SiC<SUB>w</SUB>/6061アルミニウム合金複合材料の組織と機械的性質に及ぼす複合化プロセスの影響

Abstract

SiC whisker reinforced composites with 6061 aluminum alloy matrix were fabricated by three different processing routes, high pressure infiltration, high pressure infiltration & hot extrusion and powder metallurgy(P/M) & hot extrusion. The structure, age hardening behavior and mechanical properties were compared on the composites obtained. The extruded composites by the P/M process show less uniform distribution of SiC whiskers, but a higher aspect ratio than those by high pressure infiltration. However, the uniformity of whiskers distribution in the P/M composites is improved by using finer alloy powders for the matrix. Tensile strength and elastic modulus of the composites increased with increasing whisker Vf. At room temperature, the highest tensile strength is obtained in the extruded P/M composites from finer matrix powders. Elastic modulus of the cast and extruded composites is higher than those by the P/M route. At 573 K, the cast composites exhibit higher tensile strength than the hot-extruded composites.