|About this Abstract
||2021 TMS Annual Meeting & Exhibition
||Additive Manufacturing Fatigue and Fracture V: Processing-Structure-Property Investigations and Application to Qualification
||The Inhomogeneous Microstructure and Properties of Ti-6Al-4V Additively Manufactured with Electron Beam Freeform Fabrication
||Samuel J. Present, Karen Taminger, Chris Domack, Kevin Hemker
|On-Site Speaker (Planned)
||Samuel J. Present
Electron beam freeform fabrication (EBF3) is a wire-fed directed energy deposition additive manufacturing process that emphasizes a high deposition rate and offers the capability to additively manufacture large-scale structural components in remote space environments. Despite its promise, the relationships between processing parameters, microstructure, and the mechanical properties of material produced by EBF3 are not well understood. This study was undertaken to characterize the inhomogeneous “fish scale” macrostructure of as-deposited Ti-6Al-4V that arises due to the unique thermal history of the EBF3 process. Temperatures in the heat affected zone of subsequent deposition beads exceed the beta transus temperature, which results in a periodic microstructure across the bulk material. The inhomogeneous microstructure gives rise to attendant inhomogeneous mechanical behavior. Location-specific elastic modulus, hardness, and strength were measured with nanoindentation. Fabrication of milli-scale tensile samples and digital image correlation facilitated mapping of strain localization and analysis of the overall response of Ti-6Al-4V builds.