1995 年 59 巻 6 号 p. 640-645
Electro-plating of an alumina particle/nickel composite system was carried out on an aluminum alloy substrate, in which an electrolyte jet was applied to improve the deposition rate and also to realize a required volume fraction of alumina particles. The turbulent jet increases remarkably the limiting current density which is the maximum value required to obtain a qualified deposit. The limiting current density increases as the jet velocity increases, regardless of the alumina concentration in the electrolyte and its average diameter. It is saturated with approximately 120×102 A/m2 at a jet velocity of 4 m/s and becomes 15 times larger than that in conventional plating without a turbulent jet. Alumina particles are then dispersed uniformly in the deposit. The volume fraction of the particle increases up to 30 vol% as the alumina concentration in the electrolyte increases. The volume fraction decreases as the jet velocity increases. It shows a maximum value at a particle diameter of 1.7 μm among the particles 2.8, 1.7 and 0.6 μm in diameter. The resultant deposition rate of alumina particle/nickel composite plating with the electrolyte jet is approximately 15 times faster than that of conventional electro-plating.