| Co-Investigator(Kenkyū-buntansha) |
NAKAO Yoshikuni Osaka University,Faculty of Engineering,Professor, 工学部, 教授 (20029086)
ATARASHIYA Koji Hokkaido University,Faculty of Engineering,Associate Professor, 工学部, 助教授 (80001204)
SUGA Tadatomo University of Tokyo,Advanced Science and Technology Research Center,Associate Pr, 先端科学技術研究センター, 助教授 (40175401)
ISEKI Takayoshi Tokyo Institute of Technology,Faculty of Engineering,Professor, 工学部, 教授 (10016818)
ISHIDA Yoichi University of Tokyo,Faculty of Engineering,Professor, 工学部, 教授 (60013108)
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| Research Abstract |
This project was composed of seventeen individual research works on metal-ceramic joining, which can be conventionally classified into the following three categories; joining reaction processes, joined interfaces, and mechanical properties of joints. Materials used were Al, Cu, Mo, Nb, Ni, V, W, or their alloys as metallic materials, Al_2O_3, AlN, MgO, PSZ, Si, Sialon, SiC, Si_3N_4, TiB_2, ZrB_2, Diamond as ceramics, and pure metals, and Al, Cu, or Ag-Cu Alloys containing active metals as filler metals. Combining these materials. Metal-ceramic systems with or without fillers were joined and examined for structure and properties of joined interfaces. Results obtained are as follows: (1) In joining reaction processes study, formation and growth mechanisms of reaction layer by vapor metallization, effects of shape and treatment of the surface of ceramics on the residual stress of joints, effects of specific additives to ceramics on the bond strength, crystallographic relationships between
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ceramic and reaction layer, effect of specific additives to filler metals on the thickness of reaction layer, effects of applied electric field on the segregation of active metals in the filler, control of wettability by changing the amount of active metals in the filler, and effect of surface conditions on the wettability to the filler, were studied. (2) In joined interface study, useful pieces of information on crystallographic coherency, atomic structure, relaxation of residual stress, and behavior of lattice defects were obtained mainly by high resolution transmission electron microscopy, as well as theoretical consideration from atomistic and electronic points of view. (3) In the study of mechanical properties of joints, available methods for relaxation of residual stress by insertation of functionally gradient materials, metallization, control of the thickness of reaction layer, and two step joining were realized, as well as improvement of analysis for interfacial stress by molecular dynamics and modeling, and also of measurement of the stress by ultrasonic microscopy. Less
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