Effect of deformation routes on microstructure of AA6063 during equal channel angular pressing

Abstract

Equal channel angular pressing (ECAP) is one of the methods to prepare ultrafine-grained materials by sever plastic deformation. The materials with large grain size can be extruded at room temperature. The present work investigates the influence of different deformation routes on microstructure evolution and electrical conductivity at room temperature of ECAP processed AA6063 sample. Samples were processed with four different routes (A, BA, BC and C) in the ECAP die. The microstructure and electrical conductivity of the specimen after ECAP were measured. The results show that with the increase of extrusion passes, ECAP can fragment the large AlFeSi phase to small particles (length (1−3)μm) and homogenize the small particles. After four passes of ECAP, the grain of the sample is refined, and the grain size is about 0.55μm. The order of average grain size from small to large is C < A< BA < BC. The sample has a good grain refinement effects after route C, while it is significantly distributed inhomogeneous for route A. The electronical conductivity of different routes is in the order of A > BC > C.