Decreasing the vortex casting defects of Al-based composites using ECAP and extrusion processes

Stir casting (vortex technique) is one of the simplest methods for producing metal matrix composites. Due to the formation of agglomerated particles and large amounts of porosities, these fabricated composites have very low mechanical properties. The effects of hot extrusion and warm ECAP on the microstructure and mechanical properties of these composites have been investigated in this study. The experimental results indicated the appreciable effects of these secondary processes on the tensile and ultimate strengths, ductility, relative density, hardness, and microstructures of the as-cast composites. In addition, it was revealed that warm ECAP (at 200 °C) and hot extrusion (at 500 °C) have completely different effects on properties of as-cast composites.