Archives of Metallurgy and Materials

Abstract

Surface alloying of cupronickel alloy with aluminum uSing tungSten inert gaS proceSSSurface melting and alloying of Copper-nickel (Cupronickel) alloy by preplacing aluminum powder and using tungsten inert gas process (tiG) in shielded atmosphere of argon gas were investigated. Surface melting resulted in the formation of a fairly porous dendritic microstructure. Surface alloying with aluminum resulted in the formation of al 2 Cu and al 4 Cu 9 intermetallic compounds along with Cu-rich matrix and unstable martensitic structure. Surface melting reduced the hardness from 140 hV 0.1 (substrate) to 70 hV 0.1 , mainly due to the loss of cold work effect of the initial substrate. on the other hand, surface alloyed zone showed a hardness of 300 hV 0.1 , mainly due to the formation of intermetallic compound. tafel polarization results indicated improvement in corrosion resistance of cupronickel alloy after surface melting and alloying.