A new aqueous plating bath for the electrodeposition of tungsten‐nickel alloys is described. The bath contains sodium tungstate, citric acid, nickel sulfate and ammonium hydroxide. When this type of bath was operated at various bath concentrations and conditions of electrolysis, it was found to yield cathode deposits containing from 10 to 35% tungsten. The maximum tungsten content was obtained from a bath of low nickel concentration; high tungstate concentration; minimum citric acid concentration; a bath pH of about 7; a high bath temperature; and a fairly high cathode current density. The most satisfactory bath contained 20 g . / L NiSO 4 . 6 H 2 O ; 50 g . / L Na 2 WO 4 . 2 H 2 O ; 66 g./L citric acid; and a definite amount of NH 4 OH to give a bath pH of about 8. When this bath was used at a temperature of 70° C and a current density of 7 to 15 amp./dm. 2 , the bright, shiny cathode deposit contained about 35% tungsten and the cathode current efficiency was 40 to 45%. It is suggested that complex ions formed in the bath have much to do with cathode current efficiency as well as appearance and composition of the cathode deposits.

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