EBSD Investigation of Ti6Al4V Alloy Processed by Constrained Groove Pressing and Heat Treatment

Abstract

Ti6Al4V sheet metal has found significant applications in the aerospace, defence and biomedical sectors due to its high strength-to-weight ratio and excellent corrosion resistance. The texture plays an important role in tailoring the mechanical properties which can be modified via thermo-mechanical processing. Constrained groove pressing (CGP) is a well-known sheet metal severe plastic deformation (SPD) technique for grain refinement and enhancement of mechanical properties. In this work, high temperature CGP has been performed successfully on Ti6Al4V alloy at 550°C followed by heat treatment at 500°C. CGP and heat treatment led to grain refinement and formation of submicron size grains. The inverse pole figure (IPF) reveals the decrease in texture intensity of basal planes from 5.9 to 4.5 in CGPed Ti6Al4V. Heat treatment further reduced the IPF texture intensity to 3.5. Enhancement in mechanical properties such as YS, UTS and microhardness is also observed. Although slight enhancement is observed in yield strength, ultimate tensile strength has been improved by 21% after CGP and heat treatment. Up to 20% improvements in microhardness have also been observed in processed samples. CGP and heat treatment together can serve as an efficient technique for tailoring microtexture and mechanical properties of Ti6Al4V and other HCP alloys.