Osaka Municipal College of Design

Dense and continuous Cu-Zn alloy deposits were obtained from pyrophosphate baths containing histidine. Although neither Cu and Cu-Zn alloy deposits from baths without histidine nor Cu deposits from bath containing histidine showed a smooth surface morphology at 0.5A/dm2 or above, Cu-Zn alloy deposits from baths containing histidine had a smooth surface at even higher current densities. This was because the partial current densities of Cu deposition were extremely low in the alloy baths containing histidine and did not attain the diffusion limited current at above 1.0A/dm2. Smoother alloy deposits were obtained from baths containing Zn2+ ion concentrations of 0.05M or higher. Preferred orientation to the (110) facet was observed in the deposits obtained from baths with Zn2+ ion concentrations of 0.05M or higher at current densities of 1.0A/dm2 or above. Both the smooth surface and the (110) preferred orientation of the deposits from the baths with high Zn2+ ion concentrations are attributed to high overpotentials. Both the Cu and Zn in the alloy deposits from the baths containing histidine were entirely in the metallic state, and formed an α solid solution and/or a β intermediate phase.

An attempt was made to electroplate a uniform and defect-free Ni-Al dispersion coating which is rich in Al particle content. Since bare Al particles without surface treatment quickly dissolved into a Watts Ni bath and yielded cracked deposits, the particles were surface-treated with one of silane coupling with γ-aminopropyltrietoxy silane (γ-APS), boiling in distilled water for 20min., or electroless plating with a Ni-B alloy. Although these treatments strongly suppressed the dissolution of Al into the bath, baths containing the silane-coupled Al particles still yielded a cracked deposit. Deposits that were crack-free and uniform in Al particle distribution were obtained from baths containing the boiled Al particles or the Ni-B plated Al particles, the surfaces of which were composed of Al (OH)3 or Ni (OH)2, respectively. Among many plating variables, diluting the watts Ni bath and decreasing the stroke of the pumping plate were found to be quite effective in increasing the Al particle content of the coating.

Abstract The objective of this study is to construct two models to support decision making for energy systems of a metropolitan area. First, the future energy demand of the region is estimated based on a socio-economic development plan. Next, a planning problem for an energy supply system is formulated as a mathematical programming problem with multiple objective functions under the constraints of energy demand-supply balances and of environmental protections. Both the end-use energy price and the percentage of electricity generated within the region are reflected in the- objective functions. Applying the parametric algorithm in linear programming method, solutions which satisfy Pareto optimality have been derived. The feasibility of these two models has been ascertained through the positive study for Osaka City. Notes † This paper was first presented at the IFAC Symposium on Environmental Systems Planning, Design and Control, Kyoto, August 1977.

There are many methods to take off the pitting on the deposited surface in the high concentration cupper cyanide baths.One of these methods is to add some kind of surface active agent to the bath in order to decrease the surface tension of the bath, and easily separate the bubble of hydrogen gas from the depositing surface.However, for this purpose the surface active agents must have necesarily the following characteristics:1) Not to decompose at high temparature (ca. 75°C), and at high alkalinity (PH 12-13.)2) Not to salt out in electrolyte of high concentration.3) Not to decompose by electrolytic oxidation or reduction.4) To reduce the surface tension of the electrolyte greatly by its addition even in small quantity.From such point of view, we tested and studied nine surface active agents which are presumed to give good effect in alkaline and concentrated salt solution. The high concentration copper cyanide baths containing varying quantities of these surface active agents were made and satisfactory results were obtained in plating in three baths.Conclusions are as follows:1) Ionic surface active agents and polyalcohol ester type nonionic surface active agents can not be used in high concentration copper cyanide bath.2) Polyoxyethylens lauryl alcohol ether, Polyoxyethylene sperm alcohol ether, Polyoxyethylene oleyl alcohol ether of relatively high polymerisation degree(p=20-50) and high purity (98%), decreased pits on the deposited surface without decomposition and salting out.3) By addition of the agents in small quantity, makes it possible to reduce the surface tension of the bath to 50-30dyne/cm (30°C).4) However, it is not possible to remove pitlike hollow caused by adheision of insoluble floating salt (copper complex salt) on the deposited surface and this salt must be removed completely by filtration.