CURRENT PULSE WITH REVERSE PLATING OF NICKEL-IRON ALLOYS IN A SULFATEBATH

Ni-Fe alloys were galvanostatically pulse plated on copper rotating di sk electrodes in sulphate solutions. Using a reverse current during th e pulse relaxation period causes the dissolution of both iron and nick el. Anodic passivation of pure nickel was not observed in the binary N i-Fe alloys since nickel dissolves during the period of reverse curren t. Boric acid increases the selectivity of iron in the current-control led process. Higher solution pH enhances both nickel and iron reductio ns. Higher pulse frequency induces a decrease of average nickel deposi tion rate, and as a result, iron composition in the alloy is increased . Raising temperature causes the increase of iron contents in the allo ys.