Structure Property Correlation in Ultrafine Grained Copper Processed by Equal Channel Angular Processing

Abstract

Ultra fine grained copper is produced by equal channel angular processing (ECAP) routes.Multiple passing through the ECAP die reveals high grain refinement in first few passes.Transmission electron microscopies in to the samples reveal a grain refinement of 150 μm to 500 nm sized grains after 4 passes. Mechanical properties measuerement shows that the severe plastic deformation has improved the structural strength to 410 MPa. Structure property study confirms the Hall petch strengthening mechanism operational during the deformation process. The effect of initial microstructral inhomogeniety is investigated and it is found to have marginal influence in the grain refinement of the multiple pass ECAP. Process modeling study using finite element models reveal the developed shear strain and stress fields during the deformtion process.