Single crystals of nickel, of a slender cylindrical rod form, were prepared by the method of slow solidification, and Young's moduli of elasticity of annealed crystal specimens having various orientations were measured by the method of magnetostrictive oscillation at room temperature. The relation between the reciprocal of the modulus, 1/E, and orientations(γ₁, γ₂, γ₃) was found to be 1/E=0.8349-2×0.6739 (γ₁²γ₂²+γ₂²γ₃²+γ₃²γ₁²)×10^-12cm²/dyne, where γ₁, γ₂ and γ₃ are direction cosines of the rod axis of a crystal specimen referred to the tetragonal axes; Young's moduli in directions of the three principal crystallographic axes, [100], [110], and [111], are E_[100]=1.198× 10¹², E_[110]=2.008×10¹², and E_[111]=2.592×10¹² dynes/cm², respectively. Then, principal elastic parameters, S_ik, were determined by the use of the reliable measured data for the volume compressibility of polycrystalline nickel, which was 0.535×10^-12cm²/dyne; results obtained are S₁₁=0.835×10^-12, S₁₂=-0.328×10^-12, and S₄₄=0.978×10^-12cm²/dyne. The rigidity moduli in directions of the three principal crystallographic axes, computed from the above-determind principal elastic parameters, are G_[100]=1.022×10¹², G_[110]=0.605×10¹², and G_[111]=0.533×10¹² dynes/cm². Hence, the elastic anisotropies are E_[111]/E_[100]=2.16 and G_[100]/G_[111]=1.92, being nearly the same as those of iron crystals. Further, three principal elastic constants, C_ik, were computed to be C₁₁=2.44×10¹², C₁₂=1.58×10¹², and C₄₄=1.02×10¹² dynes/cm²; so-called Cauchy's relation C₁₂=C₄₄ does not hold.
The elastic moduli of quasi-isotropic polycrystalline nickel were calculated from the elastic constants of single crystals by theories of Voigt, Reuss, Huber and Schmid, and Bruggeman, and the calculated values were compared with the measured ones. It was found that theories of Voigt and, particularly, of Bruggeman gave the most accurate values, which were 2.07×10¹² and 1.92×10¹² dynes/cm², respectively, for Young's modulus and 0.78×10¹² and 0.72×10¹² dynes/cm², respectively, for the rigidity modulus. Further, Debye's characteristic temperature was calculated by the use of the computed values for Poisson's ratio, 0.315 and 0.329, which were obtained by the theories of Voigt and Bruggeman, and the results were 451 and 432 °K, respectively.

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From the thermodynamical conciderations, it is expected that the reduction of vanadium oxide will be conducted like that of manganese oxide and accelerated by the co-existence with iron or nickel oxide. C, H. Fougner and E. J. Kohlmer, however, investigated the velocity of reduction of vanadium oxide by hydrogen at 1530° and obtained the results inferior to those above expected. The author, therefore, have studied again, using the absolutely dry hydrogen, the reduction of vanadium oxides at 1000° and 1100°, and have found it to agree with that of the thermodynamical calculations.

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The change in electric resistance of alloys of the iron-nickel system at various temperatures, ranging from -190° to 850°, is measured up to 1600 oersteds in the longitudinal magnetic field. The specimen used is a fine wire, 0.22_??_0.61mm in diameter and cm in length. The change in resistance of alloys, being face-centered cubic solid solution, on the nickel side, is far remarkable than alloys being body-centered cubic solid solution, on the iron side, -especially at lower temperature. The isotheimal curves of concentration of magneto-resistance consist of two portions, separating each other at concentration of nickel slightly more than 30%, and each curve forms a hollow to the concentration axis. Two solid diagrams are constructed from magneto-resistance in 1500 oersteds, and from electric resistance at various temperatures in iron-nickel alloys.

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The characteristics of Fe-Ni alloy, its A₃-transformation and phase boundary between γ and α in the state of equilibrium, have been studied. It is naturally expected that, on cooling or heating with a marked hystersis, the lattice alone can be transformed without any change of concentration. And such lattice transformation was found by these researches to occur only at the time when they were superheated or supercooled beyond the co-existing range of two phases. From the temperature of lattice transformation, the equilibrium diagram of that alloy were drawn in a solid state.

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The effects of mechanical deformation and heat-treatment upon the corrodibility of pure aluminium and some aluminium alloys were examined in connection with the residual internal strain. Utilizing the test piece of specimens prepared under the different conditoins tabulated in Table 1, the measurement of their corrodibity was made on the one hand, to detect the change of the corrosion given rise to by the aforesaid procedures. While on the other hand, the general view, the macro- and micro-structures and the crystalline configuration of these specimens were also studied together with their lattice constant, to estimate the variation of the residual strain from the structural changes.
As a consequence of the investigation thus advanced, it became clear that the chill-cast specimens of pure aluminium and Cu-Al alloys, which have been deformed by the external tension over their elastic limits, were apt appreciably to be more corrosive throughout the whole test piece than these unstrained. But, such a raising of the corrodibility appears unevenly in its amount, according to the part of the test piece; the nearer the part was situated to the areal contracted portion, the more the corrosion became notable, as represented in Fig. 2. With regard to the structural change, the macro- and micro-structures as well as the crystalline configurations revealed with X-rays by the Laue method, were also found to indicate the presence of the more severe residual effects of the external tension in the part nearer to the areal contracted portion, which had been rendered to be more corrosive, as may be seen in Photos. 2, 3, 5 and Photos. 8_??_12 respectively: i.e., the elongation of some of the crystal-grains or dentrites coming to appear in Photo. 2 or 5, and also the distruction of the micro-crystals or the formation of some fibrous-like structures deduced from Photos. 8_??_12 as in the previous researchlb, can be observed alike more clearly at the part nearer to the areal contracted portion of the test piece than those further to that portion. Moreover, the aforesaid parallelism between the change of the internal structure and that of the corrosion of these chill-cast specimens is also detectable by the displacement of lines in the “back-reflected” X-ray spectra reproduced in Photo 14, which shows the more perceptible expansion of the crystal lattice at the part where the corrodibility of the test piece increases the more remarkably. Thus, the corrosion of the chill-cast specimens of pure aluminium and Cu-Al alloys may be deemed to vary, in accordance with residual internal strain disclosed by the structural change due to the external tension.
In addition to those which have hitherto been stated, it is noticed as a patent point of the consequence of the present experiment, that the aforesaid expansion of the crystal lattice was observed to take place not only parallel but perpendicular to the direction of the external tension, similarly as had been pointed out by Wood and Smith⁽²⁾. By making use of the reflection from pure aluminium powder annealed as the reference line, the amount of the lateral expansion of the crystal lattice at the areal contracted portion, was estimate, from the displacement of (333) line, to correspond to the elongation percentage of the order 10^-4 in pure aluminium, but sometimes to exceed the order 10^-3 in 4% Cu-Al alloy.
Here, it must be again postscribed that the facts, thus confirmed with various chill-cast specimens, could hardly be found with the specimens undergone some adding treatments besides the chill-casting, as those of the cold-rolled Cu-Al alloys and ESD alloys prepared by tempering at low temperature. This is probably due to the predominance of the residual strain already kept rather in these specimens, than those given rise to by the external tension.

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Der Einfluβ der Zusätze von Cu, Cr, Mn und Ti auf das Korrosionsverhalten von Al-Zn-Mg-Legierungen wurde durch die gewöhnlichen, beschleunigten Korrosionsversuche, messungen am Festigkeitsverhalten, Eudiometer proben, mikroskopische Prüfungen, und Messungen der Lösungspotentiale und der elektrischen Leitfähigkeiten untersucht.
Nach den Potentialmessungen der Bestandteile von Al-Zn-Mg-Legierungen ergibt sich, daβ die an den Korrigrenzen ausgeschiedenen interrnetallischen Verbindtingen höhere Elektrodenpotentiale besitzen als die zusammenbestehenden mischkristalle, das Potential der ternären Verbindungen unter anderent viel unedler ist. Diese Verbindungen bewirken als Anoden und rufen Spannungskorrosionsrisse stets entlang dem Korngrenzen hervor Dann ist es zu ersehen, daβ die Korrosionsempfindlichkeit der Al-Zn-Mg-Legierungen vorwiegend auf der an den Norngrenzen ausgescheidenen ternären Verbindung beruhe.
Beim Chromzusatz ordenen sich die Ausscheidungen der Al-Zn-Mg Legierungen zeilenförmig an, wäbrend beim Manganzusatz die Kornverfeinerung beigeführt wird. Derartige homogene Ausscheidungen führen nur zu einer gleichmäβigen Abtragung des Werkstoffes und nicht zu einer örtlich beschränkten, gefährlicheren Anfressung. Dies deutet schon auf eine Verminderung der Empfindlichkeit gegen Interkristall-und Spannungskorrosion hin.
Al-Zn-Mg-Legierungen mit Kupfergehalt, die von 450° abgeschreckt und 100° angelassen worden sind, zeigen eine erhebliche Emplindlichkeit gegen intcrkristalline Korrosion. Jedoch durch Zusatze von Chrom und Mangan werden die kupferhaltigen Al-Zn-Mg-Legierungen ihre Neigung zu interkristalliner Korrosion erheblich vermin dert bekommen, und an ihrem höchsten Festigkeitswert zeigen sie die hervorrangende Korrosionsbeständigkeit.

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The conditions for the determination of tungsten in iron and steel have been studied by the use of perchloric acid. Tungsten can be precipitated quantitatively with a single fuming of perchloric acid by the following treatment: the sample is dissolved in aqua regia and evaporated to white fume after addition of 50 c. c. of perchloric acid; after cooling, dilute hydrochloric acid is added and its total volume is made up to 150c. c. so as to adjust the concentration of hydrochlioric acid between 1_??_1.5 N. The solution issued is Warmed at 70_??_80° for an hour and then filtered. Applying this method also to the rapid determination, we have found that tungsten would be determined in about 20 minutes.

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