GB1283417A - High speed electrodeposition of nickel and/or cobalt - Google Patents

Abstract

1283417 Electro-depositing nickel and/or cobalt KEWANEE OIL CO 1 Oct 1969 [24 Oct 1968] 48336/69 Heading C7B A process for the high speed electro-deposition of nickel, cobalt or nickel-cobalt comprises electro-depositing nickel and/or cobalt on a cathode while employing an insoluble anode from a bath that is maintained substantially free from chloride and bromide ions said bath containing a buffered aqueous solution of nickel and/or cobalt ions having a pH of from 2.0 to 3À5 and an unsaturated organic material selected from butynediol, 1, 4-bis (#-hydroxyethoxy) butyne-2, and diethyleneglycolmonopropargyl ether, said buffering being produced by a buffer effective at a pH of from 2À0 to 4.0, during said electro-deposition said bath being passed over said cathode at a rate of at least 300 feet per minute while employing a current density of at least 500 amperes per square foot and operating said bath at a temperature of at least 150‹F. Ni ions may be provided by nickel sulphate, fluoborate, acetate, sulphamate, perchlorate or trichloracetate. Specified buffers (which also exert a ductilizing effect) are the following acids monochloracetic, o-phthalic, dihydroxybenzoic (2, 5), citric, hydrofluoric, succinic, acetic, n-butyric, o-hydroxybenzoic formic, mandelic and melilotic. The buffering agent may have a pKa of from 2.0 to 4À85. Boric acid may be used in addition as a secondary buffer. The insoluble anode may be Pb, C, graphite, Pt, platinized Ti or Pb alloyed with small amounts of Sn, Ag or Co. The anodes may be contoured so as to provide a uniform minimum spacing between the anode and cathode. To provide a uniform flow-rate at the cathode surface baffles may be placed at strategic points. Ni in the bath can be replenished by the use of nickel hydrate, oxide or carbonate or by nickel metal powder or by electrolytic means using nickel anodes in an auxiliary tank.