Influence of different friction conditions on the process of cold backward extrusion of steel

Backward extrusion of steel is a deformation process in which very high forces and tool pressures occur. Reduction of such high forces and tool pressures is possible by using an efficient lubricant. This paper describes an experimental investigation of the influence of different lubricants on the stress-strain state within the workpiece volume as well as on the stressing of the die. Best results were obtained when a phosphate-coated specimen was lubricated with MoS₂.