Abstract: The present invention relates to a process for producing a piston made of hypereutectic Al—Si alloy with a cast iron Alfin ring and a piston obtained through said process. The process according to the invention allows to obtain high adhesion of the Alfin ring to the piston body, making it particularly suitable for use in high performance engines.

Abstract: A piston for a two-stroke internal combustion engine has a crown and a skirt extending from the crown. The skirt defines a reciprocation axis of the piston. A circumferential piston groove is defined in the crown. An annular ring carrier is disposed in the piston groove. A circumferential carrier groove is defined in the ring carrier, the carrier groove being concentric with the piston groove. A retainer is disposed in the carrier groove. The retainer extends at least in a radial direction of the piston into the ring carrier. The carrier groove is adapted to receive a piston ring and the retainer is adapted to prevent rotational motion of the piston ring in the carrier groove, the rotational motion being about the reciprocation axis. Two-stroke internal combustion engines are also disclosed.

Abstract: A spheroidal cast iron, particularly for piston rings for pistons of engines, with a particular alloyed chemical composition and subjected to a heat treatment known as austempering, which comprises an austenitization treatment followed by an isothermal hardening treatment, has mechanical characteristics that are comparable with those of the steel currently used to produce piston rings, while maintening the best tribological and self-lubrification characteristics of spheroidal cast irons, and a process suitable to obtain said spheroidal cast iron.