Influences of loading paths on thickness of aluminium alloy cup with hydro-mechanical deep drawing

On the basis of hydro-mechanical deep drawing, loading paths to improve the thickness uniformity of cup with a hemispherical bottom were investigated. With numerical simulations and experiments, optimisation of loading paths was carried out. Deformation process and thickness distribution were obtained and the influences of loading paths on thickness distribution were analysed. The results show that there exist two typical points to get thin. With the optimal loading path, the helpful friction force between the punch and the blank improves the stress state of two typical points, serious thinning is reduced, furthermore thickness is more uniform and forming limit is raised.