Microstructural Characterization of the Effect of Minor and Severe Plastic Deformation on Martensite Decomposition in Ti-6Al-4V Alloy

Abstract

Martensite decomposition in titanium alloys is the phase transformation most commonly associated with their standard heat treatment – hardening and tempering. However, it also occurs during other manufacturing processes, such as thermomechanical processing and additive manufacturing. Understanding the nature of the martensite decomposition process enhances the ability to control it. Unlike previous studies in this field, which were based on light microscopy (LM) and scanning electron microscopy (SEM) analysis, this study examined the effect of plastic deformation of martensite on its decomposition using transmission electron microscopy (TEM) and EBSD/TKD methods. In addition, a variant of hydrostatic extrusion of the quenched Ti-6Al-4V alloy was also considered.