The role of {\beta}-titanium ligaments in the deformation of dual phase titanium alloys

TL;DR

This study investigates how {eta}-titanium ligaments influence deformation and strengthening in dual phase titanium alloys, combining in-situ micromechanical testing with advanced microscopy techniques.

Contribution

It provides new insights into the role of {eta}-titanium ligaments in deformation mechanisms, highlighting their impact on fatigue resistance and strain localization.

Findings

{eta}-titanium ligaments inhibit dislocation motion.

Ligaments influence strain localization during deformation.

Results improve understanding of strengthening in titanium alloys.

Abstract

Multiphase titanium alloys are critical materials in high value engineering components, for instance in aero engines. Microstructural complexity is exploited through interface engineering during mechanical processing to realise significant improvements in fatigue and fracture resistance and strength. In this work, we explore the role of select interfaces using in-situ micromechanical testing with concurrent observations from high angular resolution electron backscatter diffraction (HR-EBSD). Our results are supported with post mortem transmission electron microscopy (TEM). Using micro-pillar compression, we performed in-depth analysis of the role of select {\beta}-titanium (body centred cubic) ligaments which separate neighbouring {\alpha}-titanium (hexagonal close packed) regions and inhibit the dislocation motion and impact strength during mechanical deformation. These results shed light on the strengthening mechanisms and those that can lead to strain localisation during fatigue and failure.