PURPOSE: To obtain the titled parts made of lightweight Al alloy with superior wear resistance by uniformly dispersing graphite in a matrix phase consisting of a prescribed percentage each of Si, Cu, Mg and Fe or Ni and the balance Al and by specifying the grain size of Si.

CONSTITUTION: 5W10% Graphite is uniformly dispersed in a matrix phase consisting of, by weight, 12.5W25% Si, 1W5% Cu, 0.5W5% Mg, 0.5W5% Fe or Ni and the balance essentially Al by a powder mixing method or other method. This Al alloy is melted, and the molten alloy is rapidly cooled to prepare alloy powder. By sintering the powder at a temp. below the eutectic point or hot extruding it, the grain size of proeutectic Si is controlled to ≤20μm. The resulting l alloy has superior wear resistance, strength and machinability, and it is suitable for use as the material of parts for a rocker arm.