The author investigated the film thicknesses of two species of water soluble acrylic resin paints, Clear and White, adhered to an aluminum cylinder by dip-coating under stationay conditions. The coatings were made on aluminum wires and round bars under the following conditions. Whithdrawal speed: Clear 0.75, 1.75cm/sec, White 0.52, 1.50cm/sec, Radii of test pieces (cylinders): 6 values of R=0.0625-0.5cm, Ca number: 5.11×10^-3-14.7×10^-3, Go number: 0.2-2.0, The following results were obtained from the above experiments. (1) The theoretical values of film thickness adhered to cylindrical test pieces, reported by D.A. White and J.A. Tallmadge, were in good agreement with these experimental results, (2) The theoretical value of film thickness adhered to cylinders (h′_th)could be determined by multiplying the value of theoretical film thickness adhered to plates (h_th) by a coefficient, C_m
h′_th=C_m⋅h_th where C_m=1/2.4G_o^0.85/1+2.4G_o^0.85+0.5/G_oG_o=R(ρg/2σ)^1/2 (3) The relation between h′_th and h′_ov (the measured value of film thickness adhered to the cylinders) was identical with the relation between h_th and h_ov (the measured value of film thickness adhered to plates). The residual coefficients were approximately equal in both plates and cylinders when the coating were made under the same conditions:
h′_ov=K⋅h′_th=K⋅C_m⋅h_th

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It has been reported that some of electrodeposited alloys are not identical with those represented in thermal equilibrium diagrams; for instance, in the electrodeposition of Ni-Sn alloy system, NiSn metastable phase is formed in a constituent of 40-60 at % of Sn. This study relates to Ni-Sn alloys electrodeposited from the pyrophosphate bath. By the microscopic examination (with T.E.M. and S.E.M.) and measurement of hardness, the following results were obtained on the microstructure and phase of the alloys. These alloys formed a supersaturated solid solution in a range of less than about 10 at % of Sn in Ni, formed a single phase of NiSn metastable phase in a range of about 40-56 at % of Sn, and formed two phases of Ni₃Sn₄ (δ₁) and βSn (ε) in the range of more than about 56 at % of Sn. In the direct observation with T.E.M., the alloys, containing less than about 56 at % of Sn, formed nebulous crystals constituted by microcrystallites of about 50-100Å in size; on the contrary, the alloys containing Sn more than the former, were constituted by many large crystallites of about 300Å in size. The morphological observation of surface with S.E.M. showed that the alloys of less than about 10 at % of Sn had many microcracks, but the alloys of more Sn than that had no microcracks; and the alloys of about 40-56 at % of Sn were very smoothly electroplated. The Ni-Sn alloys forming metastable phases increased in hardness, which was Hv 550-750 at about 50 at % of Sn.

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The inhibition effects and mechanism of benzotriazole (B.T.A.) on tarnishing and corrosion of silver were studied by means of potentiostatic polarization curves, differential capacity-electrode potential curves, and accelerated testings in H₂S and SO₂ atmospheres. It was recognized that B.T.A. had little inhibition effects in acidic solutions (pH 2.5), but had great effects in almost neutral solutions; because, B.T.A.-Ag complex was formed on the surface in anodic potential region, and B.T.A. was adsorbed on the surface with lone electron-pairs of N-atoms in cathodic potential region. Silver treated with B.T.A. had an enhanced resistance to tarnishing in H₂S atmosphere. It was considered that the prevention would be due to the formation of stable B.T.A.-Ag film on the surface. The galvanic corrosion of silver-plated panels occurred in SO₂ atmosphere, leading to the copper base owing to the presence of pores, was much more markedly inhibited by electrolytic treatment than immersion treatment in B.T.A. solution. It was found that the change in the surface coverage (θ) of B.T.A. treated copper conformed to Langmuir's adsorption formula expressed as follows: θ=Km/(1+Km), where K: adsorption constant and m: concentration of B.T.A. Then, the changes of K by immersion treatment and by electrolytic treatment were measured. As the results, a larger value of K was obtained by electrolytic treatment. Therefore, it was considered that the adsorption of B.T.A. on copper through pores became easier by electrolytic treatment.

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