The cooling water used in vertical aluminum DC casting is generally induced to just under the mold to prevent molten aluminum break out. However, the cooling water leaks into the air gap between the mold and the surface of ingot, so water splashes over the top of the molten aluminum, resulting in uneven cooling. But the quantitative survey on the splash break behavior and the change in the cooling condition has not been conducted. Hence, to quantify the splash break condition and the cooling capability, we have made the “Cooling water simulator” capable of freely controlling the potential splash causing factors such as temperature of cooling water, water flow rate, air gap amount, and angle of the water flow, reproducing the splash, and measuring the heat transfer value. The experimental result reveals that the temperature of cooling water is not a factor highly influencing on heat flux and splash, but the splash behavior highly depends on three factors which are the water flow rate, the angle of water flow, and the distance between the cooling water hit point level and the cooling water exit level. And that the heat flux also increases when splash occurs. In addition, the splash break parameter was drawn based on the above three factors, and the correlation between splash break parameter and heat flux was clarified. Use of splash break parameter enables setting of the casting condition where the maximum heat flux is obtained while preventing splash.

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Aluminum has been dissolved by corrosion approach making use of phenol as a solvent and aluminum chloride as a catalyst for a period of 2.1 ks refluxing process. White aluminum oxide powder was successfully obtained when the solution has been hydrated and dried in electric oven. The powder derived from our approach above was evaluated in comparison with aluminumphenoxide reagent. When the powder was sintered at 1473 K for 3.6 ks, the apparent α-alumina was confirmed by XRD analysis, which showed completely same XRD patterns of the aluminumphennoxide reagent. It was found that the shape of our α-alumina powder was a few micron meter size hexagonal scales. From electrochemical point of view, the dissolution of aluminum in phenol was explained as the corrosion phenomena of aluminum.

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The effect of iron content of Al–Mg–Si alloy strips fabricated by the twin roll cast (TRC) on filiform corrosion resistance after paint was investigated. The filiform corrosion resistance was maintained to 0.4 mass% iron content. However, the resistance was deteriorated on 0.8 mass% iron content. The deterioration of the filiform corrosion resistance of Al–Mg–Si alloy with 0.8 mass% iron was related to the intermetallic compounds included iron. Higher amount of iron in Al–Mg–Si alloy made the intermetallic compounds formed on cell boundary during twin roll casting. The intermetallic compounds are found to be the origin of corrosion, and corrosion progress along the compounds. As a result, the continuous intermetallic compounds are decreased of filiform corrosion resistances on TRC strips.

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Carbon fiber reinforced aluminum alloy composites (CF/Al composites) are expected to be applied to electric power cable due to superior specific strength and specific modulus. It is reported that CF/Al composites form aluminum carbide (Al₄C₃) at the interface between carbon fiber and aluminum alloy. However, in operating condition (300°C, 36 years), the growth of Al₄C₃ and tensile strength of CF/Al composites have not been clarified. In this study, at first, pitch-based CF (XN-60)/Al composites are fabricated with ultrasonic infiltration method and held at 300, 450, 500°C for a given length of time. Secondary, influence of holding temperature on the quantity of Al₄C₃ was investigated. Thirdly, relationship between the quantity of Al₄C₃ and tensile strength of CF/Al composites was examined. As holding temperature increased, the quantity of Al₄C₃ increased and tensile strength decreased. Reaction kinetics calculation indicated that remaining strength versus theoretical strength (ROM) of the CF/Al composites, held at 300°C for 36 years, was 0.81. That is, it should be better for applying the pitch-based CF/Al composites to electric power cable than the PAN-based CF/Al composites.

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Pressureless infiltration of molten magnesium into the [Al₂O₃+Ti] blended powder preform was attempted at 700°C in order to fabricate magnesium matrix composites. The titanium powder as an infiltration aid was mixed with the Al₂O₃ powder to improve wettability. Effects of Al₂O₃/Ti volume ratio, relative density of the preform and Al₂O₃ particle size on the pressureless infiltration behavior and mechanical properties of the composites were investigated. Molten magnesium did not infiltrate into Al₂O₃ powder preform at all. The spontaneous infiltration took place by adding a certain amount of titanium powder in the Al₂O₃ powder preform. When the relative density of the preform increased, more titanium fraction was necessary for the spontaneous infiltration. Decreasing the Al₂O₃ particle size made the spontaneous infiltration difficult. The hardness and the compressive strength became higher as Al₂O₃/Ti volume ratio or relative density of the preform increased. By using the finer Al₂O₃ particles, the mechanical properties were improved as well.

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