities, contributing to the overall strength. The film-like β-phase precipitated simultaneously at the interfaces of the α’ martensite laths. We successfully determined the β-phase fraction, which is generally difficult to evaluate quantitatively, using Rietveld texture analysis based on time-of-flight neutron diffraction measurements. The overall texture evolution was characterized by the martensitic transformation and did not vary during the EBM procedure. It was also found with this technique that the β-phase had the Burgers orientation relationship with the α’-martensite matrix.
||Planned: Supplemental Proceedings volume