Nickel-Cobalt Alloy Deposits from a Concentrated Sulphamate Electrolyte

Abstract

The work described in this paper is an extension of an earlier examination of the use of cobalt as a hardening agent for nickel electrodeposited from concentrated sulphamate solutions. Two further areas have been examined: (i) A study has been made of the hardness-retention properties of nickel-cobalt alloys subjected to heating, in order to estimate their potential for heat-resistant coatings and certain electroforming applications where some internal stress can be tolerated, (ii) Operating conditions have been defined for producing moderately hard, low-stress nickel-cobalt alloys without the use of organic stress reducing agents. These conditions may extend the range of applications of the alloys in the electroforming of moulds and dies.