To investigate interrelations among thermodynamic properties, crystal structures and electronic states in Fe_1−yNi_yTiH_x (where 0<x<1.20; y=0.20, 0.35 and 0.50), pressure-composition isotherms (PCT curves), X-ray diffractographs and Mössbauer spectra of these hydrided compounds have been measured. Clear correlations are found between the formation enthalpies, lattice parameters and isomer shifts of β hydrides of the above compounds and Ni or H concentration. The thermal stability of these hydrides which increases with the Ni concentration is related to the chemical interaction between Fe and H atoms that is enhanced by Ni atoms in the hydrides.

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A series of [001] tilt grain boundaries in TiO₂ (rutile) has been studied using a polarizable point ion shell model. The energy as a function of misorientation angle consists of peaks and cusps. Cusps occur at the (230), (120), (130) and (150) interfaces and others correspond to peaks. Especially the (120) and (230) boundaries have low energies. The (001) projections of calculated equilibrium configurations of these boundaries are also shown. The rutile structure makes these boundaries quite different from the interfaces in NiO which has a simple structure (rock salt) compared with rutile. The results obtained are discussed in terms of monopole fields acting on ions and also the reciprocal density of coincidence sites of ions (Σ). It is found that boundaries with Σ-values smaller than 39 correspond to cusps in the diagram of energy versus misorientation angle, while peaks comprise of boundaries which have large values over 51 for Σ. This fact suggests that the boundary energy is related directly to the reciprocal density of coincidence sites in the case of TiO₂.

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Thermal cycling effects in an aged Ni-rich Ti–Ni shape memory alloy have been examined by means of differential scanning calorimetry (DSC) and transmission electron microscopy (TEM), changing aging temperature and time, temperature range for thermal cycling, and the number of thermal cycles up to 10⁴ times. Two kinds of thermal cycling termed “complete cycling” and “incomplete cycling” were adopted: The complete cycling caused the B2 matrix\ ightleftarrowsrhombohedral intermediate (R phase)\ ightleftarrowsmonoclinic martensite (M) transformations in the appropriately aged alloy, and the incomplete cycling did only the first B2\ ightleftarrowsR transformations. The DSC measurement revealed that the complete cycling significantly affected not only the R→M transformation temperature, M^*, but also the B2→R one, T_R^*, of the aged alloy, M^* being lowered to a great extent whereas T_R^* being raised up considerably. Meanwhile, the R→B2 reverse transformation temperature, T_R^r*, was raised like wise with T_R^*, and the M→R reverse one, A^*, was lowered a little. On the other hand, the incomplete cycling brought about substantially no change in the transformation temperatures. The TEM observation on the aged alloy subjected to the complete cycling of 10⁴ times showed that the B2 matrix regions between the Ti₃Ni₄ precipitates were heavily roughened by some lattice defects. However, the TEM observation on the alloy subjected to the incomplete cycling showed no change. The observed decrease in M^* and increase in T_R^* are discussed standing on a point of view that stress fields around the precipitates formed during aging may be relaxed by the thermal cycling.

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The magnetic field-induced transformation from paramagnetic austenite to ferromagnetic martensite in an Fe-3.9Mn-5.0C (at%) alloy has been studied by means of magnetization measurement, differential scanning calorimetry and optical microscopy, applying a pulsed ultra high magnetic field. As a result, the followings were found: Transformation temperature, M_s′, shifts from the M_s temperature by a magnetic field, and the amount of the shift, ΔM_s=M_s′−M_s, increases linearly with the critical magnetic field for inducing the martensitic transformation. Irrespective of ΔM_s, the amount of magnetic field-induced martensites increases with the maximum strength of magnetic field and the martensite morphology is the same as that of thermally-induced ones. A thermodynamical analysis suggests that the effect of a magnetic field on the transformation from paramagnetic austenite to ferromagnetic martensite in the Fe–Mn–C alloy is due only to the Zeeman effect, being different from that on ferromagnetic austenite to ferromagnetic martensite in other ferrous alloys, where the high magnetic field susceptibility and forced volume magnetostriction are also effective.

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The internal friction of sintered ultra-fine aluminium products (SUFAP) has been measured in an inverted torsion pendulum apparatus. A relaxation peak of a thermal activation type is observed at about 400 K. A possible mechanism for the peak is suggested; grain boundary sliding of fine grains of aluminium with some contribution of the diffusional relaxation along oxide or nitride particles. The results are compared with a mechanical property of SUFAP measured in a previous study.

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Non-uniform multiple slip near a grain boundary plane in face centered cubic bicrystals was examined analytically. Mathematical models for movement and interaction of dislocations were introduced to have a quantitative constitutive relation describing plastic deformation of face centered cubic crystals. Then, a new computer code for finite element structure analyses based on the relation was developed. By applying the code to deformation analyses of isoaxial bicrystals of the nominal strain incompatible type, the formation process and the structure of shear strain in the multiple slip region were examined. Results are summarized as follows:
(1) Very early in the activation of secondary slip systems, shear strain on the systems is on the order of 10⁻⁷ and it is about 1/100 of that on the primary system.
(2) At the deformation stage when the nominal strain is about 12 times as large as that at the elastic limit, the multiple slip region consists of a rather uniform distribution of shear strain on the primary slip system and non-uniform shear strain on the secondary systems. The latter strain ranges from 10⁻⁷ to a value comparable to that on the primary system.
(3) When the interaction intensities between moving and forest dislocations are doubled, the propagation rate of the multiple slip region and shear strain on the secondary systems are reduced to about 1/1.6 and 1/2, respectively.
(4) The propagation rate of double slip is about 1/30 of the rate of single slip. This ratio does not depend significantly on the interaction intensity of dislocations.

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Addition of 0.2 kmol/m³ ammonium acetate, along with 0.1 kmol/m³ boric acid, to nickel acetate/formamide, nickel acetate/N-methylformamide and nickel acetate/N, N-dimethylformamide baths resulted in nickel electrodeposits having a high degree of hardness. Further, the addition of a small amount of cobalt acetate was found to be highly effective in enhancing the hardness as well as improving the surface appearance of nickel deposits. The presence of ammonium and cobalt ions was highly influential in improving the hardness. Nevertheless, the basicity and dielectrical properties of amide solvents were highly instrumental in deciding the grain refinement of electrodeposited nickel. Peeling due to the internal stress of the electroplates obtained from a nickel acetate/formamide bath disappeared totally when they were annealed at 473 K. Scanning electron micrography revealed refinement in grain size with successive inclusion of methyl group in formamide.

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Thermodynamic properties of the liquid In–Bi–Pb alloys have been determined from galvanic cell measurements on five pseudobinary systems of fixed N_Bi⁄N_Pb molar fraction ratio. The cell used were as follow:
(−)In, In₂O₃|ZrO₂(+Y₂O₃)|In–Bi–Pb, In₂O₃(+).
The emf measurements were carried out in the temperature range of 923–1123 K. The activies and the partial molar properties of indium were determined from the experimental data. From the partial properties of indium the excess integral properties of the ternary alloys were calculated by means of Darken’s method, the activities of bismth and lead were calculated by using Gibbs-Duhem equation. The excess free energies of the ternary alloys are slightly positive in the composition range of N_Bi<0.1 and exhibit negatively large values as the molar fraction of bismuth increases.
The ternary excess free energies calculated from related binary data by means of Kohler, Toop, and Jacob and Fitzner’s equations which are based on the regular approximation do not agree with the experimental results. By assuming the pseudobinary systems of fixed N_Bi⁄N_Pb to be regular solutions, a new equation for predicting ternary excess free energies were derived. The calculated ternary excess free energies from this equation agree well with the experimental results.

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Microstructural aspects of rapidly solidified Al-10∼60 at%Mg ribbons prepared by the single roller method were examined by X-ray diffraction analysis, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The lattice parameter of the aluminum rich phase increases with magnesium content up to 35 at% indicating the extended solid solubility, whereas the maximum equilibrium solubility is equal to 18.9 at% at 723 K (eutectic temperature). As-quenched ribbons (20-34.3 at%Mg) comprised supersaturated solid solution, α, and a new metastable phase, X. 42 at%Mg ribbons consisted of the X phase only and 60 at%Mg ribbons were single phase of equilibrium γ.

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