Solid/Powder Clad Ti-6Al-4V Alloy with Low Young’s Modulus and High Toughness Fabricated by Electron Beam Melting

Abstract

A clad structure that consists of solid and powder parts was created from powdered Ti-6Al-4V utilizing electron beam melting (EBM) technique by a single process. The input energy density required to melt the raw powder material was controlled by changing the scan speed of the electron beam from 100 to 2000 mm/s. The finished products showed several types of structures: a dense solid, a periodic layered (clad) structure made up of a solid part and an unmelted powder part, and almost full powder. The products with the clad structure showed a combination of low Young’s modulus and high toughness as characterized by the presence of a stress plateau in the stress-strain curve. Both of these qualities are necessary for feasibility as implant materials used in orthopedic fields. We conclude that the products developed in this study could be useful as bone implants in terms of the mechanical similarity to bones, despite needing only an single EBM process for fabrication.