Young's moduli of elasticity of annealed iron-cobalt and iron-nickel alloys have been measured by the method of magnetostrictive oscillation at ordinary temperatures. In iron-cobalt system, the modulus vs. composition curve shows two maxima at about 25_??_30 and 60 percent and a conspicuous minimum at about 50 percent cobalt in the α-solid-solution range, and moreover makes a minimum in the composition range where the α and γ solid solutions co-exist. The modulus, then, recovers rapidly in the γ-solid-solution range (80_??_95 percent cobalt), but in the narrow range of ε solid solution it seems to decrease. The curve for iron-nickel system shows a linear and rapid decrease in the α-solid-solution range and in the higher composition range where the α and γ solid solutions co-exist, and it makes α minimum at about 40 percent and a maximum at about 85 percent nickel in the γ-solid-solution range.
Further, according to the results of measurements of the densities at the room temperature of these two binary alloys, the density vs. composition curves show a parabola-like increase in both composition ranges of α solid solution of iron-cobalt system and γ solid solution of iron-nickel system and moreover anomalous changes at their boundaries.

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The newlynamed fatigue deformation is a yielding deformation, and in a test piece occures when it is vibrated under the repeated stress with some mean stress, and when the upper stress overcomes the elastic limit of the material. While it does not occur when the vibrating stress has no mean stress. By the F.S-type ‘Hysterograph’, the torsion fatigue testing machine invented by one of us, the torsional fatigue deformation has been measured on the following four metals: 0·6% C steel annealed and quenched, Ni-Cr steel, brass and duralumin. It has been made clear by these experiments that the fatigue deformation of metals depended chiefly on the static permanent deformation in the vicinity of the elastic limit and the yielding point, but not on the total elongation or the tensile strength of metals. The fatigue deformation concerns with two chracters of constructional materials; one of them is the notch effect of fatigue phenomena, and another the yielding of spring by the vibrating load.

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Aluminium alloys were melted in a mild steel case and were solidified at various degrees of melting temperatures and of cooling speed. And crystallization structures of the ingot thus made have been examined. Aluminium alloys put to the test were made of the same Aluminium blocks given on Vol. 6, No. 2, in adding them Cu 4%, or Cu 4% and Mg 1%. The result was that these alloys, as well as Aluminium blocks, changed from granular to columnar crystals, but unlike the latter a zone of radiant crystals existed. Aluminium alloys containing Cu 4% are more apt to becomd granular crystals than Aluminium blocks, and Aluminium alloys containing Cu 4% and Mg 1% are more apt to become columnar than. Aluminium alloys containing Cu 4% only; …Aluminium alloys containing Cu 4%, on being added Mg also, come to resemble the structure of Aluminium blocks. From results of these experiments, the relation among super-cooling temperature, crystal nucleus and crystallization velocity of crystals has been referred to.

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Pinholes in aluminium alloy castings are due to gas, mainly hydrogen, liberated during solidification of the molten metal, and it remains in the metal as small bubbles. The origin of hydrogen in aluminium was shown by many authors to be ascribed to the decomposition of water vapour by the melt. How hydrogen originating from water vapour is absorbed by the melt, forms the subject of the present report, the results obtained being summarised as follows: - (1) Oxide film on the surface of the molten metal forms a remarkable protective barrier against water vapour. Owing to this protective action of the oxide coating, pinholes seldom occur even when steam is blown against the surface of the melt. The moisture in the atomosphere, therefore, seems to have almost no effect upon the melt, provided that it is coated with oxide film. On the other hand, direct contact with steam by removing the oxide film from the melt results in the formation of numerous pinholes. (2) That pinholes in aluminium alloys castings are mainly due to water vapour from the sand mould has been experimentally proved. Thus, when the oxide coating is removed in casting the metal into the mould, the most favourable condition for the absorption of hydrogen is established. (3) Hydrogen originating from water vapour seems to be in nascent state and has been found to be absorbed with great rapidity, … within 10 seconds.
Prolonged contact of water vapour with the molten metal, however, does not appreciably increase the gas content in the metal. (4) Gases other than water vapour, namely, hydrogen, acetylene, carbon monoxide, and carbon dioxide were blown into the melt to examine their degree of pinhole formation. It has been found that hydrogen at a temperature below 800° is feeble, above this temperature its action gradually becomes vigorous; the action of acetylene resembles that of hydrogen, while carbon monoxide and carbon dioxide are almost inactive in creating pinholes. As the results of the above-mentioned tests, water vapour has been found, to be far more effective than the other gases in creating pinholes. (5) Gas absorbed by the melt can easily be removed by remelting, by treating with dry fluxes, or by maintaining the melt at a suitable temperature for approximately 20 minutes.

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The author has studied quantitative spectrographic analysis with refcrenece to the following fundamental subjects, and has applied its results to practical analysis of various Al-alloys. The presparking time was varied with the respective metals, bbt at least seven minutes were required to get suitable results. The condition of sparking was most stable when special N-Form ø 3.5mm electrode was sparked at the distance of 2.5mm.
The infldence of spark discharging condition, which exerted upon the surface of electrode, was studied in regard to Al-Si (13%) And it was found that, when inductance was large, spark was discharged from the selected portion of electrode. In regard to the influcoce of other elements co-existing on the clement determination, was the effect of Si examined on the Mg determination in Al. Calibration curve of Mg in Al-alloys, when cotained Si also, parted from the straight line, but went back again as inductance increased.
The quantitative results of elements in various Al-alloys have been obtained in the following deviation: Si 5.9%, Ni 4-5% Cr 5.7%, Mn 4.9%, Mg 4.4%, Fe 6.7%, Cu 5.0%, Zn 2.9%, Ti 19.7%.

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Der Übergang zwischen Ordnungs- und Unordnungszustand von Cu₃Pd wurde mit Hilfe der Messungen der dabei auftretenden Änderungen der verschiedenen physikalischen GröBen untersucht. Oberhalb der Kritischen Temperatur, die sich auf die Bildung der long range order bezieht, erkennt mann ein en klcinen Zuwachs des elektrischen Widerstandes. Im Hinblick darauf, daB die spezifische Wärme in jencm Temperaturgebiet noch ihren anomalen Zuwachs beibehält, ist es ersichtlich, dad es sich hier um die Nachbarschaftordnung handelt. Urn nun zu prüfen, ob auf irgendeine physikalische GröBe die beiden Arten des Or nungszustandes verschieden beeinfluBbar sind, wurden die Länge, so wie auch die diamagnetische Suszeptibilität während der Umordnung gemessen. Aus den Messungen folgt, dad eine erhebliche VolumengröBerung mit der Bildung der beiden Arten der Ordnung verbunden ist, wahrend auf der diamagnetischen Suszeptibilität nur die long range order einzigen Einflud hat. Die Zunahme der diamagnetischen Suszeptibilität mit der Bildung der long range order ist, nach dieser Messung, vielfach gröBer als die, die früher von B. Svensson gemessen wurde. Die Ursache der Diskrepanz beider Resultaten liegtl wohl darin, daB die magnetischen Eigenschaften dieser Legierung im höchsten Made von der Vollstandichkeit des Alterungsprozesses bei der kritischen Temperatur abhangig sind.

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Aproposal was submited before by one of us as to the selection of the temperature to obtain the highest value of endrance on the low temperature hardening of piano wires. In the present reseach it was proposed to make sure of that method, and, based on torsion fatigue tests, the relation between duration and temperature of heating was examind. Although it is the general practice to estimate fatigue limits from tension and hardness, it has been found that in case of materials like piano wires, which were cold worked at first by a special mechanical process and thereafter heat treated, the maximum values of tension and hardness did not necessarily accompany the highest limits of fatigue. According to the practice here proposed, indeed, the maximum fatigue limit is about 10% higher than in time of the maximum value of tension and hardness.

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