Plastic deformation of a metal surface in sliding contact with a hard wedge: its relation to friction and wear

Abstract

Experiments are described in which a hardened steel wedge was indented vertically into the horizontal surface of an aluminium alloy specimen with subsequent horizontal movement of the specimen in a direction normal to the edge of the wedge with the vertical force held constant. Forces were recorded during a test and observations made of the plastic deformation of the specimen at the end of a test. Experimental results for a range of wedge angles and different lubricants are compared with results predicted from a slipline field analysis of asperity deformation in which the frictional force is considered to be the force needed to push waves of plastically deformed material ahead of wedge shaped asperities on the harder surface. Although the slipline field results are for an assumed non-hardening material, allowance is made in the calculations for the strain hardening of the actual test material by using average values of flow stress obtained from a stress-strain curve for the material.