The conditions of electrophoretic deposition of aluminum powder were investigated by studying the effects of shape and size of powder and concentrations of electrolytes, tannic acid, and water in the suspension. Aluminum powder was deposited on cathode at field strength of 25-130V/30mm from the suspension in ethanol bath with the addition of tri-, bi-, and uni-valent electrolytes such as AlCl₃, MgCl₂, and HCl, which were easily soluble in alcohol.
The best deposition was seen when the concentration of electrolyte was 1m mol/l. When the concentration was lower, the deposition was localized, and when it was higher, the deposition velocity was decreased and the surface of deposits was uneven.
In pure methanol bath, the deposition velocity was higher as compared with in ethanol, but the surface of deposits was very rough.
In the mixed bath of methanol and ethanol at the ratio of 2:3, the deposition was more rapid and more smooth surface was obtained.

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Field tests, exposure tests, and laboratory tests of the coating composed of zinc and other metals were carried out for the purpose of preventing corrosion of track materials in tunnels and the following results were obtained.
1) Corrosive condition in tunnels under steam traction was in weak acid state, but zinc coating was effective for the prevention of cracks in the areas of rail joints.
2) By any procedures of application, the durability of zinc coating was almost proportional to the amount of the coated zinc in the above condition.
3) Corrosion resistance of zinc was sensitive to corrosive condition and the durability of zinc coating highly depended upon the types of tunnels or the positions in the tunnel.
4) Tests were also carried out on other metallic coatings than zinc, but none of them were more effective than zinc coating.

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The degree of uniformity of plating and throwing power by barrel plating was varied with the composition on bath and operating conditions. The effects of the above variables on the uniformity and throwing power were experimentally investigated under various conditions and the following results were obtained.
(i) The throwing power of nickel bath containing brightners was inferior to that of no brightners.
(ii) Throwing power, uniformity of plating, and conductivity were increased with the increase of the diameters of holes on the side plate of the barrel, while the rotation velocity of the barrel should be as high as possible, but it was not permitted to be too high.
(iii) In general, throwing power and the degree of uniformity were decreased with the increase of current density and loading amount.
(iv) When the addition of nickel chloride was replaced by sodium chloride in Watt's bath, conductivity and throwing power were improved. In this case, the throwing power with the addition of brighteners was higher than that of the original Watt's bath.

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