1992 Fiscal Year Final Research Report Summary
Development of Ni-Al Base Shape Memory Alloys with Enhanced
| Project/Area Number |
02555144
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
金属材料(含表面処理・腐食防食)
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
NISHIZAWA Taiji Tohoku Univ.Fac.of Eng.Professor, 工学部, 教授 (60005212)
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| Co-Investigator(Kenkyū-buntansha) |
SHUGO Yoshiro Daido Steel Co., New Mater. Res.Lab., Researcher, 新素材研究所, 主任研究員
KUSAKA Katsuji Daido Steel Co., New Mater. Res.Lab., Assistant Manager, 新素材研究所, 副所長
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| Project Period (FY) |
1990 – 1992
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| Keywords | Shape memory effect / Ni-Al base alloys / B2 structure / Llo structure / Transformation temp / Ductilization / Intermetallic compound / Thermoelastic martensite |
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| Research Abstract |
In order to develop the Ni-Al base shape memory alloys with enhanced ductility, the hot workability, microstructure, shape memory effect and mechanical properties in the Ni-Al-Fe, Ni-Al-Mn and Ni-Al-Fe-Mn systems were investigated. The results obtained are as follows :
(1) A small amount of fcc phase formed by the addition of Fe and Mn has a drastic effect not only on the hot workability but also on the tensile ductility at room temperature. The enhancement in ductility is mainly due to the modification of beta-phase grains by the coexistence of phase.
(2) Ductile shape memory alloys based on the bate phase matrix in the Ni-Al-Fe, Ni-Al-Mn and Ni-Al-Fe-Mn systems have been developed by promoting the formation of fcc phase in the grain boundary of matrix phase. The two-phase beta+gamma alloys show high degree of shape recovery, which depends on the volume fraction of the phase. Normal pseudo-elastic behavior above Ms is not detected unambiguously in these alloys.
(3) The transformation temperatures can be controlled by adjusting the annealing temperature in the beta+gamma two-phase region. The maximum operating temperatures for shape memory alloys in the Ni-Al-Fe and Ni-Al-Mn systems are 150ﾟC and 700ﾟC, respectively.
(4) Although these alloys have not shown in the complete shape recovery, they are attractive for the new type of shape memory alloys which operate at rather high temperatures.
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