Solid-state reactions in the 2FeO–SiO₂ and 2NiO–SiO₂ systems were studied using X-ray diffraction, and discussion on kinetics was made comparing the reaction of 2FeO+SiO₂→Fe₂SiO₄ with 2NiO+SiO₂→Ni₂SiO₄.
A sample of mixed powder of 2FeO+SiO₂ was heated and kept at 1173–1323 K for specified times up to 36 ks, and its reaction ratio was determined using the internal standard method of X-ray diffraction. As a result, the solid-state reaction in the 2FeO–SiO₂ system was found to conform to Carter’s equation of diffusion-controlled reaction, and the apparent activation energy of the reaction was about 172 kJ/mol.
A sample of mixed powder of 2NiO+SiO₂ was subjected to solid-state reaction by heating and keeping at 1573–1673 K for specified times up to 100 ks. The reaction ratio of the 2NiO–SiO₂ system was found to be much lower than that of the 2FeO–SiO₂ system and not to conform to any equation of diffusion-controlled reaction. The results of analysis indicated that the solid-state reaction in the 2NiO–SiO₂ system was an interface-controlled reaction, and that its apparent activation energy was about 246 kJ/mol.

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An investigation has been made on the effect of mechanical stirring during eutectic reaction on the structures of hypoeutectic Al-11%Si alloys. Eutectic structures enriched with alpha phase and free silicon crystals formed in the residual liquid are observed with stirring. These phenomena occur remarkably with increase in stirring rate and eutectic reaction time. The mechanism of the morphological change in eutectic structures is discussed, and a model is proposed to explain the mechanism of these phenomena.

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Ductile high strength metallic filaments can be employed as reinforcement for brittle matrices such as fine ceramics. The glass-coated melt spinning of Cr and Co-base alloys was investigated as a means of producing a high strength and high toughness filament. The toughness was estimated from the area of stress-strain curves of the filament obtained. A continuous Cr–Ni–Fe–Si–B filament with a high toughness of 7000 MPa·% was obtained from the molten state at 1600 K for a winding speed up to 7.95 m/s.
Ductile high strength filaments of Co–Mn–Si–B alloys were also successfully produced. A Co₆₈Mn₁₀Cu₂Si₅B₁₅ filament had the highest toughness of 10050 MPa·% with tensile strength of 4740 MPa and elongation of 4.0%. The filament consisted of micrograins with a grain size of 40×10⁻¹⁰ m.

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High modulus carbon fibers without surface treatment were incorporated into aluminum alloys by the squeeze casting process. The chemical interaction between fibers and matrix, and its effects on the composite strength and fracture morphology were investigated. The effects of alloying elements of Cu, Ca and Mg were also investigated.
The strength and modulus of the composites are in good agreement with the values predicted by a simple rule of mixtures. It is found that the shear strength of the composites is improved by Mg and Ca additions to the matrix and by heat-treatment of the composites. The carbon diffused into the matrix in as cast Al–Mg and Al–Ca alloy matrix composites. The shear fracture path is through the fiber-matrix interface in pure aluminum and Al–Cu matrices, and is through the interface region containing alloying elements in Al–Mg and Al–Ca alloy matrices.

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The present work was carried out in order to clarify the heterogeneities in the structure of a commercial PSZ containing 2.5 mol% Y₂O₃ and to observe the microstructural changes with post annealing.
Besides existence of coagulated Al₂O₃ inclusions, it was found that Y₂O₃ concentration in the compact fluctuated in the range from 2 to 3 mol% (the period of the segregated zone was about 5–10 μm). When the compact was annealed at 1673 K, grains in the Y₂O₃ enriched zone (cubic ZrO₂) grew preferentially.
The difference in Y₂O₃ concentration between cubic and tetragonal grains decreased with rising annealing temperature, and they became almost equal in the concentration at 2243 K, eventually. The observation of these annealed structures was carried out by means of SEM and TEM.

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A new technique is proposed for the ceramic lining of a pipe inner surface by means of a thermit reaction under the influence of a centrifugal force (“Centrifugal-Thermit Process”). The technique is characterized by a large amount of the reaction heat and the centrifugal force applied to the reaction products. In the present work, the effect of the centrifugal force and the characteristics of the thermit reaction in the process are investigated to assess its potential and limitation.
With the increase of the centrifugal force, the compressive strength and the apparent porosity of the products were improved. The compression-shear stress and thermal shock resistances were not necessarily improved. The metal and ceramic layers were uniformly partitioned and a dense ceramic layer was obtained under the centrifugal effect of about 200G. However, small cracks were observed in the ceramic layer.
The propagation rate of the thermit reaction was inversely proportional to the thermit powder density. When the technique is applied to a hollow body, the reaction propagated along the inner surface first and into the layer of the reactant subsequently. It is concluded that the Centrifugal-Thermit process proceeds along the inner surface of the hollow body first and then into the layer in the radial direction resulting in the ceramic lining of homogeneous quality.

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The suitability of 6%V Permalloy as magnetic head core materials for use in the digital tape-recording unit of an electronic computer has been investigated with respect to important requirements for the core materials such as effective permeability in a high frequency field, stress-sensitivity in magnetic permeability, wear-resistance and mechanical workability, in comparison with other conventional Permalloys, e.g., 4%Mo Permalloy and 4%Mo-5%Cu Permalloy. V Permalloy examined has a higher ac magnetic permeability in the high frequency range as well as better dc magnetic properties than the compared alloys, in particular at lower annealing temperature below 1073 K. The stress sensitivity of V Permalloy is very low at all annealing temperatures and exciting frequencies so that the value of permeability under stress remains very high. During the process of rubbing against a magnetic tape at a high speed, thin films are formed on the frictional surface of V Permalloy specimen, and V Permalloy is superior in the wear-resistance to the other Permalloys. V Permalloy has the same order of magnitude of mechanical hardness as the other conventional soft Permalloys and has good workability. From these results, it is thought that 6%V Permalloy is superior to the compared alloys for use as magnetic head material.

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