Microstructure and Mechanical Properties of α′ Martensite Type Ti Alloys Deformed under the α′ Processing

Abstract

Microstructure and mechanical properties of cold groove rolled α′ Ti-V-Al and Ti-V-Sn alloys were investigated. Microstructure after solution treatment at 1223 K and quenching into ice water showed the acicular martensitic structure of α′ phase for (Ti-12 mass%V)-2 mass%Al and (Ti-8 mass%V)-4 mass%Sn alloys and (α′+α″) phases for (Ti-12 mass%V)-6 mass%Sn alloy. After cold groove rolling at reduction of 75%, microstructure evolved into the equiaxed refined cell structure having the preferred rolling texture of ⟨10\\bar10⟩ parallel to rolling direction. After cold groove rolling, Young’s modulus decreases to 47.5 GPa, in contrast, tensile strength increases to more than 1000 MPa accompanying with work hardening and grain refinement.