Effects of different deformation routes of ECAP on AA6063 mechanical properties and microstructure

Abstract

In order to investigate the influence of different deformation routes of equal channel angular pressing (ECAP) on mechanical properties and microstructure of AA6063 alloy at room temperature. The specimens were processed with angle of 120°regarding processing routes A, BA, BC, BC-UD2 and C. Then the macro morphology of specimens was analyzed, the strength and hardness were measured, and the microstructure was observed by SEM. The results show that, after four passes, the deformation of route A is the most inhomogeneity, while route BC-UD2 is the most homogeneity. Route BC deformation is relatively uniform and not easy to generate cracks on up-surface. The increase of tensile strength of route BC and route C is the most. The ductility of route BA and route BC keep best. Route BC can not only improve the strength of the material, but also maintain the plasticity of the material. The hardness improvement and the deformation uniformity show negative correlation under in all routes. The hardness improvement is most obvious after route BA, and the deformation is most homogeneous after route BC-UD2. The microstructure of route C and route BC is equiaxed grain. The average grain size of specimens is smaller after route C.