Production process of a piston

摘要

To improve the abrasion resistance by increasing the ratio of copper content in the copper-type alloy layer on the periphery of the ring groove of a piston. A peripheral groove having a section of a roughly large trapezoidal shape larger than that of the ring groove is formed preliminarily on the outer peripheral face of the piston. While the powder of a copper-type alloy material is supplied to this peripheral groove, the laser beam is irradiated to melt the powder, and a thickening layers is thus formed. The thickening layer of a copper-type alloy is subjected to the machining process to form a ring groove for attaching the top ring,