Young's modulus of elasticity and its change with magnetization, that is, the ΔE-effect in the annealed state of ferromagnetic nickel-copper alloys, have been measured in detail at ordinary temperatures by the method of magnetostrictive oscillation, which was described in a preceding paper. The measured range of magnetic field for the ΔE-effect is up to about 900 oerstcds.
The general course of the change of Young's modulus accompanied by an increase of magnetic field or intentisity of magnetization, is similar for alloys of any compositions here investigated. The modulus increases quickly at weak fields, but the rate of increase diminishes gradually with growing field, finally the change of the modulus attaining a saturation. As for the relation between the change of the modulus and the intensity of magnetization, the modulus increases more and more rapidly from the low to the high magnetization range, but once the rate of its increase diminishes slightly, and afterwards the modulus shows a rapid increase in the magnetization range adjacent to its saturation.
The detailed observation of the ΔE-effect reveals, however, the following two particulars. In the first place, Young's modulus in alloys of an intermediate composition range (5_??_21 weight percent copper) decreases, that is, ΔE/E (the change of the modulus, relative to that in the non-magnetized state) becomes negative, though slightly, at first at very weak fields or in the very low magnetization range, and makes a minimum before it increases rapidly with further increasing field or magnetization. Secondly, in nickel and alloys of high nickel compositions (below 15.5 percent copper), the modulus increases somewhat rapidly again in the field range just preceding the saturation.
The saturation value of the relative change of Young's modulus, (ΔE/E)∞, decreases with increasing copper content, but the course of decrease is by no means monotonous, making an inflexion in the composition range of 10_??_15 percent copper. An extrapolation of the (ΔE/E)∞, vs. composition curve shows that the ΔE-effect vani-shes at the composition of about 34 percent copper, and this composition coincides with that at which the ferro-magnetism disapears at ordinary temperatures. The curve calculated on the basis of theories agrees qualitatively well with the measured one. It is also shown that a quantitative difference recognized between (ΔE/E)∞ vs. composition curves of the two sets of alloys of different origins can be explained in terms of the difference in their initial susceptibilities.
The rate of a rapid increase of Young's modulus at weak fields, the intensity of magnetic field at which its increase saturates, its temporary decrease in the very weak field or magnetization range, and the intensity of magnetic field at wihch its secondary somewhat rapid increase occures, all decrease with an increase of copper content.
The relation between Young's modulus at the non-magnetized state and the composition shows a considerably complicated aspect. The modulus increase at first with an addition of copper to nickel, makes a maximum at about 10, a minimum at about 15, and again a maximum at about 20 percent copper, and then it decreases with further increasing copper. The existence of the minimum at about 10 percent copper has never been found.

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Im folgende ist über die Versuchsergebnisse über die Rekristallisationserscheinung warmverformtes Aluminiums und Duralumins berichtet.
Nach den Zugversuchen bei hohen Temperaturen, die Proben wurden geglüht bei verschiedenen Temperaturen. Die merkliche Rekristallisationserscheinungen sind fast immer beobachtet in der Probe welche bei der Temperatur oberhalb der Verformungstemperatur geglüht war. Aber die warmverformten Probe oder die bei der Temperatur unterhalb der Verformungstemperatur geglühten Probe zeigten keine Rekritsllisationsstruktur. Im allgemeinen, die Glühung bei der Verformungstemperatur übt auf die nachherigen Rekristallisationser-scheinungen keinen merklichen Einfluss aus.
Die Beziehungen zwischen die Rekristallisationstemperatur und die Verformungsgraden sind gemessen, wie in Abb. 18 und 19 gezeigt sind.

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An enormous number of duralumin rivets are used in making an aeroplane. As Duralumin is an Aluminium alloy age hardens very quickly after quenching almost of its maximum property, then the riveting work sometimes encounters several inconveniences and is lowerd its efficiencies.
The present work is carried out to reduce these troubles. By an addition of Mn more than one percent on the alloy Al+Cu2+Mg2%, the hardening process in the ageing curve at 25° is suppressed about 120 hours after quenching. Above alloy is named D4. Improveing the D4 alloy, a few alloys were obtained as shown in following table. The riveting material invented in “Heinkel” Company is reffered in the same table.

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Silica brick are used mainly for several industrial furnaces such as steel making or coke oven and 70% is used for the steel industry. As the open-hearth furnace for steel making tends to elevate the operating temperature, the better quality of silica brick is required. Silica bricks of especially good quality must be used for the port and roof of the service furnace, having superior properties as no sudden expansion, spalling and strong at service high temperature.
Steel maker wants the silica brick with such good properties which do not spall or crack at the working temperature and drop down in rice-jelly state - that is, plastic at high temperature. In order to get the above good silica brick, we must use proper raw materials by suitable making process. As silica brick has commonly several transformation of crystal during the burning, the brick with stable structure must be produced.
In this work, the author reports the manufacturing process of silica brick, distribution of particle and burning temperature effects most its quality and the best silica brick used in the open furnace is proved by those having the most viscous or plastic property at the working high temperature.

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It is well known that the recrystallization velocity v of a cold-worked metal is expressed by the following equation:
v=Ce-Ar/RT
where C is a constant and Ar is the activation energy of recrystallization. As the process of recrystallization can be regarded as a sort of so-called “Platzwechselvorgang”, Ar should have the same order of magnitude as the activation energy of self-diffusion As. Plotting Ar of pure Cu against the degree of cold-working, as shown in Fig. 1, the present author has found that Ar tends to the value of As at the zero of cold-working degree. The calculation of Ar was carried out from the data of Karnop and Sachs, who had measured the time required to recrystallize a certain definite degree at various temperatures. The value of As of pure Cu was cited from Rollin.
It is interesting to see how this fact will serve to the development of the theory of recrystallization. The state of things is very disadvantageous to one of the current theories, which postulates the spontaneous melting at the locations where recrystallization takes place, for Ar is about ten times larger than the heat of fusion, which is about 3000 cal/mol in the case of Cu.

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