The effects of Al coating on the life of engine valve as well as various characteristics of Fe-Al alloy layer formed on valve steel by Al coating were investigated. The results obtained were as follows.
(1) The thickness of alloy layer after diffusion heating varied considerably depending on the kind of base steels with the same thickness of sprayed Al layer and other experimental conditions. The thickness of alloy layer on ferritic steel was about twice as large as that of austenitic one.
(2) By X-ray diffraction method, it was found that the Al content in alloy layer of austenitic steel was higher than that of ferritic one.
(3) The oxidation resistance of valve steel was remarkably improved by Al coating regardless of the kind of steels. However, the rate of improvement in the resistance was greater in ferritic steel than in austenitic one.
(4) The corrosion resistance of austenitic Cr-Ni steel to molten PbO was considerably improved by Al coating.
(5) The thermal expansion coefficient of alloy layer was almost equal to that of austenitic steel, but it was much greater than that of ferritic one. The crack formation on alloy layer of ferritic steel subjected to the repeated cycles of rapid heating and cooling was caused by the significant difference of expansion coefficients between the alloy layer and the base steel.
(6) The hardness of alloy layer was very higher than that of base steel up to 600°C, and it was not so much lowered by heating at 700°C for a long time.
(7) It was found by the engine test that Al coating was not so effective for the improvement in the life of inlet valve, but it has considerable effects for the prevention of mechanical and corrosive attacks on exhaust valve, which have been hitherto inevitable.

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The corrosion resistance of hot dipping aluminized steel wire in regard to the effects of additive elements in aluminum bath was studied in comparison with that of galvanized steel wire. According to the above fundamental studies, exposure tests were performed on the aluminized wire with Mn-Al-alloy, the alloy of the highest corrosion resistance, in comparison with galvanized wire in various districts.
The results obtained are summarized as follows:
(1) In the aqueous solution of pH less than 11, the corrosion resistance of aluminized wire was higher than that of galvanized wire; while, in the solution of pH more than 11, the resistance of the former was lower than that of the latter.
(2) In the aqueous solution of 1% HCl, the addition of Mn gave no bad effects on the corrosion resistance of the aluminized wire: though the addition of Si, Ti, Be, etc. gave bad effects. The resistance of aluminized wire with various Al-alloys was remarkably higher than that of galvanized wire.
(3) The results of corrosion resistance in the aqueous solution of 1% NaOH of aluminized wire were much lower than those of galvanized wire, but the addition of Si, Ti, Be, or Mn improved the above results.
(4) The results of corrosion resistance in salt spray test of aluminized wire were higher than those of galvanized wire, and the addition of one of the above elements more improved the results.
(5) The corrosion of galvanized steel wire in A.C.S.R. was advanced by the contact with aluminum wire: while, the corrosion of aluminized steel wire in A.C.S.R. was less than the case of without contact, but rather prevented by aluminizing.
(6) According to the results of salt water immersion test and exposure tests in industrial area, seaside district, and volcanic or hot spring zone, the corrosion resistance of aluminized (with 1.5% of Mn-Al alloy) steel wire was always higher than that of galvanized steel wire.

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The corrosion resistance of aluminized wire is remarkably higher than that of galvanized wire. However, very few reports have so far been made of the corrosion resistance of the aluminized wire produced in Japan. In this report, the corrosion resistance of aluminized wires produced by the authors was studied in various corrosive conditions.
The following results were obtained.
(1) The corrosion resistance of aluminized wire in acidic solution was higher than that of galvanized wire and somewhat higher also in the atmosphere containing acidic gas. However, the former was lower than the latter in most alkaline conditions.
(2) The corrosion resistance of aluminized wire in hot water was remarkably higher than that of galvanized wire.
(3) The corrosion resistance of aluminized wire in sea water was 2 or 3 times as high as that of galvanized wire. Even in the marine atmosphere or in alternate immersion of sea water and atmospheric exposure, aluminized wire was considered to be more suitable for use as compared with galvanized wire.

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Cathode polarization potential during the electrodeposition of Cu from acid sulfate bath was studied by using cubic fibrous structure of Cu (100) substrate and the morphology of Cu electrodeposit was analyzed by the microscopic method as well as electron diffraction method.
By the addition of thiourea to the acid sulfate bath, it was found that the equilibrium potential of Cu electrode was displaced in the positive direction and cathode potential was constant in current density of 0.2-10mA/cm².
It was confirmed that the morphology of crystal growth from acid Cu sulfate bath was varied with current density; i.e., pyramidal in 1mA/cm², cubic layer in 10mA/cm²; and layer and block type in 30mA/cm².
The concentration of thiourea had remarkable effects on the crystal morphology of Cu deposits in the change of size of crystal growth and pyramidal growth extended in [110] direction were varied with the concentration.
By the studies of electron diffraction of Cu deposits it was revealed that the preferred orientation (200) was found in the deposits from lower concentration of thiourea and lower current density. However, no preferred orientation was observed in the deposits from higher concentration of thiourea and higher current density.

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