Metal matrix composite and piston using the same

A metal matrix composite comprising a matrix made of an aluminum alloy and reinforcements mixed in said matrix, wherein:

• said reinforcements are metallic fibers made of an Fe—Cr—Si alloy consisting mainly of Fe and containing 5 to 30% of Cr and 3 to 10% of Si,
• said metal matrix composite is subjected to a solution-treatment at temperatures of 470° C. such that formation of intermetallic compounds on interfaces between said matrix and the reinforcements is restrained,
• said metallic fibers have diameters of φ20 μm to φ100 μm and irregular peripheral surfaces, and are formed by a melt extraction method,
• a volume content of said reinforcements ranges from 10% to 40%, and
• said reinforcements are preformed into a given shape by sintering.

A piston including a metal matrix composite comprising a matrix made of an aluminum alloy and reinforcements mixed in said matrix, wherein:

• said reinforcements are metallic fibers made of an Fe—Cr—Si alloy consisting mainly of Fe and containing 5 to 30% of Cr and 3 to 10% of Si,
• said metal matrix composite is subjected to a solution-treatment at temperatures of 470° C. to 500° C. such that formation of reactants on interfaces between said matrix and the reinforcements is restrained,
• said metallic fibers have diameters of φ20 μm to φ100 μm and irregular peripheral surfaces, and are formed by a melt extraction method,
• a volume content of said reinforcements ranges from 10% to 40%, and
• said reinforcements are preformed into a given shape by sintering.