Heterogeneous Deformation in (α+β) Titanium Alloys—From In Situ Microscopy/Diffractometry to Microstructural Design

The diverse microstructural combinations in (α+β) titanium alloys enable a profuse platform in tailoring the corresponding mechanical performances. The plastic deformation coordination between α and β phases is of fundamental significance in affecting the macroscopic load-bearing responses. However, the underlying deformation micro-events especially their contribution to stress/strain localization and partition still remain elusive and require detailed considerations. This presentation aims to explore the opportunities to combine in-situ digital image correlation and in-situ synchrotron X-ray diffractometry to guide microstructural design of a Ti-Al-V-Fe (α+β) alloy. Specifically, the following fundamental topics will be discussed: (1) what are the deformation micro-events that lead to plastic strain localization? (2) how do stress/ strain localization and/or its partition evolve with respect to the increase of deformation level? (3) how do the identified deformation micro-events affect damage nucleation and thereby macroscopic fracture? Potential microstructural design solutions based on the in-situ study will also be addressed.