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 ⋅ 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. • The evolution of r -values in Ti-6Al-4V captured experimentally shows distinct trends under static and dynamic strain rates. • VPSC models elucidate the influence of slip system latent hardening on the evolution of r-values under varying strain rates. • Experimentally measured r-values under different loading directions can serve as validation metrics to refine VPSC models.