The origins of microtexture in duplex Ti alloys

Abstract

A previously developed methodology was used to transform electron backscatter diffraction (EBSD) data for the primary and secondary alpha phases of Ti–6Al–2Sn–4Zr–6Mo (Ti-6246) to the prior beta phase. The results established that the observed microtexture in duplex alloys is a direct result of the prior beta grain orientations, and variant selection. In addition, for a homogeneous duplex microstructure, all of the secondary alpha phase and the majority of the primary alpha grains retain crystallographic coherency, according to the Burgers relationship, with the surrounding beta phase matrix, which comprise prior beta grains. This investigation establishes that this technique to recover the prior beta grain orientations is applicable to duplex α/β titanium microstructures. The crystallographic coherency of the primary and secondary alpha phase with the prior beta grain coupled with variant selection then leads to the localized microtexture observed in a wide variety of Ti alloys.