Co-Investigator(Kenkyū-buntansha) |
KOMURA Tomomi Alps Electric Co., Ltd. Researcher, 第4製造部, 係長
TAKEUCHI Toshiaki Teikoku Piston Ring Co. Ltd., Researcher, 技術開発部, 主査
YAMAMOTO Masami Research and Development, Kubota Ltd., Researcher, 素形材研究第二部, 社員
MATSUZAKI Kunio Institute for Materials Research, Assistant, 金属材料研究所, 助手 (20181711)
KIMURA Hisamichi Institute for Materials Research, Professor, 金属材料研究所, 助手 (00161571)
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Research Abstract |
Production of Al-based Amorphous Powders and Properties of Their Consolidated Bulk Products In the research for the last two years, it has been clarified that amorphous powders in an Al-Y-Ni system with a particle size-below about 0.025 mm are produced in a high yield fraction of 80 to 90 % by using a high-pressure helium gas atomization technique which was developed by the present researchers. Subsequently, an optimum consolidation process to produce an amorphous bulk from the amorphous powders has been searched. For the last one year corresponding to the final year research program, a warm extrusion to produce an amorphous bulk has been tried for the amorphous alloy powders and the structure, density and properties of the extruded materials have been examined, in order to investigate the possibility of developing a new type of high strength material with light weight. The amorphous alloys were found to exhibit a glass transition phenomenon at temperatures just below crystallization t
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emperature (T_x) in a composition range of 8 to 12 at% Y and 5 to 10 %Ni, accompanied by a significant decrease in viscosity. On the basis of this information, the warm consolidation was tried at temperatures near T_g. As a result, it has been clarified that bulk materials are produced in structural states of a mostly single amorphous phase in the range of 553 to 573 K and coexisting amorphous and crystalline phases in the range of 583 to 603 K. However, the density of the former amorphous bulk is about 98 % and an improvement of extrusion condition is required to produce a more dense bulk material. On the other hand, the latter bulk material with the coexistent structure has a high density above 99 % and the Young's modulus, compressive strength, bending strength and tensile strength are 138 GPa, 1480 MPa, 1360 MPa and 940 MPa, respectively. It is notable that these strengths are 2 to 3 times higher than those of Superjuralmin which has the highest strengths in crystalline Al-based alloys. Accordingly, it is highly expected that a high- strength alloy with light weight is developed by utilizing the Al-based amorphous alloys. Less
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