The internal friction of deformed niobium has been measured in a torsion pendulum over a temperature range from −190°C to +300°C. By annealing with zirconium foils, the oxygen and hydrogen contents of niobium can be reduced considerably. For such specimens, no α-peak has been observed after deformation. Subsequent cathodic charging of hydrogen introduces the α-peak. Therefore, the presence of hydrogen is considered to be essential for the occurrence of the α-peak.
The addition of deuterium also introduces the α-peak at nearly the same temperatures as in the case of hydrogen-charged specimens. In view of a large difference in the diffusivities of hydrogen and deuterium in niobium, the atomsphere dragging may not be the rate-controlling process for the α-relaxation.

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For obtaining a more exact kinetic description of the capillary penetration of liquids, the usual equation of motion of liquids in capillary tubes was modified by considering the change of contact angle between the capillary wall and the liquid surface. Using the derived kinetic equation, the penetrating rate of water into glass capillary tubes and also the rate of molten copper into the iron capillary tubes were directly computed after the Runge-Kutta method. The calculated relation between the rising height of liquid in the capillary tube and the time agrees well with the experimental result, and the intensive effect of the time dependent contact angle on the rising process of liquids into the capillary tubes was confirmed.

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The Kozeny-Carman equation was modified by considering the time dependency of contact angle between the capillary wall and the liquid surface in order to describe more precisely the infiltration rate of liquid into a porous body. The validity of the derived rate equation was proved in comparison with the experimentally measured rates of infiltration of water and some metal infiltrants into the sintered porous glass and metals respectively. The infiltration rate was not influenced considerably by the change of the contact angle during the infiltration, and the use of the average or constant value of contact angle was proper for the computation of the infiltration rate.

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The ordering and phase separation in the Fe–Al alloy have been investigated on the basis of the pairwise interaction model. The tendencies toward the ordering and phase separation are proved to be caused by the effect of interactions between the 3rd neighboring or farther atoms in addition to the 1st and 2nd neighboring ones. In the Fe–Al alloy on the iron-rich side, the three kinds of phase separation into α and B2, α and DO₃, and B2 and DO₃ are demonstrated to occur besides the ordering of the B2 and DO₃ types. The equilibrium phase diagram of the Fe–Al system proposed by the present calculation agrees well with previous experimental results.

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It has been observed that the metals which exhibit anomalous diffusion behaviour are all allotropic in nature. A hypothesis to rationalise this interrelationship between the diffusion behaviour and the phase transformation characteristics is discussed here. This relationship arises from the correspondence between the saddle-point configuration of the diffusing atom and the structure of an allotrope of the matrix. Thus, in the embryonic form, the saddle-point configuration represents the structure of the matrix after the phase transformation. Several characteristics of the anomalous diffusion behaviour can be explained with the help of the present suggestion. Further, an estimate of the diffusion rates for several metals made on the basis yields satisfactory agreement with the experimental results.

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Interdiffusion coefficients in copper-rich copper-tin solid solutions containing up to 6 at% of Sn have been determined by Matano’s analysis in the temperature range between 973 and 1101 K using semi-infinite couples with Kirkendall markers consisting of pure copper and Cu–Sn alloys. An anomalously large Kirkendall effect reported by several authors has been shown to be an overestimation resulting from the disregard for the large difference in partial molar volumes between Cu and Sn in the alloy. Using the data on the interdiffusion coefficient, the marker shift, the partial molar volumes and Darken’s relation, the intrinsic diffusion coefficients, D_Sn, and D_Cu, in the Cu-alloys containing 0.9, 1.7, 3.1 and 4.9 at% of Sn have been determined, and the ratio of D_Sn⁄D_Cu has been found to be about three. In addition to the above experiments with semi-infinite couples, the intrinsic diffusion coefficients in the Cu-alloys containing 0.6, 1.4, 2.6 and 3.5 at% of Sn at 1089 K have been determined by Heumann’s method using finite thin plate couples. Using the tracer diffusion data in pure Cu and the value of D_Cu in the infinite dilution of Sn evaluated from the detailed concentration dependence of D_Cu thus obtained, the vacancy flow factor which is expressed by the ratio of the phenomenological coefficients of flux equations in the infinite dilution of Sn, (L_CuSn⁄L_SnSn)_NSn=0, at 1014 and 1089 K, has been estimated to be −1.06_−0.24^+0.18 and −0.84_−0.13^+0.12, respectively. Such a negative large ratio suggests that the jump between a tin atom and a vacancy in copper is strongly correlated.

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By means of the transmission electron microscopy the dislocation structure was studied on β-CuZn single crystals deformed at room temperature.
Results obtained are as follows.
(1) Primary dislocations were distributed uniformly and in a planar arrangement. In the low strain range long wavy dislocation dipoles deviated ∼0.50 rad from the edge component and the lack of screw dislocations were the typical structures.
(2) As the deformation proceeded, cusps, debris and small loops were generated on the screw dislocations.
(3) Even at the highest strain studied (ε=0.40), there were few three-dimensional dislocation networks because the secondary dislocation density was extremely low.
(4) Between the flow stress, τ and the dislocation density, N, there was the relation τ=τ₀+αGbN^1⁄2; (τ₀: the friction stress, α: the numerical constant, G: the shear modulus, and b: the strength of superlattice dislocation). α=∼0.3 was obtained.

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In order to clarify the mechanism of austenite decomposition at elevated temperatures, 25Cr–20Ni steel cold-rolled to 0∼60% reductions in area was aged at 1073 K for various times up to 10.8 Ms. According to the experimental results obtained by means of optical and electron microscopy, magnetic powder pattern, magnetic analysis and electron diffraction, metastable ferrite which is difficult to infer from the phase diagram precipitates from the austenite satisfying the Kurdjumov-Sachs orientation relationship. Although a larger amount of acicular ferrite forms in the cold-rolled specimen as compared with as-solution treated one, it is observed only in the recrystallized regions. It is considered that the most of such ferrite particles found in the present study transform finally to the σ phase after prolonged aging times.

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