Friction behavior in the cup ironing process of aluminum sheets

The object of this paper is to clarity the surface flattening mechanism in the cup ironing process based on the lubricating mechanism. A new experimental apparatus for the ironing process was made and experiments on ironing were carried out with aluminum cups using various lubricants and reductions in thickness. The experiments revealed that on the die surface the friction coefficient becomes minimum under the appropriate conditions of viscosity of lubricant and reduction in thickness. It was also confirmed that the cup surface is best flattened under conditions where the minimum friction coefficient appears.