2021 Fiscal Year Final Research Report
Enhanced compressibility of ultrafine-grained semi-solid two-phase aluminum alloys
| Project/Area Number |
19K04079
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 18010:Mechanics of materials and materials-related
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| Research Institution | Doshisha University |
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Principal Investigator |
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| Project Period (FY) |
2019-04-01 – 2022-03-31
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| Keywords | 超微細結晶材料 / 加工性 / 強ひずみ加工 |
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| Outline of Final Research Achievements |
Ultrafine grained materials or nanocrystalline materials should have high formability under high compressive stress state because they have low strain hardening capability due to their unique deformation mechanism involving grain boundary sliding. Target materials was changed from semi-solid Al-Si alloys to copper of commercial purity because it was difficult to fragment the second Si phase by ECAP for Al-Si alloys, which is essential to obtain high formability.
However, it was found that even pure copper have high potential to exhibit high compressive formability.
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| Free Research Field |
材料工学
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| Academic Significance and Societal Importance of the Research Achievements |
構造材料の高強度化は構造物の軽量化を可能とするため，省資源かつ省エネルギーに対して重要な課題である．強ひずみ加工法は大型の構造用金属材料に対して結晶粒径をサブミクロンまで微細化することが可能であり，かつ合金元素を必要としないために将来的には重要な強化手法となりえる．一方で、本手法においても強度化に伴い破断伸びの低下し，二次加工性の低下も課題であった．しかし、超微細材料がもつ局部延性はくびれが発生しにくい，圧縮応力状態では従来材にそん色ない加工性を示しことが実証された．加工性方法をうまく選択すれば高い二次加工性を得られることが示されて，構造用材料への適用できる可能性が他かくなった．
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