Patent ID: 11913131
Assignee: MACDERMID, INCORPORATED
Field: Surface technology, coating (Chemistry)
Classification: CPC C  B  H | IPC B  C  H

Claim 7:
8. An aqueous alkaline zinc-nickel-iron electroplating bath for depositing a ternary zinc-nickel-iron alloy on a substrate, comprising:
about 4 grams per liter to about 50 grams per liter of zinc;
about 0.1 grams per liter to about 10 grams per liter of nickel;
about 50 grams per liter to about 220 grams per liter of an alkaline compound selected from the group consisting of sodium hydroxide and potassium hydroxide; and
about 2 grams per liter to about 200 grams per liter of a nickel complexing agent; and
a complex consisting of an iron salt and an iron complexing agent, wherein the iron complexing agent is selected from the group consisting of sodium gluconate, sodium tartrate, sodium hydroxybutyrate, potassium gluconate, potassium tartrate, and/or potassium hydroxybutyrate, wherein the complex is formed prior to addition to the electroplating bath,
wherein a concentration of iron ions in the electroplating bath provided by the complex is from about 0.1 gram per liter to about 10 grams per liter,
wherein the electroplating bath is configured to deposit a ternary zinc-nickel-iron alloy containing 7 to 16 wt. % nickel, 0.5 to 8.0 wt. % iron, and the balance zinc,
wherein the electroplating bath is maintained at a pH of more than about 13, and
wherein the electroplating bath is at least essentially free of iron hydroxide.