Discontinuous slip at the initial stage of easy glide in copper rich Cu–Al alloy crystals is studied in detail by means of observations of slip lines and etch pits. A new type of discontinuous slip is observed in thin crystals of alloys containing aluminium lower than 3 at% below 200 K . It takes place by a similar process to the propagation of Lüders band. But the boundary between the deformed and the undeformed region is normal to the slip direction and moves discontinuously resulting in abrupt drop in the stress. Dislocations in the deformed region are able to move under a lower stress than the yield stress, so that it is an important evidence that the frictional stress due to solute atoms does not determine the yield stress. This mode of deformation is able to accelerate the operation of the primary slip system without activating the secondary slip systems. The extensive easy glide region observed in low concentration fcc alloy crystals is related to this mode of deformation.

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Electrical resistivity ρ, crystal magnetic anisotropy constant K₁, saturation magnetostriction constant λ_s, and the ΔE effect, ΔE⁄E_o have been measured to investigate the origin of high permeability in the Ni–Fe–Nb system. The investigation shows that the value of ρ for Ni–Fe–Nb alloys increases with decrease in cooling rate and decreases with increase in cold reduction, indicating the formation of the K state in these alloys.
With Nb addition, the absolute values of K₁ and λ_s and the value of ΔE⁄E_o decrease rapidly and become very small near the composition which shows the highest initial permeability, μ_o. These results indicate that the high permeability of Ni–Fe–Nb alloys is probably caused by the very small values of K₁, λ_s and ΔE⁄E_o, that is, by the appearance of magnetoelastically isotropic state.

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The behavior of hydrogen in austenitic stainless steels with different Ni contents, SUS 27, SUS 32 and SUS 42, is studied by means of the ⁵⁷Fe Mössbauer effect. By the electrolytic hydrogenation, Mössbauer spectra of these stainless steels show asymmetric tails, broadenings, and positive isomer shifts. The patterns are analyzed and two main spectral components are obtained. One is from the γ-phase iron not affected by hydrogen, and the other is from the iron atoms which are affected by surrounding interstitial hydrogen atoms. The latter shows a positive isomer shift relative to the former and its absorption intensity increases with increasing Ni content. Computer analyses show the two-component distribution of the isomer shift more precisely and qualitatively and, in addition, exhibits a small third component which may arise from iron-nickel hydride. The observed positive isomer shift might be interpreted in such a way that the 3d holes of iron are partially filled by the 1s electrons from solute hydrogen.
The martensitic transformation of the low Ni austenitic stainless steel, SUS 39, is also studied. Additional broad and ferromagnetic pattern, arising from the α-phase, has an internal field of about 260 kOe at room temperature. The amount of the α-phase increases linearly with the charging time up to 20 hr. This result suggests that the transformation advances into the interior of the specimen at a constant rate.

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The thermoelectric power and the magnetic susceptibility have been measured on the liquid silver alloys of Ag–In, Ag–Sn, Ag–Pb, Ag–Bi and Ag–Sb systems over a wide temperature ranges of about 500 to 1000°C.
The magnetic susceptibility curves at about 1000°C plotted against the alloy compositions are almost linear for liquid Ag–Pb and Ag–Bi alloys, but show a diamagnetic increase in the composition range of 85% to 70% Ag in other silver alloys.
The thermoelectric power varies in a relatively simple way with the alloy compositions for the liquid alloys except for the liquid Ag–Sb alloys which behave in a remarkably anomalous way with a sharp minimum at about 10% Sb and a broad maximum at about 35% Sb.
Calculations based on the assumption of random mixing of constituent atoms in these liquid alloys are performed for the magnetic susceptibility and the thermoelectric power. It is shown that the calculated results are in good agreement with the measurements for the liquid Ag–Pb and Ag–Bi alloys but are different from the experimental results for the other silver alloys. These facts suggest that contributions to these physical properties by the formation of “pseudomolecules” cannot be neglected in the liquid silver alloys except in liquid Ag–Pb and Ag–Bi alloys.

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Anomalous behavior of the thermoelectric power of the liquid silver alloys, Ag–Sn and Ag–Sb, is discussed from the viewpoint of the pseudomolecule model in connection with the experimental results for the heat of mixing, the magnetic susceptibility and the electrical resistivity of these alloys. The heat evolution observed on the mixing of liquid silver with liquid tin or liquid antimony suggests that pseudomolecules having the compositions of Ag₄Sn and Ag₅Sb are formed in these liquid alloys Ag–Sn and Ag–Sb, respectively. The concentration distributions of the pseudomolecules are estimated from the heat of mixing curves of these alloys, and the numbers of localized electrons in these pseudomolecules are also estimated from the magnetic susceptibility of these liquid alloys. From the investigation of the electrical resistivity of these liquids under the pseudomolecule model, the scattering probabilities of electrons by the pseudomolecules are estimated as a function of the energy of conduction electrons for both the liquid alloys. Using these results the thermoelectric power S of the liquid Ag–Sn and Ag–Sb alloys is calculated and the results are in agreement with the observations.

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The influence of delayed failure on the initiation and propagation of fatigue cracks in Ni–Cr–Mo martensitic steel in water was investigated.
The fatigue crack propagation rate in water (da⁄dN)_w is expressed as the sum of the fatigue crack propagation rate in air da⁄dN(=c₁ΔK^m1) and the crack propagation rate in delayed failure da⁄dt(=c₂K_D^m2) as follows: (da⁄dN)_w=da⁄dN+β(da⁄dt)⁄f, where ΔK is the range of stress intensity factor, K_D is the static stress intensity factor, f is the frequency (cpm), β is a coefficient of addition. The perfect or formal addition (β=1) cannot be applied because β is about 0.3 in this experiment, mainly due to the interaction between hydrogen atoms invading into the metal and the cyclic change of the region in the tri-axial tensile stress state.
The number of cycles before the fatigue crack initiation in water N is less than that in air. In some conditions, two bulged parts are observed on the ΔK_a-N curve in water (where ΔK_a is the range of apparent stress intensity factor), and the upper bulge in a short fatigue lifetime suggests the existence of a strong effect of the delayed failure phenomenon on the fatigue crack initiation in water.

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Fatigue tests of thin-foil α-iron were conducted at room temperature and 400°C, and defect structure around a fatigue crack formed in the foil was observed using a 500 kV electron microscope. The main results obtained are: (1) Well-developed substructure was formed around a fatigue crack of α-iron both at room temperature and at 400°C. (2) Extremely small subgrains (\lesssim1μ) and strain-concentrating-region were also found in a thin layer adjacent to fatigue cracks. (3) Several voids or microcracks were always formed in front of the tip of a fatigue crack. (4) The raise of testing temperature resulted in the increased width of strain-concentrating-region, the increased number of voids and the formation of helical dislocation and rows of loops along the ⟨111⟩ direction.
Based on these observations, the growth of fatigue cracks via the formation and linking of voids was suggested. Void formation due to migration and coagulation of vacancies, which had already been proposed for aluminium, was also shown to be possible in α-iron.

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The effect of quenching and tempering structure of various carbon steels on the diffusivity and solubility of hydrogen were studied at room temperature by using an electrochemical permeation technique. The minimum diffusion coefficient is obtained when the steels are in the as-quenched state; i.e, in a martensitic structure the diffusion coefficient increases with increasing tempering temperature. On the other hand, the solubility of hydrogen is a maximum for the quenched martensitic structure and decreases with increasing tempering temperature. An increase in carbon content reduces the diffusivity but increases the solubility of hydrogen. The variations in diffusivity and solubility can be explained in terms of hydrogen trapping process involving lattice imperfections such as dislocations, lattice vacancies and subgrain boundaries, etc, produced by martensitic transformation.

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The growth process of helium bubbles in α-particle bombarded pure aluminum during isothermal anneal at 200 to 645°C for 1 hr to 100 hr was observed by transmission electronmicroscopy and possible mechanisms are discussed. The effects of helium concentration and cold work were investigated.
Helium bubbles are detectable only by annealing above 550°C for 1 hr in both the annealed and cold worked samples. The cold work does not cause any extra coarsening trend of bubbles. The observed types of the bubble distribution are divided into two categories, irrespective of helium concentration and cold work; (1) fine and uniform bubble distribution, in which case the average size is limited to about 200 Å or less in diameter even by the anneal just below the melting point, and (2) the coarsened and nonuniform bubble distribution ranging from 500 to 4000 Å in diameter. The intermediate size bubbles are scarcely found in any cases.
In the above fine bubble distribution, the increase of helium concentration by a factor of two increases the density by the same factor of two, but does not change the mean size of bubbles.
From these two characteristic bubble distrbutions, it is concluded that two different mechanisms are operative in this experiment (1) the growth of bubbles by Brownian motion, in which the growgth rate of bubbles is decreased to almost zero by bubble faceting and this results in the bubble size constancy during the prolonged annealing, and (2) the growth of bubbles by the grain boundary sweep-out mechanism, by which the abrupt coarsening of bubbles is caused. The lack of the intermediate size bubble is explained in this way.

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The internal friction of metal films was investigated by means of the torsion pendulum method. The films were produced by the vacuum deposition on the thin film of sodium chloride over glass substrates. They were removed from the substrates by immersing into water.
It was observed that the free decay oscillation curve of bismuth films has a very high damping coefficient and also has such an asymmetrical form that an exponential decay curve is superposed on an ordinary cyclic decay curve symmetrical about the base axis of time. The initial value of the exponential deviation is found to increase and then saturate with increasing holding time of the films in the initially twisted state. Other metal films which include Ag, Al, Au, Cu, 55 Cu–Ni and Sn films have no such a remarkable asymmetry as observed on bismuth films. It is shown that the behaviour of bismuth films which is observed in the present experiments can be described by the solution for the equation corresponding to a standard linear solid attached by a mass.
The value of Q⁻¹ of bismuth films was determined as a function of temperature for two frequencies. The activation energy estimated from the peak shift and also from the temperature dependence of the holding time necessary to saturate the asymmetry is 6×10³ cal/mol.

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