Zinc-alloy electrolyte and process

An aqueous acidic electrolyte for electrodepositing a zinc alloy on a substrate comprising:

• (a) zinc ions present in an amount sufficient to electrodeposit zinc,
• (b) at least one additional metal ion selected from the group consisting of nickel, cobalt and mixtures thereof present in an amount sufficient to electrodeposit an alloy of zinc-nickel, zinc-cobalt and zinc-nickel-cobalt,
• (c) a brightening amount of a primary brightener,
• (d) a carrier brightener present in an amount effective to refine the grain of the zinc alloy electrodeposit,
• (e) an auxiliary brightener present in an amount effective to impart supplemental brightness to the zinc alloy electrodeposit,
• (f) a ductilizer present in an amount effective to impart ductility to the zinc alloy electrodeposit comprising a compound as well as the bath soluble and compatible salts thereof corresponding to the structural formula:
• ##STR2## wherein:
• R is H or C.sub.6 -C.sub.10 aryl, or C.sub.6 -C.sub.20 alkyl aryl in which the alkyl group is C.sub.1 -C.sub.4 ;
• or C.sub.1 -C.sub.22 alkyl, or C.sub.2 -C.sub.10 heterocyclic nitrogen compounds having at least one tertiary or quaternary ring containing nitrogen;
• as well as the mono, di or tri substituted derivatives thereof including --OH, --SO.sub.3 H or --COOH;
• the Group I and II metals and NH.sub.4 salts thereof;
• and the aldehyde, ketone and ether derivatives thereof;
• X is R or --OR' or --NR.sub.2 ' in which R' is H or a C.sub.1 -C.sub.4 aliphatic radical;
• and
• Y is H or SO.sub.3 H;
• as well as the compatible water soluble salts thereof.