VALVE SEAT EXCELLENT IN THERMAL CONDUCTIVITY

PROBLEM TO BE SOLVED: To provide a valve seat for internal combustion engine, excellent in a wear resistance and a thermal conductivity.SOLUTION: A facing surface-side layer has a basic part in which hardened particles are dispersed in the basic phase, and the basic part is made to be a ferrous sintered alloy-made having the composition containing 0.2-2.0% C and ≤40% total content of one or more kinds selected from Co, Mo, Si, Cr, Ni, Mn, W, V and S, and a structure dispersed at 5-40 mass% of the hardened particles in the basic phase to the total content of the facing surface-side layer. A sealing surface-side layer is made to be the ferrous sintered alloy-made having the composition composed by mass% of 0.2-2.0% C and the balance Fe with inevitable impurities and the layer is made of 55-90% with the volume % to the total volume of the valve seat. Furthermore, carbon powder is impregnated at 0.5-15 vol% into vacancies in the above ferrous sintered material. By the method, the valve seat having excellent wear resistance and high thermal conductivity can be obtained.