Effect of Martensitic Transformation on Elastic Modulus Anisotropy of Ti-6A1-4V Alloy

The Young's modulus (E), Poisson's ratio (v) and anisotropy parameter (A(G)) of alpha ' phase, which obtained from different solution treatment and water quenching temperature, were investigated using first-principles calculations based on density functional theory (DFT). The calculation results showed that the Z-axis value of the elastic modulus of alpha ' phase was higher than that of the X-axis and the Y-axis, indicating the elastic modulus of alpha ' phase was anisotropic. It was decreased with increasing the solution treatment and water quenching temperature for the elastic modulus amsotropy of alpha ' phase. In order to verify the calculation results, the elastic modulus anisotropy of macroscopic Ti-6A1-4V alloys, which were treated at 850 degrees C, 900 degrees C and 950 degrees C, were tested by the tensile and the compressive experiments. The experimental results showed the same change tendency with the calculation results. It concluded that the elastic modulus anisotropy of macroscopic alloy could be controlled by the elastic modulus amsotropy of alpha ' phase.