METHOD FOR MAKING AN EXHAUST VALVE FOR A DIESEL ENGINE

摘要

This invention is concerned with an exhaust valve for Diesel engine and a method thereof, in which a seat of the exhaust valve is formed with coated layer comprising ceramics and metals, the layer becoming thicker in density of ceramics as coming nearly to the surface thereof. The seat may be formed with the coated layer by subjecting to pressing-heating treatment after coating. This kind of the exhaust valve is provided by coating ceramics and metals onto a seating portion of the mother material such that ceramics becomes thicker in density as advancing to the surface, and heating the coated layer in electric conductivity while pressing the layer with the tool in non oxidizing atmosphere.