|About this Abstract
||Materials Science & Technology 2019
||Powder Metallurgy of Light, Reactive and Other Non-ferrous Metals
||Analysis of Grain Boundary α Phase in Hydrogen Sintered Powder Metallurgy Ti-6Al-4V
||Matthew Dunstan, James D Paramore, Brady G Butler, Z. Zak Fang, Jonathan P Ligda
|On-Site Speaker (Planned)
Titanium alloys prepared by powder metallurgy often face many challenges with regards to fatigue properties due to inherent porosity and the coarse lamellar microstructure that forms from the high sintering temperatures. Through the hydrogen sintering phase transformation process (HSPT), Ti-6Al-4V can be produced with high relative densities and an ultra-fine grained microstructure, resulting in fatigue properties that are approximately double that of vacuum sintered Ti-6Al-4V. Additionally, the HSPT process can be used to form a bimodal or globular type microstructure without thermomechanical deformation. Previous fatigue analysis of these microstructures has shown a competition between porosity and microstructural failure, however, the identity of these microstructural features has been unknown. Though contrary to conventional titanium understanding, these failure features are identified as grain boundary α phase. In this work, an in-depth analysis of the various morphologies of grain boundary α and how they contribute to fatigue failure in HSPT Ti-6Al-4V is given.