Papers by Author: Hiroshi Anada

Abstract: It was limited to 60/40 brass and the adjustment of grain size was performed, thereafter, it was processed by one way torsion working and back-torsion working. The effect of both workings on the work hardening and the surface roughness of 60/40 brass were investigated. The quenched material has excellent surface roughness in comparison with the furnace-cooled material both after and before workings. It seemed that a little difference in their grain size (15-55μm) affects the restoration ratio of surface roughness. For the back-torsion worked material, as the grain size is coarse, the amount of hardening increases. If the β phase ratio is more, it is easy to become hardened. Inversely, if the β phase ratio is less, it obtains the maximum amount of hardening.

Abstract: It makes use of that excellent nature, high purity aluminum is being used as a function material in the electron, the high technology industry and information. Generally that material is molded as a slab, and processed through such as metal rolling is given after that, and it is being made. It is increase demand that it use for condenser. Condenser capacity is increase by making a (100) oriented cube texture crystal. It is known effective to increase a solid solubility of iron to aluminum that make increase the condenser capacity. Therefore, the cooling rate of Al-10,100 and 1000ppm content Fe was controlled by single roller equipment. Research was done about the relations of the amount of solid solubility of iron to aluminum and the cooling rate. It is result that the amount of solid solubility of iron to aluminum becomes 800ppm at the cooling rate of 2×103 K/s. When the cooling rate rises, the amount of solid solubility increases. The change appears in the separation thing as well because the amount of iron changes by this when the cooling rate is high. When iron is solid solubled in aluminum, it is bigger than the case of solid solubility formed by other general metal elements. Hardness is four times rose more than pure aluminum by solid solubility of iron to aluminum about 800ppm.

Abstract: This study was investigated about that behavior of α phase during recrystallization process and the influence of the amount of strain on semi-solid structure of AC4C aluminum alloy which was processed by one way torsion working. AC4C aluminum alloy billets having a diameter of 35mm and a length of 400mm were torsioned by a single side torsion machine. The maximum strain (γmax) of the specimens in this experiment was 0.88. The specimens were etched for the microstructure observation by optical microscope. The casting material (γ＝0) and the torsion material (γ＝0.73) were remained dendrite structure from room temperature to 565°C. The casting materials had grain-shaped structure when they reached to 585°C which is an eutectic temperature in this alloy. However the torsion working material had it when they reached to 577°C from eutectic temperature on down. In semi-solid region, the structure of the torsion working material was finer than that of casting material and became a more grain-shaped structure. The casting material which was heated to the eutectic temperature was changed to dendrite structure again. However the torsion working material was remained grain-shaped structure.