Effect of solution and aging on the texture evolution of an extruded metastable β titanium alloy Ti-4Al-6V-5Mo-3Cr-1Zr

Abstract

Compared to α + β titanium alloys, β titanium alloys exhibit superior heat treatment strengthening effects. Specifically, after solid solution treatment followed by two-stage aging, the alloy features finer secondary α (α_s) phases compared to primary α (α_p) phases, resulting in enhanced second phase strengthening effects. This study focuses on the effects of various aging parameters on the texture evolution of an as extruded high strength metastable β titanium alloy Ti-4Al-6V-5Mo-3Cr-1Zr using synchrotron high-energy X-ray diffraction and electron microscopy. After extrusion, two primary fiber textures are formed within the β phase: < 200 > and < 110 > fiber texture. The intensity of β phase texture fluctuates during aging primarily attributed to phase transformations altering the volume fractions of the two phases. The α phase predominantly exhibited the conventional < 0002 > fiber texture, along with an unconventional < 10 \(\overline{1 }\) 1 > component rarely reported in prior studies of metastable β titanium alloys, with their orientations rotating during high-temperature aging. This rotation originates from variant selection during the precipitation of α_s phase from the β matrix, leading to crystallographic orientations distinct from the preferred orientation of α_p phase formed during extrusion.