WEAR RESISTANT RING

摘要

PROBLEM TO BE SOLVED: To provide a wear resistant ring which is stable in ensuring the desired boundary strength when cast in a piston and excellent in bonding property with the piston material (aluminum alloy). SOLUTION: The wear resistant ring formed of a porous metal sintered body is cast in the piston so that the surface roughness satisfies the inequality Rvk×(100-Mr2)}/100>=1.5, and the boundary strength is stably above the desired value. The porous metal sintered body is preferably the iron-based alloy sintered body containing cavities.