Using mixed powder compacts of the Fe-8.0%Cu–C ternary system containing up to 1.5% graphite, and Fe–Cu-1.0%C ternary system containing up to 12.0%Cu, a study of the effect of graphite content on the elimination of the abnormal expansion during the heating process of the Fe–Cu binary mixed powder compacts was carried out mainly by the differential dilatometric method and thermal analysis.
The results obtained were as follows: In both of the mixed powder compacts of the Fe-8.0%Cu–C ternary system with more than 8% graphite, and of the Fe–Cu-1.0%C ternary system with more than 4.0%Cu, a maximum expansion was observed at a temperature slightly higher than 1090°C during heating and then shrank at higher temperatures, and thermal analysis confirmed that the above-mentioned phenomenon is caused by the liquid phase sintering due to the Fe–Cu–C ternary monotecto-eutectic reaction at 1095°C.

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In this report, a conception was proposed to estimate the change in lattice-bond strength due to the presence of hydrogen in some metals.
A practical calculation was made in consideration of the Engel-Brewer theory which is an attempt to correlate the existing crystal structures with the electron configuration and the simple idea that the change in the number of unpaired electrons which take part in metallic bond causes the variation in interatomic bond strength when an electron added by hydrogen is introduced into d-band and s-band.
The tendency of the lattice-decohesion due to hydrogen for some metals estimated on the basis of the conception proposed in this study was in good agreement with that of their solubility of hydrogen, and so it was likely that this conception was of considerable reliability.

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Aging behavior of Al-base alloys containing 0.7∼2.7wt% Li is studied by measuring specific heat vs temperature (S-T) curves during heating of the alloys which have been quenched from 540°C and then aged at various temperatures ranging from room temperature to 300°C for various times. The S-T curves are interpreted by comparing the shapes of the curves of other age-hardening alloys, and an ordering alloy. It is proposed that the precipitation in Al–Li alloys takes place in a five-stage process; solid solution→disordered G. P. zones→ordered G. P. zones→δ″ (short range ordered Al₃Li)→δ′ (long range ordered Al₃Li)→δ(AlLi), during isothermal aging at temperatures below ∼90°C, where, δ″ is a fine particle assumed to be a one- or two-dimensional superlattice of Al₃Li in which only the short range order is developed. The symbol δ′ is restricted to describe only the large particle of a three-dimensional superlattice of Al₃Li. Experimental determinations are made for the stable and metastable solid solubility curves of the δ phase and G. P. zones. A “pseudo-critical temperature” (T_c^′) of δ″ and the critical temperature (T_c) of δ′ are obtained and plotted against the Li content of the alloys. Here, the “pseudo-critical temperature” is the temperature above which the δ″ is considerably destroyed during heating of the alloys.
The δ″ and δ′ phases are already present in the as-quenched state from 540°C, in the case of alloys containing more than 1.7wt% Li.

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The oxygen diffusivities in liquid nickel and iron were measured using the following electrochemical cells of linear geometry: Ni–NiO/ZrO₂(+CaO)/O in liquid Ni(I)/ZrO₂(+CaO)/O in liquid Ni(II) and Mo–MoO₂/ZrO₂(+CaO)/O in liquid Fe(I)/ZrO₂(+CaO)/O in liquid Fe(II). By applying a preselected voltage between thetwo liquid metal electrodes, oxygen in liquid metal(I) was transferred to the right through the right-hand electrolyte. The change of the oxygen concentration in liquid metal(I) at the left-hand interface was followed by e.m.f. measurements between the metal-metal oxide mixture electrode and the liquid metal electrode, in which case the potential was continuously reduced by diffusion of oxygen.
From the e.m.f. change consistent with the theoretical one, the oxygen diffusivity in liquid nickel was calculated to be D₀ (in liquid Ni)=6.3(_−1.4^+1.8)×10⁻⁵ cm²/s (at 1500°C).
The experiments on liquid iron were very difficult because of the internal current, and the diffusivity of oxygen in liquid iron was estimated with a wide confidence range to be D₀ (in liquid Fe)=2.5∼5.5×10⁻⁵ cm²/s (at 1560°C).

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Structural changes during aging of Ni–Cu–Si alloys containing various amounts of Si were investigated by means of transmission electron microscopy and X-ray diffraction. Results obtained are as follows; In an early stage of aging, a periodic phase decomposition occurred along the [100] direction in several Ni–Cu–Si alloys (Ni-40 at%Cu-3∼1.2 at%Si) which had been held at suitable temperatures. The wavelength of the periodic decomposition was observed to be constant for a given composition and temperature during the initial aging.
For high Si alloys or during the low temperature aging, γ′ (Ni₃Si) particles were nucleated coherently on each zone at the end of the constant wave period. These particles increased in size and interparticle spacing as aging progressed and had the regular periodicity and alignment. When the Si content was reduced or after the high temperature aging, typical tweed structures were formed after the [100] phase decomposition. The γ′ particles nucleated on the tweed structure showed two types of distribution, that is, a random distribution and a periodic distribution.

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The elastic energy term, 2η² Y_[hkl], was experimentally measured for single crystals of Ni-37.6at% Cu-6.1at% Si and Ni-36.8at% Cu-7.6at% Al alloys by the pulse echo method using the ultrasonic sound wave, and an influence of the anisotropy of the energy on the metallographic morphology was investigated for the two alloys. The Ni–Cu–Si alloy produces the typical modulated structure having highly aligned zones, while the Ni–Cu–Al alloy forms the mottled structure possessing a more random zone arrangement. Such a morphological difference between the both alloys does not come from a difference in anisotropy of the elastic modulus Y_[hkl], but from a difference in the linear expansion coefficient per unit composition change η. On the Ni–Cu–Si alloy, η and anisotropy of the elastic modulus are large enough to produce the modulated structure, while in the Ni–Cu–Al alloy η is so small that the elastic energy does not make any influence on the morphology of the microstructure, although the anisotropy of the elastic modulus is fairly large.

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The dislocation arrangement in FeAl single crystals compressed at 77, 300 and 473 K has been investigated on the operated (\bar211), (\bar101) and (\bar1\bar12) slip planes by transmission electron microscopy. It is shown that the isotropic invisibility criterion is not applicable to FeAl whose elastic anisotropic factor is larger than that of α-iron but less than NiAl. The observed dislocation arrangement in FeAl strongly depends on the slip planes and the deformation temperature. In the crystals deformed in the [111] antitwinning direction on a (\bar1\bar12) plane, straight, long, screw dislocations are predominant at 77 K and very wavy shape dislocations are seen at 300 K, whereas in the [111] twinning direction on the (\bar211) plane numerous long edge dislocations in irregular shapes are seen besides straight screw dislocations at 77 K and these edge dislocations are still observed in the crystals compressed at 473 K. In the crystals deformed on the (\bar101) [111] slip system, only mixed dislocations are observed.

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A detailed observation of substrate surfaces and oxide scales after oxidation of iron coupon specimens in purified oxygen in a temperature range 973 to 1173 K for varying periods up to 60 ks has been made using a scanning electron microscope.
Many metal ridges and a small number of metal protrusions were formed on the substrate during oxidation. Blistering was also observed during cooling after short oxidation periods at 1073 and 1173 K.
Possible mechanisms for the formation of these ridges, protrusions and blisters have been discussed. It is suggested that there are certain sites where the formation of protrusions and blistering are favoured, and that a partial separation of scale followed by its recontact with the substrate occurs during oxidation.
It is further suggested that for the above oxidation characteristics the behaviour of vacancies transported to the scale/metal interface, oxide growth stresses and oxide plasticity are influential factors.

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The hydrolytic behavior of titanium and zirconium monocarbonitrides at high temperatures has been studied and compared with that of monocarbides and mononitrides of titanium and zirconium.
In the hydrolysis of carbonitride, the gaseous products are found to consist of H₂, N₂, CO, CO₂ and a small amount of CH₄, while liquid fraction involves NH₃ and a very small amount of CH₃NH₂. A remarkable feature for zirconium carbonitride is the formation of NH₃, N₂ and CO in the earlier period of the reaction with the succeeding evolution of CO₂. From measurements of weight changes and by X-ray diffraction it is concluded that a large fraction of carbon precipitates as elementary carbon in the early stage of the hydrolysis and reacts with water vapor in the succeeding stage.
A general relation between the compound under hydrolysis and the chemical species of main primary products is presented; more covalent carbonitrides (such as TiC) have stronger inclination to form N₂ and carbon oxides under hydrolysis and more ionic materials are apt to produce more NH₃ and hydrocarbons.

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The 2H type γ₂′ and 9R type β₂′ martensites in polycrystalline specimens of a Au-47.5at% Cd alloy have been reexamined by means of electron microscopy and diffraction. The major γ₂′ martensite exhibits a spear-like shape and fine bands are observed in it. Crystal structure of the γ₂′ martensite is a modified one with 2H type stacking order, in agreement with the structure determined by Ölander. However, the atomic position of the first layer parallel to the basal plane of the present modified 2H martensite is different from that given by Ölander, that is, the first layer in the present case is stacked at (a⁄2.524, 0, c⁄2). Internal fine bands are unambiguously verified to be twins by taking clear twinned diffraction patterns. The 9R type β₂′ martensite is occasionally observed, which is surrounded by γ₂′ martensites. It has internal stacking faults parallel to the basal plane, and its crystal structure is a modified 9R type one and not the normal one. That is, the first and second layers parallel to the basal plane are stacked at (a⁄2.665, 0, c⁄9) and (2a⁄2.665, 0, 2c⁄9), respectively.

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