Patent ID: 6073912
Filing Date: 2000-06-13
Classification: F01L,Y10T

Abstract:
A poppet valve made of an Al or Al alloy matrix in an internal combustion engine, said valve comprising a valve stem and a valve head at an end of the valve stem said valve head having a valve face which is engageable on a valve seat, a reinforcement metal selected from the group consisting of Ti, Cr, Ni, Cu, Mn, Fe, and Co being supplied onto the valve face, and melted to make a reinforcement alloy layer, a surface of which is heated for several hours at about 500.degree. C., rapidly cooled by water quenching, heated at 100 to 200.degree. C. for several hours, and melted again with heating to make a thermal hardened layer on the reinforcement alloy layer of the valve face, said reinforcement alloy layer being higher in hardness than the matrix of the poppet valve, the thermal hardened layer being higher in hardness than the reinforcement alloy layer.