Breakaway, a sharp increase of corrosion rate of zirconium alloys, was evidenced to be caused by mechanical detachment of protective oxide films, through observation of a remarkable contrast change in SEM secondary electron images of alloy surfaces oxidized in 633 K water. The contrast change was explained by the loss of electrical discharge circuit caused by detachment of oxide films.
The above explanation was supported by examination of Zircaloy samples corroded in 673 K steam, which showed blistering of oxide films and no breakaway in kinetics. Reported changes of oxide microstructure before breakaway also support the film detachment hypothesis.

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Fundamental experiments on the internal oxidation process of vanadium alloys were performed for the purpose of improving the high temperature strength of vanadium alloys. The following results were obtained:
(1) Zirconium and silicon were alloyed to vanadium, respectively, as internally oxidizing elements. Zirconium was found to be more favorable than silicon because of the superior high-temperature strength of the internally oxidized V–Zr alloy.
(2) An excess of oxygen, supplied by decomposition of NiO, increased the amount of oxygen dissolved in solid-solution in the internally oxidized alloy, which caused strengthening of the alloys not at high temperature but at low temperature, accompanied by embrittlement.

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In order to investigate the solid solubility of B in Ni as a function of grain size, the high temperature internal friction of pure Ni and Ni–B alloys containing 0.0035, 0.0068 and 0.010 wt% B has been measured with particular attention to the grain boundary damping peaks. The electrical resistivity was also measured to determine the solubility. The results obtained are summarized as follows:
(1) The solubility of B in single crystal Ni is given by C(at%)=0.59exp(−H⁄RT), H=65.6 kJ/mol.
(2) The apparent solubility of B in polycrystalline Ni increases remarkably with decreasing grain size.
(3) On the Q⁻¹−1⁄T curves of pure Ni, there are two peaks of grain boundary damping at about 470°C and about 670°C. By addition of 0.0035 wt% B, only one peak can be observed. The peak temperature of every Ni–B alloy used is about 550°C and its activation energy is about 330 kJ/mol.

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Four types of aluminum bicrystals having a longitudinal twist boundary parallel to the {111} plane and with a misfit angle of about 0.38 rad (22°) were grown by a modified Bridgman method. The fatigue tests were done on a bending fatigue testing machine and carried out at a constant strain amplitude of about 0.2% and cyclic frequencies of 30.4 Hz.
It has been found that fatigue cracks are initiated along the crystal boundaries. The initiation of the fatigue cracks along the crystal boundaries is due to the operation of the secondary slip systems whose slip planes are parallel to the crystal boundary one.

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Iron was vacuum deposited onto (111)_fcc substrates of nickel, copper and silver. The orientation relationships between the deposit and the substrates have been examined by transmission electron microscopy and selected area diffraction. The iron/substrate interfaces take the orientation relationships of {110}_Fe//{111}_fcc. In the iron-silver system, the orientation relationship is [001]_Fe//[110]_Ag, that is the Nishiyama-Wassermann relationship. In the case of iron-copper system, the iron deposits rotate about an axis normal to the substrate and lead to the orientation relationship in the range from Nishiyama-Wassermann’s to Kurjumov-Sachs’s. For the iron on nickel, the K-S relationship is more pronounced compared to the case of iron on copper system. These results can be understood by the concept of good atomic fitting area at the interface.

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In order to clarify the relative importance of various factors for solute diffusion of impurity cation, the inter-diffusion coefficients of the silver ion in molten alkali chlorides were determined by use of the capillary reservoir method at the temperatures ranging from the melting points of solvent salts to 200 K.
The results obtained can be summarized as follows:
(1) The temperature dependence of the inter-diffusion coefficient of the Ag⁺ ion was well represented by an equation of the Arrhenius type. Pre-exponential term and the apparent activation energy for diffusion were determined by use of the least squares method.
(2) The applicability of the Stokes-Einstein equation was examined. The diffusion coefficient of Ag⁺ ions increases linearly with increasing value of kT⁄ηr, where η is the viscosity of solvent salt. The radius of the silver ion in molten chlorides was considered to be nearly equal to that of the sodium ion.
(3) A linear relation was found between the molar volume of solvent salts and the value of D⁄(T⁄M)^1⁄2 in the temperature range wherein the diffusion coefficients were measured. The diffusive movement of solute cation was considered to be correlated with that of solvent cations.
(4) The polarization energy of anion as well as the energy for hole formation is an important factor controlling the diffusive movement of the solute cation in molten alkali metal chlorides.

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Amorphous superconducting alloys with excellent strength and ductility have been found in rapidly quenched alloys of Nb–Si, Nb–V–Si, Nb–Zr–Si, Nb–Mo–Si, Nb–Ta–Si, Nb–W–Si, Nb–Si–C, Nb–Si–B and Nb–Si–Ge systems. Their continuous ribbons were produced in the form of 1∼1.5 mm width and 0.02∼0.03 mm thickness by using a modified single roller quenching apparatus. The silicon content in these amorphous alloys was limited to a narrow range between about 17 and 21 at%, and the alloy compositions were in the ranges of 0∼20 at% V, 0∼25 at% Zr, 0∼30 at% Mo, 0∼10 at% W, 0∼8 at% C, 0∼12 at% B and 0∼4 at% Ge, respectively. Most of these alloys showed a sharp superconducting transition at a temperature above liquid helium temperature. The transition temperature T_c was in the range of 4.3∼4.4 K for Nb_79∼83Si_17∼21 alloys. This value increased to 6.7 K after crystallization upon annealing. The addition of Mo, C, B and Ge to the Nb₈₀Si₂₀ alloy brought about a slight increase of T_c and the maximum value was about 5.5 K for Nb₅₀Mo₃₀Si₂₀. The upper critical magnetic field H_c2 and the critical current density J_c were of the order of 2×10⁶ A/m in liquid helium and of 1×10⁴ A/cm² in liquid helium at zero field.

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Under creep conditions, cavity growth may be controlled by vacancy diffusion or power-law creep. These two growth mechanisms are examined with reference to a superplastic Al–Zn–Mg alloy, and it is shown that the predicted dominance of power-law growth is consistent with earlier experimental observations of cavitation in this material.

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