Effect of Asperity Plastic Deformation on the Interface Friction in Metal Forming

Abstract

This paper investigates the effect of the plastic deformation of surface asperities on the interface friction in metal forming involving multi-scale deformation with random surface topography. The equivalent interfacial layer (EIL) introduced by the authors previously was used to integrate the Reynolds equation with the plastic deformation of the randomly distributed surface asperities. The contributions of solid-lubricant interaction, lubricant viscosity and microscopic deformation were therefore included efficiently in a conventional macroscopic finite element analysis. The merit of the method was demonstrated by an investigation into the metal strip rolling, whose friction, lubrication and pressure distribution are otherwise hard to be characterized accurately.