Abstract
Nickel-phosphorous alloys 10−100×10−6 m in thickness were produced by pulse plating. X-ray intensities diffracted from the deposits were progressively lowered with decreasing duty cycle of pulse and faded away for the deposit prepared with the duty cycle of 0.2 at the average current density of 2×102 A/m2. The Tafel slope and exchange current for hydrogen evolution of the deposited Ni-P alloys in a sulfuric acid solution were 0.060 V and 10−7 A/m2, respectively, whereas those of Ni were 0.12 V and 1×10−3 A/m2, respectively. Anodic polarization curves of the Ni-P alloys did not exhibit any passivity and were less sensitive to the pH value of the solution. The Ni-P alloy pulse-plated at an optimum condition is highly corrosion resistant in contrast to those produced by d-c plating.
