GB1438554A - Electrodeposition of bright nickel-iron or nickel-cobalt-iron deposits - Google Patents

Abstract

1438554 Electro-plating iron-nickel alloy OXY METAL INDUSTRIES CORP 31 May 1973 [3 July 1972(3)] 03317/76 Divided out of 1438552 Heading C7B NiFe alloy optionally containing Co is electrodeposited from the following bath (a) Fe, Ni and optionally up to 50 wt. per cent of the Ni or Co ions, (b) an Ni brightening agent, (c) an Fe complexing agent containing at least two complexing groups at least one being CooH and the other CooH or OH and (d) a buffer effective to maintain a pH of 2À5- 5À5, e.g. H 3 BO 3 or Na acetate. Optional components are compounds R, NC (R 2 ) SR 3 and XO 3 SRSA, both as described in Specification 1438553. The complexing agent may be citric or gluconic acid (others listed) or a salt thereof including the Fe salt. Conventional Fe, Ni and Co sources (including a soluble Fe or Ni Fe anode) and brighteners are used, examples of the latter being sulpho-oxygen, acetylenic, betaine and N-heterocyclic queteruary compounds. A product containing up to 50 wt. per cent Fe may be obtained at 120-180 F with a c.d of 10-70ASF with or without agitation. A subsequent micro-cracked Cr layer may be plated. The substrate may be steel or ABS, PVC, polyethylene, polypropylene or phenol-aldehyde resins with an initial coating of Cu or Ni. In examples sulphate/chloride baths buffered with H3B03 contain also, (1) NH4 hydrogen citrate, saccharin, allyl sulphonate, butyne diol/ethylene oxide condensate and quinaldine propane sultone, (2) Na gluconate, saccharin, allyl sulphonate, glycerol ether of butyne diol bath sulphonated and unsulphonated, sulphonated epichlorhydrin/ proparyl alcohol adduct and optionally thiourea-S- acetic acid, (3) as (1) but with di-NH 4 citrate and optionally including benzene sulphinate; and (4) as (2) but including both Na gluconate and citrate and with dithiodipropane sulphonate instead of the thiourea compound.