The authors investigate the flux used for the treatment of molten aluminium for the purpose of determing whether the crast smelting fused salt which is a by-product from titanium Kroll process can be used or not for aluminium flux. And we are determined useful ranges of this fused salts. To these fused salts are added various compounds of chloride and fluoride for comparison. Effective degree of flux is measured by the fluidity length of molten aluminium in horizontal straight line mould after treatment. The results are as follows:
1) In basic binary system containing each elements of MgCl₂, NaCl, and KCl, MgCl₂(60)-KCl(40), MgCl₂(60)-NaCl(40) and NaCl(80)-KCl(20) are effective moreover in binary system containing CaF₂ in place of MgCl₂, CaF₂(60-80)-KCl(20-40), CaF₂(20)-NaCl(80) are effective.
2) In ternary system of MgCl₂, KCl, NaCl, effective compositions are divided into 3 groups as follow. A group is MgCl₂(10-20), KCl(60-80), NaCl(10-20). B group is MgCl₂(10-50), KCl(40-50), NaCl(10-50). C group is MgCl₂(40-80), KCl(10-20), NaCl(10-50). In the above 3 groups, the best effective group is B. C group is most stable, having low melting point and the range of composition is wide.
3) In ternary system of CaF₂, KCl, and NaCl, CaF₂ which is used in place of MgCl₂ is effective, quite contrary to the inefficient MgCl₂. Therefore any compound of MgCl₂ will become effective by adding a certain amount of CaF₂.
4) In A(MgCl₂ 60-KCl 20-NaCl 20)+CaF₂ and A+NaF systems, effective compositions are A(80)+CaF₂(20) and A(90)+NaF(10).
In A+CaF₂+NaF system, a mixture of 60%A, 20% CaF₂ and 20% NaF is effective. More addition of NaBF₄ to the system of A is also effective, the amount of NaBF₄ being 0.5% of the molten mass by weight.
5) The most effective flux for Al is a mixture of A(60%)-CaF₂(20%)-NaF(10%)-Na₃AlF₆(10%) with NaBF₄ added, the amount of the mixture being 5% and that of NaBF₄ 0.5% of the molten mass by weight.

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It is said that the cold-rolled Al-Mg alloy sheets decrease their tensile strength during ageing. In this paper, the result of study on various effects of ageing on Al-2-8%Mg alloy sheets is reported.
The decrease of hardness and tensile strength of Al-2-8%Mg alloy sheets was recognized from the preliminary experiment.
In order to prevent the decrease of hardness and tensile strength, the authors studied two methods of (1) heat treatment, and (2) addition of the third element.
The results obtained were as follows.
(1) The annealing of 100°C ×1hr. stabilized tensile strength of these alloy sheets, and reduced the rate of increase of elongation.
(2) The addition of 1.0%Cr and 1.0%Mn seemed to repress somewhat the decrease of tensile strength and the increase of elongation.

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The recrystallization temperatures of solution treated and normalised alloys were determined by X-ray method. In the case of Al-Ag, solution treated alloy did not recrystallize up to the temperature of the solubility limit, but that of normalised alloy is not so high. In the case of Al-Cu, the effects of solution treatment on the recrystallization temperature are not so marked. The relation between the plane of precipitation of the precipitant and the slip plane is different from each other of the two alloy systems; the resistance being about the same as that due to the resistance of the precipitant to the recrystallization

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An inhomogenious deformed state is produced in the cold worked metal. This inhomogenious state must be larger in the high symmetric crystal than the low symmetric one. For example, in the alpha-zirconium of hexagonal closed packed crystal, the homogenity or internal stress which is produced by the cold work, must be larger than in cubic iron crystal and in copper.
Thus, if cold worked zirconium were annealed at low temperature or aged at room temperature after cold working, comparatively great size change could be expected, which would be worth while considering the accurate size of zirconium parts of atomic reactors.
Twisted zirconium wire specimens of various working degrees were anneald with whole torsion apparatus which was dipped freely hanging in the oil bath. The temperatures of oil bath were 100, 170, and 300°C, After annealing for proper time, the apparatus was picked up and the returning angle was read at the pointer.
The regults are as follows:-
(1) The strain recovery by low temperature annealing occurres in two stages, the first one is rapid and the second one is slow.
(2) The relationship between the logarithmus of annealing time and the strain recovery is linear.
(3) The strain recovery of zirconium is greater than that of copper.
The process of the recovery at low annealing temperature is expressed by kuhlmann, cottrell's formula. We consider that the inhomogenity owes to the interference of boundaries and the relaxation within grains as considered by Zener.
In the heat treatment for the purpose of releasing those internal stress, the proper annealing temperature range is 300-350°C. For this purpose, as high temperature as possible and the first recovery stage are economical.

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High purity aluminium and its alloy foils were annealed at particularly high temperature and formation treated up to 500V and then electrostatic capacity (C) of these foils were compared with the foil annealed at low temperature (350°). From this investigation, the following result were obtained.
1) In the case of 99.99%Al foils, by elevation of annealing temperature to 500° from 450°, C increased considerably, i. e. 98→11.3μF/dm² and then slightly increased at higher temperature than 500°.
2) 99.99%Al-0.02%Mg alloy foil had a similar tendency to the case of 99.99%Al foils 12μF/dm², but at 500° annealing, the value of C was maximum and at the higher temperature annealing it did not increase.
3) As the annealing time, it needed 2hrs at least.
4) If the oxide film by high temperature annealing were removed, or if the foil were heated at high temperature in vacuum furnace, the volue of C lowered to that of the low temperature annealed foil.
5) The fact that the foil annealed at high temperature had higher value of C might account for the structures, the defect and thermal stress of the oxide film by heating.
6) The particularly high temperature annealing of H. P. Al and its Mg alloy foils was clearly effective to increase the C content, especially in the case of H. P. Al based Mg alloy foil.

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This study is concerning with the electropolishing process with the vibrating anode in phosphoric acid bath based on the patents-(Jap. Pat. No. 128891, 190520, T-Nakayama)
In these experiments the static method and the vibration method have been used symmetrically.
(1) As a whole, the electropolished surface produced by the static method has always shown uneven surface, its reflectivity being up to 80%, but the vibration method gave an extremely smooth surface and its reflectivity reached to 90%.
(2) In the vibration method, the concentration of phosphoric acid to obtain electropolished surface is higher than that in the static method, but it has been possible to perform electropolishing up to a higher concentration than that in the static.
(3) Upon increase of the current density, the surface condition has changed in the order as follows:
A (etched surface)-B (insufficient polished surface)-C (electropolished surface)-D (rough surface)-E (burned surface).
The similar results can be obtained with each concentration as well as with both the static and the vibration method.
(4) With the identical concentration of phosphoric acid, the vibration method produced electropolished surface in a higher current density than the static method, and electropolished surface also can be obtained untill reaching to a higher current density than that of the static.
(5) With the same temperature, electropolished surface can be obtained at a higher current density of the vibration method than that of the static, producing electropolished surface untill reaching a higher current density.
(6) While the static method produces electropolished surface in short time in comparison with the vibration method, the vibration method produces electropolished surface until reaching to a longer electrolysis time than the static.

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Corrosion resistance properties of the aluminium alloys, i. e. 1S, 2S, 3S and 52S which are used as anti-corrosion materials, are examined in baking sherry. Specimens (plates) are dipped in sherry for corrosion tests, and changes of the specimens, for example, amounts of the dissolved specimens, time of disappearance of metallic brilliance of the specimens, etc. are pursued. It seems that the aluminium alloys are attacked more violently by sherry than by white dry wine, and the reactions proceed by the speed nearly equal to that of the brandy, and especially the growth of pitting charactirizes these reactions.
On the other hand, changes of the sherry caused by dipping the specimens are examined, and changes of flavor and palate, the relation between the increase of pH-value and the total acidity of the sherry, changes of the turbidity, etc. are reported in this paper.
By the way, this research owes its expence to the Grant-in-aid of the Scholarship of the Institute of Light Metal Foundation.

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Al₄C₃ in Aluminium has not been yet determined accurately, and its effect on the properties of Aluminium has also been unknown.
To study the holding effect and stain effect on the surface of ingot, it is prerequisite to determine accurately the nonmetallic impurities, such as Al₄C₃ and Al₂O₃.
In connection with those problems, the suitable method for determination of trace of Al₄C₃ in Aluminium has been developed, that is sammerized as follows:
1. When sample is dissolved, Al₄C₃ is decomposed to CH₄. After CH₄ is oxidized to CO₂ in a combustion furnace, CO₂ is absorbed in a special cell. Then Al₄C₃ is determined by measuring the electro-conductivity of the solution through oscillator bridge circuit.
2. When sample is dissolved, explosion or other H₂ evolved together will occur to cause serious disturbance, therefore the mercury substitution method is adopted.
3. As it is easy to measure the conductivity without taking out the solution from the cell, the proceeding of decomposition can be observed continuously.
4. According to these procedures, 0.001% Al₄C₃ will be readilg determined. The result of determination of Al₄C₃ in several ingots by this method is reported.

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The determination of oxygen in titanium and zirconium has been investigated using modified macro bromination-carbon reduction method.
The sample is mixed with carbon and treated with bromine at 825°C (titanium), 925°C (zirconium), using argon a carrier gas. The oxygen in the sample is converted carbon monoxide, which is then oxidized to carbon dioxide with hot copper oxide. The carbon dioxide is absorbed into a weighed bulb containing a sodium hydroxide. The bromine and titanium tetrabromide (or zirconium tetrabromide) are removed by the use of three cooling traps of dry ice and water bath, dry ice and alcohol bath and dry ice bath. To remove the last traces of bromine compounds, the gases are passed through sodium hydroxide. Analytical results for various samples of the material by bromination-carbon reduction method and vacuum fusion method show a good agreement.
As macro bromination-carbon reduction method is of simple apparatus and does not require skilled operation, it can satisfactorily be applied to the routine analysis of oxygen in titanium and zirconium.

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