PISTON WITH A METAL MATRIX COMPOSITE

A part of a piston (1) is composed of a metal matrix composite (4). The metal matrix composite (4) is composed of a matrix of a light metal alloy and reinforcements formed of metallic fibers mixed in the matrix. The reinforcements are formed of an alloy that consists mainly of Fe and Cr and contains Al and/or Si. The Cr content and the Al and/or Si content of the reinforcements range from 5 to 30% and from 3 to 10%, respectively. The fiber diameter of the reinforcements ranges from phi 20 mu m to phi 100 mu m. The reinforcements are formed by the melt extraction method and have irregular peripheral surfaces. Solution-treatment of the metal matrix composite (4) is carried out within a temperature range from 470 DEG C to 500 DEG C such that formation of intermetallic compounds is restrained.