The fragmentation of polycrystalline aluminium (99.8%) at low temperature was studied by X-ray method.
The difference of the deformation progress of aluminium single crystals deformed between at low temperature (-196°C) and at room temperature has been studied with optical microscope, electron-microscope and X-ray.
From defferences among slip bands, deformation bands and cross slip formation, the mechanism of the deformation phenomena at low temperature was discussed.

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The recovery phenomena of electrical resistance and tensile stress of aluminium-magnesium alloys (2, 4 and 6 percent wt. magnesium) annealed at various temperature after deformation at liquid-nitrogen temperature were studied.
The following result was obtaind: (1) The increase in electrical resistance appeared by annealing at a range of temperature between -75°C and +20°C for 4 and 6 percent magnesium, but the decrease in electrical resistance was obserbed for 2 percent magnesium. (2) The tensile stress increases by annealing at a range between -75°C and +60°C for 2 percent magnesium and between -75°C and +30°C for 6 percent magnesium.
These experimental ressults were interpreted by assuming that the interaction between solute magnesium atom and excess lattice vacancy was introduced during deformation at liquid-nitrogen temperature.

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2S slab ingots made by semi-continuous casting process were hot rolled with soluble oil to various reductions, and then the hot rolled stocks were cold rolled without intermediate annealing. The hardness and the microstructure change at the section of the stocks were investigated. The results obtained are as follows: (1) The hardness of the hot rolled stock sections generally tends to be higher from surface to center, and the recrystallized grains appeares in the outer parts of the stocks but not in the innerparts. However, in the outer parts of 72.8% rolled stock (thickness 30mm), the hardness is a little higher and the recrystallization occurs over all the surface, (the grains are smaller than that in the center parts). (2) Heterogenity of the hot rolled stocks affects the properties of the sheets cold rolled without intermediate annealing. In the annealed sheets, grains in the outer parts were in general smaller than that in the center parts in size.

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From the results of hardness measurement on the samples of Al-alloy sheets which contained mainly MgZn₂ about 8% and were quenched by step-wise, the following facts were noticed.
a) Mn and Cr accelerate the softening, making the precipitation of so called “Hardening-Constituents” easier.
b) The effect of quenching stress is similar to that of Mn or Cr.
c) The split-aging effect is conspicuous (in this case, the hardness of the samples tempered after natural aging is greater than that of those tempered immediately after quenching), and it varies according to the quantity of Mg or Zn contained.

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Corrosion tests of copper, iron, zinc, and aluminium in the 5.85 percent sodium chloride containing 0.3per cent hydrogen peroxide were carried out for each metal in the solution by itself, for galvanic couples formed by two of those metals, and for contacts of these three metals, copper-iron-zinc and copper-iron-aluminium.
For uncoupled metals, zinc was corroded most severly and iron was next. Copper and aluminium were less corroded. For galvanic couples, however, basic metal in a couple was corroded preferentially as predicted from the Galvanic Series chart. In the case of contact of three metals, only the most basic metal was corroded, but the other two metals were protected from corrosion. It was observed that the effect of protection by the loss of anodic metal decreased with time corresonding to decrease in corrosion current and then each metal came to be corroded independently after corrosion current reduced to zero. It was concluded that decrease in corrosion current was resulted from thickening of the hydrate film formed on the suface of metal.

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The corrosion tests of the aluminium alloys, 1S, 2S, 3S and 52S which have been used for the anti-corrosion materials, are made in the white dry wine, and their characteristics of anti-corrosion property in the wine are researched.
The aluminium alloys are attacked by the white dry wine, but the reactions are very slow compaired with those in the brandy. 3S and 52S which showed good resistance to the attack of brandy are pronounced largely by the wine, and 1S and 2S which show poor resistance to the attack of brandy are not much affected.
The total acidity in the wine seems almost unchanged notwithstanding the hours of dipping the alloy, but the wine increases its pH-value and grows worse in its flavor and taste and on this occasion the wine becomes muddily white (after about 40 days) and then becomes clear again (after about 90-120 days), but in some cases the colour of wine fades.
We add that this research owes its expence to the Grant-in-aid of the Scholarship of the Institute of Light Metal Foundation.

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Practical process of degassificatien of molton aluminium with Cl₂ gas, was investigated and the resuls obtained may be summarized as follows:
1. The greater the amount of Cl₂ gas is passed through the molten meltal per unit time is, the shorter is the total time for degassification. From these resuts, the following equation was obtained:
t=ke^-M/a
where t: the passing time of Cl₂ gas, M: the amount of Cl₂ gas passed per unit time, a & k: constant.
2. The total amount of Cl₂ gas for degassification was influenced by the amount of Cl₂ gas passed per unit time.
3. The higher the temperature of the molten metal is, the larger becomes the effect of degassification. The activation energy for degassification by Cl₂ gas treatment was about 50, 000cal/mol.
4. The more blisters are on the. sheet surface, the more are the fine fractures This result agrees with our opinion that the blister has much to do with the shrinkage cavity, which are accompanied by very small cracks during solidificaton.

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A series of experimental studies was performed on the kinetics of reaction of commercially pure Ti and Ti alloys with the gas phase H₂, O₂, and N₂, and the report 1 and 2 already dealt with the desorption of H₂ from commercially pure titanium and titanium alloys.
This paper deals with the absorption of H₂ by commercially pure titanium and titanium alloys.
Sieverts' absorption apparatus modified by Prof. Iwase et al was used in this experiment. Specimens were wires of commercially pure Ti, 0.2% C-Ti alloy, 5% Al-Ti alloy, 2% Al-2% Fe-Ti alloy having 0.3m/m diameter, polished by emeric paper.
Solubilities of hydrogen (s) in Ti and Ti alloys subjected to one atmosphere pressure of H₂ were measured at elevated temperature (t) and heat of dissolution of hydrogen in Ti metal was calculaded. When these data are compared to those reported by R. M. Barrer and C. Smithell, we find a definite discrepancy and we assure the latter data should be corrected by this report. Discrepaney is as follows. Although the latter said there was no discontinuity in the curve of log_e S-10⁴T around the temperature of 620°C, we found the clear discontinuity in these temperature. Range and this resuls are consistent with the Ti-H phase diagram offered by R. I. Jaffee et al.

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1. The leakage current, i, of oxide film obtained by anodic oxidation of titanium was treated assuming that the following formula derived statisticlly was valid:
i_=A₀exp(U/kT)sinh(aeF/kT)
where i_: Leakage current
U: Activation energy
k: Boltzmann constant
T: Absolute temperature
e: Electron charge
a: Distance of potential barrier from bottom to top
F: Field intensity of oxide film
A₀: Constant
Or conveniently:
i_=A_sinh B_F
where A₀exp(U/kT)=A_
aeF/kT=B_
The result coincides with the above formula.
A_ and B_ were decided from log i_: logV curve, comparing with y=sinhx curve.
A formula, U=0.17 (e v), was also decided from temperature dependency of leakage current.
2. The leakage current was measured in paste from practictical view point.
It was only below 5μ/cm², and espcialy it was decreased to 1μA/cm², when working voltage was assumed as formation voltage×0.8.

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