1993 Fiscal Year Final Research Report Summary
Electron Beam Melting and Improvement of Mechanical Properties of Pure Tantalum
| Project/Area Number |
04650063
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
機械材料工学
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| Research Institution | Yamanashi University |
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Principal Investigator |
TAKAAI Tetsuya Faculty of Engineering, Yamanashi University, Professor, 工学部, 教授 (80020460)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAYAMA Yoshihiro Faculty of Engineering, Yamanashi University, Assistant, 工学部, 助手 (40227971)
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| Project Period (FY) |
1992 – 1993
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| Keywords | electron beam melting / pure tantalum / refining / yielding behaviors / macroscopic mechanical properties / microscopic mechanical properties |
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| Research Abstract |
Effect of the temperature and strain rate on the tensile yielding and flow of pure tantalum plate, produced by electron beam melting method, was experimentally studied mainly from an engineering viewpoints of fundamental tensile m, mechanical properties and their temperature and strain rate dependency. Sharply projected yielding behaviors were here seen for electron beam melted tantalum under certain specified tensile testing and annealing conditions. Critical temperature for the temperature dependence of the tensile plastic flow was about 0.15 T/Tm which was slightly higher as compared to 0.12 T/Tm of pure tantalum produced by powder metallurgy.
Distinctive brittleness was observed below 250 K regarding the measurements of the uniform elongation for the highest strain rate conditions and ductile to brittle transition was seen for the electron beam melted tantalum at the temperatures ranging from 300 to 250 K.Activation energy and activation volume obtained at temperatures below 380 K in accordance with the yielding or flow of pure tantalum were almost the same as those values measured regarding pure tantalum produced by power metallurgical technology.
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