LASER-SURFACE NITRIDING OF TITANIUM AND A TITANIUM-ALLOY

Surfaces of titanium and titanium alloy IMI829 have been nitrided by l aser melting in nitrogen and in a gas mixture containing various propo rtions of argon and nitrogen. The nitrided layers have been characteri sed with respect to their hardness, microstructure, chemical compositi on, corrosion properties and surface finish. Observations are also rep orted on the laser remelting in argon of the as-formed nitrided layers and laser melting of nitride layers preformed by physical vapour depo sition and furnace heating.