Papers by Author: Takeshi Murakami

Paper TitlePage

Authors: Shouichi Ochiai, Takeshi Murakami, Keizo Hashimoto, Nobuo Ishii, Koichi Hasegawa
Abstract: In Pt-10mass%Rh alloys which were recrystallized using full annealing at or above 1273K after the cold rolling with the reduction ratio of both 90% and 98%, the formation of cube texture has already been found. When these primary recrystallized alloys are subjected to the further annealing at higher temperatures, the occurrence of the secondary recrystallization can be expected. In this study, the development of the cube texture and the process in the coarsening of crystal grains during the secondary recrystallization were investigated. In addition, the creep tests were carried out for the secondary recrystallized alloys and resultant creep properties were compared with those for the primary recrystallized alloys. It became clear that the cube texture which further developed during the secondary recrystallization in 98% rolled specimens exhibits the greater thermal stability than that in secondary recrystallized 90% rolled ones. During the secondary recrystallization, it was confirmed that the grains coarsened according to the law of tm, where t and m show time and a constant, respectively. The higher development of the cube texture and the coarsening of grains during the secondary recrystallization were found to have remarkable effects of improving the creep resistance.
Authors: Takeshi Murakami, Shinya Sasaki, K. Ito, Haruyuki Inui, Masaharu Yamaguchi
Authors: Kazuhiro Ito, Taisuke Hayashi, Takeshi Murakami, Masaharu Yamaguchi
Authors: Kiyoshi Ichikawa, Takeshi Murakami, Yukihiro Nakayama, S. Miyamato, Masao Tokita
Authors: Takeshi Murakami, Shouichi Ochiai
Abstract: Grain growth in cube-textured aluminum was investigated by transmission Laue photographs obtained at the same point in specimens with progressing annealing at the heating rate of 20 deg/h. High purity aluminum for electrolytic capacitor was cold rolled to 98 % reduction, and subsequently partially annealed at 230 °C for 6 h and rolled 22 % reduction. On the light rolling, asterisms toward RD were observed near by direct beam, suggesting that lattice rotation around TD was caused in cube grains by light rolling. After annealing to 300 deg, fine Laue spots were detected in the asterisms. Those fine spots were indexed as 100 spots due to diffraction in {100} nearly parallel to the ND-TD plane. After disappearance of Debye arcs due to diffraction in untransformed matrix, cube texture was observed with orientational spread around TD. With continuing annealing to 540 °C , grain growth occurred at the expense of cube grains whose orientations deviated from the exact cube orientation around TD , resulting in sharp cube texture formation.
Authors: Kiyoshi Ichikawa, Takeshi Murakami, Shin-ichi Miyamoto, Yukihiro Nakayama, Masao Tokita
Showing 1 to 10 of 10 Paper Titles