Effect of equal channel angular pressing (ECAP) on microstructure and properties of Al–SiCp composites

Aluminium metal matrix composites were processed by stir casting technique with commercially pure aluminium as the matrix material and 5, 10 vol.% of SiC (30 μm) particulates as the reinforcement. Al–SiCp composites were subjected to severe plastic deformation through equal channel angular pressing (ECAP). As cast Al–SiCp composites shows uniform distribution of particles and there is no change in the particle distribution after ECAP. It was found that ECAP refines the grain size of matrix material. In Al–5 vol.% SiCp composite grain size was reduced to 8 μm from 45 μm after two ECAP passes whereas in Al–10 vol.% SiCp composite grain size was refined to 16 μm from 45 μm after first ECAP pass. Hardness and compression test were conducted at room temperature to evaluate the mechanical properties of the composites. Both the composites exhibit improvement in mechanical properties after ECAP.