| Project/Area Number |
17K14836
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Structural/Functional materials
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| Research Institution | Doshisha University |
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Principal Investigator |
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| Research Collaborator |
MIYAMOTO Hiroyki
FURUKAWA Ryo
MAJIMA Masasige
MAULIDI Muhammad Lutfi
SARR Mouhamadou Moustapha
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| Project Period (FY) |
2017-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2018: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
Fiscal Year 2017: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
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| Keywords | マグネシウム合金 / 腐食 / 強ひずみ加工 / マグネシウム / 耐食性 / 組織 / 構造・機能材料 |
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| Outline of Final Research Achievements |
Corrosion resistance of ZK60 alloy and pure Mg processed by equal channel angular pressing (ECAP) was investigated using immersion tests in 5 wt% NaCl aqueous solution. The corrosion rates of ECAPed ZK60 alloys increased by increasing number of ECAP passes. Potentiodynamic polarization curves suggested that cathodic reaction was activated, and a passive film formed during immersion tests was weakened by increasing ECAP passes. This can be due to increasing intermetallic compounds and dislocation density during ECAP process. After heat treatment at 623 K for 1.5 h, the corrosion rates were significantly reduced by the heat treatment.
In contrast, the corrosion rate of pure Mg decreased after 1 pass ECAP and gradually increased after 2 pass ECAP. The grain size of ECAPed pure Mg was smaller than that of no-ECAPed pure Mg. Increasing the pass number, the grain size increased. After heat treatment, the corrosion rates increased. This can be due to the grain growth by heat treatment.
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| Academic Significance and Societal Importance of the Research Achievements |
マグネシウム合金は、輸送機器用の軽量材料として高いポテンシャルを有している一方で、腐食しやすいことが問題となっている。本研究では、強ひずみ加工により、マグネシウム合金の組織を制御することにより、その耐食性を組織の観点から制御できる可能性を見出した。強度や加工性といった機械的性質と耐食性をバランスできる加工技術へと展開でき、輸送機器の軽量化による安心安全社会と低炭素社会の実現へとつなげたい。
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