Effects on material formability with high rate forming

Formability may be the most important material property in metal forming.It was reported that the formability of some materials was improved dramatically at high velocities.The main purpose of this paper was to review the studies in the literatures about the factors influencing materials formability of sheet metals under high rate forming conditions.Some main effects were summarized,such as inertial,die impact and changes in constitutive behavior.Inertial was the dominating factor influencing high velocity formability.It acted to diffuse deformation and prevent localization,also responsible for the different necking pattern due to its resulting in multiple necking and preventing localized necking.High velocity impact was also a strong factor and had a stabilizing influence through inertial ironing and reduction in damage parameters due to compressive stresses.High strain rate might induce changes in constitutive behavior,which contributes to improve formability.