Dislocation etch pits formed by Young’s etchants on (111) surfaces of as-grown Cu and Cu–Al dilute alloy crystals have been observed.
Triangular etch pits of which contrasts were classified into three kinds, dark, light and mixed, were observed in Cu crystals by an optical microscope of low magnification. The forms of these pits were examined in detail with an electron microscope. The dark etch pits were point-bottomed pyramids having sides with inclination angle larger than 0.122 rad, while the light ones took three different forms of shallow pyramids. Mixed etch pits were composed of dark (deep) and light (shallow) parts and moreover they took three different forms. The etch pits of Cu-0.1 at%Al alloy crystals were similar in morphology to those of Cu crystals. However, most of the etch pits of Cu-1.0∼2.5 at%Al alloy crystals were dark or light ones.
On the other hand, with the addition of Al, the etch pits became rounded and their size and slope became smaller. The effect of Al is discussed on the basis of the two-dimensional nucleation theory for the formation of dislocation etch pits.

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A new approach, based on free volume theory, is developed for the calculation of thermodynamic functions of molten binary substitutional solutions. The calculations based on derived equations, which express the thermodynamic properties in terms of experimentally determinable variables at infinite dilution, show excellent agreement with experimental data on a large number of systems and are capable of quantitatively explaining the assymmetric behaviour of these systems. The theoretical variables are interpreted qualitatively in terms of fundamental properties of atoms.

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This paper describes the effect of anisotropy of the material upon the cutting mechanism. The experiment was performed by orthogonal cutting of aluminum plate which is cut off at various inclined angles to the rolling direction, and the cutting phenomenon corresponding to the change of the inclined angle to the rolling direction was examined. Moreover, the obtained experimental values are analyzed on the basis of Hill’s theory.
The results showed that the effects of anisotropy of the material appeared clearly at the cutting phenomenon, that is, the specific cutting force K_s showed such a two cycle fluctuation that K_s gains a maximum value at 30° and 120° respectively and a minimum value at 75° and about 150° when the inclined angle θ changes between θ and 180°.
The relation between the shear angle φ and the inclined angle θ proved to be in fully reverse phase to the K_s-θ curve.
The theoretical values based on Hill’s theory showed qualitative coincidence with the experimental value of shear angle φ, but it was difficult to obtain theoretical conformity with the experimental value of shear stress τ_s.

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The flow rate measurements were made on a mercury stirred inductively by electromagnetic force for simulating the flow rate of molten aluminum. A linear relationship \barn=3.59×10²V_Al+7.22 is found between the average number of grain \barn and the flow rate V_Al in the Al-3 %Cu alloy. The variation in deflection angle of columnar crystals with flow rate were also experimentally determined. A slight convection flow inhibits inverse and gravity segregation, but vigorous stirring results in negative and positive segregation. These phenomena can be explained on the basis of the segregation behaviors during solidification with fluid flow.

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Calculations of the crystal-melt interfacial free energy at the melting temperature have been carried out using a method based upon Ewing’s model in which the interfacial entropy is evaluated from the liquid radial distribution function. A simple expression is proposed for the energetic contribution to the interfacial free energy for the case of average, high-index crystallographic orientations exposed to the melt, permitting the determination of the interfacial free energy for any metal for which a dependable experimental radial distribution function is available. Calculations have been made for 37 metals. The results are found to agree closely with previous experimental determinations of the interfacial free energy from both homogeneous nucleation data (corrected to the melting point) and dihedral angle studies.

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For the complex ionic liquids of type AX–BX₂ such as alkali fluoroberyllates or alkaline-earth silicates, the corresponding-state principle has been established quantitatively between the pairs, (i) LiF–BeF₂ and MgO–SiO₂, (ii) NaF–BeF₂ and CaO–SiO₂ and (iii) KF–BeF₂ and BaO–SiO₂, in their intermediate composition regions under the reduced absolute temperature scale. Experimental data on ionic packing density, viscosity coefficient, and equivalent conductivity have empirically been confirmed to have nearly the same values within experimental errors in the corresponding-state of the respective molten materials. A better understanding of molten silicates and other complex liquids may be obtained from the experiments on molten fluoroberyllates at low temperatures.

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The magnetic and electrical properties of Ni–Mn base polynary alloys have been measured. The specimens investigated are Ni–Mn–Me alloys (Me=V, Nb, Ta, Cr, Mo, W, Fe) containing less than about 24% Mn. The permeabilities depend remarkably on chemical composition and heat treatment. The alloy composition of 79.38% Ni, 8.51% Mn, 5.06% Fe, 3.02% Cr and 4.03% Mo when heated at 1150°C for 3 h and cooled from 650°C to room temperature exhibits a maximum performance. The highest initial permeability of 152.1 mH/m is obtained at the cooling rate of 240°C/h, while the cooling rate of 100°C/h yields the highest maximum permeability of 789.4 mH/m. In the latter the coercive force is 0.104 A/m, the magnetic hysteresis loss 9.2 J/m³/cycle (at a maximum induction of 0.2 T), the saturation induction 0.251 T, and the electrical resistivity 0.847 μΩm at 20°C.

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The process of tempering of the 63.8Ni–1Co–Al martensite has been investigated by electron microscopy. A new ordered phase with the Pt₅Ga₃ type structure is found when the martensite is tempered at relatively low temperatures, 573–673 K, for several ten minutes. This tempered phase is the same in microstructure and configuration of internal defects as the as-quenched martensite except “ordering” in atomic arrangement.

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The factors influencing the crushing strength of a metallised iron pellet has been studied after hydrogen reduction at temperatures between 923 and 1273 K using commercial acid iron ore pellets as the starting material. The results show that the strength is closely related to the degree of maximum swelling rather than to the degree of final swelling. This is considered to be due to the decreasing number of the bonding between the particles of the pellet as the degree of swelling increases. However, when a small number of relatively large cracks are formed in the pellet, the strength is abnormally low despite the small degree of swelling.
The sintering of metallic irons during the later stages of reduction is not sufficient to recover the strength by that of restoring the broken bonding under the present conditions.
The nature of the micropore also depends upon the reduction temperature, and when elongated directional micropores are orientated in a line, they provide a site for crack initiation and the strength of the pellets is reduced.

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