Al or Al alloy poppet valve and a method of manufacturing the same

摘要

An Al alloy poppet valve is used in an internal combustion engine. The poppet valve comprises a valve stem and a valve head at the end of the valve stem. The valve head has a tapered valve face, which is engaged on a valve seat when an inlet port is closed by the poppet valve. The valve face has a thermal hardened layer on the surface end an inner alloy layer, thereby increasing mechanical strength to provide high durability and reliability.