Microstructural characterization of interpenetrating light weight metal matrix composites

Interpenetrating metal matrix composites, MMCs, were fabricated successfully by infiltrating of porous ceramic preforms with Al and Mg alloys by a pressure supported casting process. Open porosity of the preforms varied from 50 to 60%, the pore diameters were in the range of 1-10 μm. The microstructure of the materials was characterized using light optical-, scanning electron-, transmission electron microscopy and X-ray diffraction. Several observations indicate the formation of a thin MgAl2O4 spinel at the interface Al2O3 to Mg matrix alloy.