Squeeze exhaust casting Al2O3 particles dispersed 6061 aluminum alloy composite materials.

The squeeze exhaust casting process for Al2O3 particles dispersed 6061 aluminum alloy composite materials was studied with a special casting mold having vent holes on its bottom, and was compared with the conventional squeeze casting process. The molten metal permeated gradually from top to bottom of the mold and almost all gases escaped from cavity simultaneously, and it had been made possible to obtain the composite containing 0.15μm diameter fine Al2O3 particle with 20-40% in volume fraction. The structure of the composite obtained was fine and homogeneous, and the interstice fraction was less than 1%. The tensile strength of the extruded composite containing 30 volume percent of Al2O3 particles was 63kgf/mm2 and the elongation was 5% at room temperature. At 250°C the tensile strength becam 20kgf/mm2 and the elongation increased to 27%.