Effect of current density on composition and structure of electrodeposited Au–Ni alloy coatings. (July 2013)

• Record Type: Journal Article
• Authors: Monev, M; Pfund, A; Beck, G; Petrov, K; Bretzler, R; Heuberger, U; Zielonka, A
• Is Part Of: Transactions of the Institute of Metal Finishing. Volume 91:Number 4(2013:Jul.)
• Page Start: 176
• Page End: 181
• Publication Date: 2013-07
• Subjects: Electrodeposition -- Au–Ni alloys -- XRD; Metals -- Finishing -- Periodicals; Metals -- Surfaces -- Periodicals; Metallurgy -- Periodicals; 671.705
• DOI: 10.1179/0020296712Z.00000000088
• Languages: English
• ISSNs: 0020-2967

Abstract

Abstract : The effect of current density on composition and structure of galvanic Au–Ni alloy coatings electrodeposited from weakly acidic additive free electrolyte was investigated. At low current density (up to ∼10 mA cm −2 ), light yellow coloured alloys enriched with Au are deposited. At higher current density the Ni content is abruptly increased and the coatings become coarse and dark. Deposits with an average content of Ni up to ∼50 at-% were obtained. Only a small amount of Ni (up to 20 at-%) takes part in the formation of non-equilibrium super saturated Au–Ni solid solution. The remainder of the Ni is deposited in the interglobular space as an amorphous Ni oxide–hydroxide or as Ni bearing hydroxide salts. Besides Ni, the alloy coatings contain C, N, O, K and H.