Polycrystal plasticity modeling of the anisotropy of Ti-6Al-4V under static & dynamic loadings

Traditionally, sheet metal-forming involves deforming a thin metal sheet at relatively low strain rates. However, to enhance productivity and formability, the adoption of high strain rates in metal-forming processes has gained momentum in recent years. In this study, the visco-plastic self-consistent (VPSC) model was employed to investigate the evolution of the Lankford coefficients ($r$-values) in Ti-6Al-4V sheet metal, measured through tensile testing at 15° increments between the rolling and transverse directions, across three nominal strain rates: $8\cdot {10}^{-5}$, 0.5, and 1000 s${}^{-1}$. The VPSC results demonstrated that optimizing latent hardening coefficients is an effective approach for modeling the evolution of $r$-values across different strain rates. The variations in slip system activities across different loading directions offer valuable insight into the evolution of $r$-values between low and high strain rates.