Considerations in Electrodeposition of Compositionally Modulated Alloys

Abstract

High‐quality specimens of sufficient thickness for reliable testing are needed if the enhanced properties observed for ultrastructured multilayered metals are to be understood and exploited. In the present paper, factors affecting the quality of multilayers electrodeposited from a single electrolyte, via concerted modulation of the electrode potential and electrolyte mass transport, are discussed. The importance of precise control of the potential during deposition of the more noble metal is emphasized. Results obtained by a pulse technique show that Ni passivation does not occur under the conditions used to electrodeposit Ni‐Cu multilayers. Attainable deposit quality is illustrated by tensile test data for a series of 90%Ni‐10%Cu specimens that are twice as strong as Ni and for which the standard deviations for the ultimate tensile strength and modulus are only 1.5 and 3.9%, respectively.