The geometric uniformity on the surface of foils rapidly solidified depends on the roll speed and ejection pressure. The wetting pattern irregularity was fabricated on the roll contact side of foil when the roll speed was low, and that irregularity was eliminated when the roll speed was high. The wetting pattern on the roll contact side surface was consist of the uncontact area and directly contacting area. The uncontact part in the wetting pattern was reduced in size by increasing the roll speed and ejection pressure. The percentage of contact area where the foil contacted to the roll was 70-80% and the contact area increased when the roll speed and ejection pressure increased. The roughness of rotating direction of the roll contact side surface was smaller than that of the lateral direction. The roughness of roll contact side surface decreased with increasing of the roll speed and ejection pressure.

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Rapidly solidified Al-Si alloy foils with Si content in the range of 0-20mass% were prepared by single roll method. Continuous and sound Al-Si foils were fabricated with Si content in the range of 0-16mass%. Dents on the roll contact side surface of foil disappeared when Si content became greater than 4mass%. Good surface characteristics of 99.99mass% Al foil was affected by thickness, but in the case of Al-Si alloys it was not affected. There was no effect on the uncontact part in the wetting pattern by Si content. Roughness on the roll contact side surface of the foil depended on the Si content, and Si content greater than 8mass% made the surface smooth. Contact area between roll and foil increased with increase of Si content within the range of less than 8mass%.

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Alumina/aluminum composites were fabricated by sintering or extruding subsequently mixed powder of a pure aluminum and an alumina. Some mechanical properties, a critical reduction in height in upsetting and changes in the properties after upsetting were investigated for the composites. Although a pure aluminum fabricated from the powder had higher strength than a cast aluminum because of so-called SAP effect, a good wear resistance was obtained only in a composite specimen containing alumina particles. The critical reduction in upsetting at room temperature and 200°C for an extruded billet withou talumina particles was higher than that of a sintered billet. However, in upsetting of billets containing alumina particles the critical reduction, which increased with an upsetting temperature, was little affected by the fabrication process. In upsetting beyond the critical reduction, fine vertical and large zigzag cracks appeared on the surfaces of the billets without and with alumina particles. Before upsetting the hardness of billet extruded at 200°C was higher than that of others, while after upsetting the hardness values of both billets extruded at 200°C and 450°C were almost the same.

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The extrudability of β-SiC whisker or Al₂O₃ discontinuous fiber reinforced aluminum alloy composite billets was investigated in terms of the extrusion shear stress, the whisker or fiber length in extruded bars and the extrusion speed. The extrusion shear stress of composite billets increased with the amounts of whisker or fiber and the shear stress of the matrix alloys. The extrusion shear stress of the composite billets exceeded the limit for the normal extrusion of aluminum alloy billets. The increased extrusion temperature resulted in the decreased extrusion shear stress, but this caused the defect of tearing on the extrusions. Thus, the extrusion condition for composite billets was found to be limited. The break down of whisker or fiber in extruded bars was not improved by decreasing the shearing force during extrusion using conical dies or increased extrusion temperatures. The extrusion speed for composite billets increased up-to more than double of the maximum extrusion speed attained with steel dies by using Si₃N₄ ceramic die or capping thin matrix alloy layer on the leading top of composite billet. These methods were also effective to reduce the extrusion force for composite billets. Thus, these unique methods improved the extrudability of discontinuous fiber reinforced aluminum alloy composite billets.

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Elongation in the tensile test and reduction of cold rolling to failure of Mg-Li and Mg-Zr-Li alloys were investigated. Grain size of α range alloys cast in the same condition was decreased with increasing lithium and the workability of magnesium was improved by the addition of lithium. More uniform deformation and higher rollig reduction to producing deformation band were obtained in the lithium containing magnesium alloys than in pure magnesium. The microcracks were observed in the deformation band. The ductility of magnesium was remarkably improved by the small addition of zirconium. Binary and ternary alloys consisting of (α+β) two phase were extremely superior in ductility to the single α or β phase alloys. It was confirmed that the spheroidizing treatment of the eutectic structure resulted in the improved workability.

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The hydrogen removal from molten pure aluminum and various aluminum alloys by inert gas bubbling using newly developed rotating nozzle was investigated. The dependence of the attainable hydrogen reduction level on the partial water vapor pressure (P_H2O) of 3.4×10^-5 to 1.0×10^-2 atm in ambient atmosphere was studied in molten pure aluminum. The lower P_H2O was, the lower was the attainable hydrogen reduction level. The hydrogen level was lowerd to 0.06cc/100g at P_H2O of 3.4×10^-5 atm for 6min. The attainable hydrogen reduction level in various molten aluminum alloys by the same treatment at P_H2O of 5.0×10^-3 to 2.9×10^-2 atm for 6min, which is usual in japanese weather, was found to range from 0.04cc/100g to 0.13cc/100g. The hydrogen removal was affected by the hydrogen activity coefficient which depended on the molten alloy composition.

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The organic coating adhesion and corrosion resistance of polyacrylic acid-zirconium composite treated aluminum was investigated. The composite treatment solution was composed of polyacrylic acid and zirconium ammonium carbonate. Polyacrylic acid was crosslinked at its carboxyl group by zirconium compound. This reaction produced organic-inorganic composite film showing good organic coating adhesion and corrosion resistance. The most suitable composition of the composite film was obtained from the treatment solution in which weight ratio of polyacrylic acid to zirconium oxide was 1.0. The composite film of this composition showed good coating adhesion and corrosion resistance even after drawing because of its high formability. The formability of the film originated from polyacrylic acid and few defects were generated on the film by forming. Coating adhesion and corrosion resistance of the film was the same as that of unformed chromate phosphate conversion coating. After drawing or heat treatment the former was superior to the latter.

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Alumina coating on carbon fiber by ion-plating method was investigated in terms of a reaction barrier between PAN-based (ungraphitized) carbon fiber and aluminum. The carbon fiber coated directly with aluminum produced carbide (Al₄C₃) on the fiber-aluminum interface and degraded remarkably in strength at temperatures above 723K, while the carbon fiber coated first with alumina and then with aluminum produced less carbide and did not degrade in strength at temperatures up to 823K. These results indicated the availability of alumina coating as a reaction barrier. The alumina coating, however, had no good wettability and bonding ability with aluminum. The alumina coated carbon fiber was additionally coated with aluminum, nickel or titanium to improve these abilities. The aluminum coating improved these abilities without degrading in strength of the fiber after heating, but the nickel and titanium coating caused remarkable degradation in strength of the fibers after heating due to the formation of brittle intermetallic compounds such as Al₃Ni and Al₃Ti.

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