Al₂O₃ contained in primary aluminium ingot was already discussed in the previous report. This paper is to report on Al₂O₃ contained in molten metal immediately after tapped out from reduction cell, and also on the effect of fluxing treatment on the impurities contained in aluminium, such as Si, Na, Mg, Zn and B.
In this examination, 99.99% purity aluminium was used as the base metal and Na₃AlF₆, NaF, NaCl, Na₂CO₃, fused salt of Na₃AlF₆ NaCl, -Na₂CO₃, NaBF₄, Na₂SiF₆, ZnCl₂ and MgCl₂ as fluxes.In addition, the effect of Na₂SiO₃ is also discussed in this paper.

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The adding effect of element, that is, Mn, Sn, Fe, Mg and Ti, on the directionality of aluminium sheet, which was discussed in previous report by means of Knoop ratio, is pursued on detecting directionality by means of Harbert pendulum and is traced on effect by X-ray analysis. The results are consistent with ones in the previous report, that is, Mg and Sn are the effective element for controling the directionality, and an evidence that justifies previous report searched the occurrence of ear without the deep drawing test is obtained in this paper. And in this case, it is not easy microscopically to detect the etching pit on surface of sheet and it is unsuccessful in further examination.

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Some usages require soft aluminium which recrystallizes at the possible lowest temperature. It must be very usable and economical if there is aluminium which recrystallizes under the room temperature, especially for producing collapsible tubes, sheathing material for conductor and communication cable.
This study has been made for accomplishing the above mentioned purposes. Small amount of calcium has been added into commercially pure aluminium, which usually recrystallizes at 300°C. Then it has been soaked at high temperature, head-treated for long time at low temperature. The metal thus treated has recrystallized at the temperature lower than room temperature. It has been proved that the impurities contained in aluminium can be almost completely purified by the addition of calcium and heat-treatment. Since, through such treatments, the state of impurities becomes harmless. Besides such a property, this Al-Ca alloy obtains good workability, high conductivity, high corrosion resistance, excellent softness and other properties which are peculiar to super purity aluminium.
It has been also found out that the addition of small amount of tin, nickel and other element together with calcium, facilitaties the purification mentioned above. On this bases, a study has been made on the common properties of element which purfies the matrix of aluminium when they are added to it.

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This is to report on the examination about the effect of ultrasonic vibrations to the solidification of light metals mainly on the micro and macro structure.
(1) 50 cycle per sec. vibrations from electro-magnetic source do not make the grain size of super purity aluminium finer, but, the grain size of some aluminium alloys is made finer by such vibrations, though the dendrites are still remained.
(2) In case of super purity aluminium, 20 kilocycle vibrations from the magnetostrictive generater make its grain size remarkably finer, and in the case of some aluminium and magnesium alloys, such vibrations make their grain size similar to that of permanent mold casting of the same metals, even after slower cooling. The grains thus made finer have not any dendrites.
(3) To prevent from iron melting into the metal, wave guide should be aluminized.

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It is concentrated induction current at the root point of V shaped open edge of stock. Then it is melted and welded by squeeze pressure.
When it is applied high squeeze pressure, welded structure of induction welding is lookwise of hot pressure welding and by low squeeze pressure it is remained cast structure at the welded border.

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In the previous report, the quality standards of the KS-50 commercially pure titanium forgings was clarified and also the correlation between the tensile strength and other mechanical properties and chemical contents.
In this paper, the duality standards of the KS-50 commercially pure titanium sheets which are 1.0mm-1.9mm and 2.0-3.9mm in thickness is clarified. In addition, the analysis of variance for regression of yield strength and elongation upon tensile strength is reported. As the result of the analysis test, it was found out that the regression factors can be distinguished from residual errors at 0.01 probability level.
Regression line, standard error and correlation co-efficient were also calculated. And in addition, the difference of the means and variance of mechanical properties was studied through statistical method on the KS-50 commercially pure titanium forgings and its sheets of 2 different thickness. The difference was then shown by marking evidence in "F" observation values and "t" observation values.
Finally, the metallurgical consideration on the results of the above-mentioned statistical calculation was made.

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