Aging effects on the microstructures and mechanical properties of the Ti-20Zr-6.5Al-4V alloy

This study aims to evaluate the effects of heat treatment on the structural evolution and mechanical properties of the Ti-20Zr-6.5Al-4V (wt%) alloy. The alloy was melted via electromagnetic induction, homogenized, transus-processed, solid-solubilized, and then aged at different temperatures (from 450 degrees C to 700 degrees C) for 120 min. X-ray diffraction was used to characterize the phase compositions in the alloy under different conditions. During the solution treatment process, the alloy underwent the following phase transformation: beta ->alpha+beta (retained)+alpha ''+fcc phase. Martensite alpha '' and beta phases transformed into the alpha phase after the aging treatment. The fcc phase became completely dissolved when the aging temperature increased to 700 degrees C. At this temperature, the mechanical properties of the alloy reached their optimum combination at sigma(b)=1437 MPa, sigma(0.2)=1294 MPa, and epsilon=6.69%. (C) 2012 Elsevier B.V. All rights reserved.