The mechanical response of Al-Si-Mg/SiCp composite:: influence of porosity

The effect of porosity on the mechanical and fracture behaviour in Al-Si matrix alloy and composites reinforced with SiC particles of 10 and 20 vol.% in the as-cast state and after extrusion process has been studied. Matrix alloy and composites were fabricated by compocasting and extrusion. Samples were characterized by optical microscopy, image analyzer, scanning electron microscopy and tensile tests. The results demonstrate that hot extrusion considerably reduces the porosity, while size and distribution of the reinforcement particles are also affected. In the point of fracture behaviour, the existence of large porosity is more effective. (C) 2003 Elsevier B.V. All rights reserved.