Effects of Die Surface Roughness on Lubricating Conditions in the Sheet Metal Compression-Friction Test

Abstract

Sheet specimen of soft copper were subjected to plastic compression in plane strain, and then, to measure friction, one of the platens was slid in the direction of sheet width. Combined effects of die surface roughness and oil film thickness on friction are shown as the relations between friction and relative oil film thickness (ratio of mean oil film thickness to die surface roughness). With relatively rough dies, friction decreases with increase in sliding speed, and a corresponding decrease in conformance of the workpiece to the die was observed.