2020 Fiscal Year Final Research Report
Development of environment-friendly as-cast Ti alloys both by simplifying the manufacturing process and expanding the alloy compositional area
Project/Area Number |
18K11712
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Multi-year Fund |
Section | 一般 |
Review Section |
Basic Section 64030:Environmental materials and recycle technology-related
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Research Institution | Hiroshima University |
Principal Investigator |
Matsugi Kazuhiro 広島大学, 先進理工系科学研究科(工), 教授 (30253115)
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Co-Investigator(Kenkyū-buntansha) |
崔 龍範 広島大学, 先進理工系科学研究科(工), 准教授 (00457269)
佐々木 元 広島大学, 先進理工系科学研究科(工), 教授 (30192595)
許 哲峰 広島大学, 工学研究科, 特任助教 (70620863)
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Project Period (FY) |
2018-04-01 – 2021-03-31
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Keywords | 鋳放し使用Ti合金 / 合金設計 / 浮揚溶解 / 合金元素戦略 / 低コストチタン合金 / 省エネルギー製造プロセス |
Outline of Final Research Achievements |
In order to develop a high-performance β-type Ti alloys in the as-cast state, the composition was proposed in the phase boundary diagram using the electronic parameters Bo and Md. The compositions were proposed by estimating the characteristics from the degree of solidification segregation and deformation behavior, and the microstructure was controlled by the only CCLM / solidification process. The price of the commercial 15-3-3-3 alloy for complicated post-treatment can be expected to be reduced by about 40% by omitting post-treatment. Developed by alloy design and microstructure control. The as-cast alloy has the same characteristics as the commercial alloy, and an energy saving effect of 35% was obtained. For example, Ti-5Cr-5Mn-2.5Zr-2Fe and Ti-10.5Cr-5.4Mn-2.4Zr-1Al alloys had yield stress of 950MPa, tensile strength of 1030MPa, fracture elongation of 10% or more, and higher corrosion resistance, compared with commercial 15-3-3-3 alloy.
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Free Research Field |
材質制御
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Academic Significance and Societal Importance of the Research Achievements |
Ti合金最終コストは、原材料費用を1、鋳造費が0.5、後処理が1.5となり、航空機用途の場合、2次加工費は2と推定でき、後処理簡素化が急務である。しかし単一の鋳造プロセスのみで組織・材質制御までを達成することは、有史以来例をみない。鋳放し状態では元素の凝固偏析、非平衡相の出現、構成相の不安定性、組織構造の不健全性が問題となる。金属学・材料開発が提唱されて以来、高性能化には希少金属元素の合金化と製造プロセスの複雑化で対応してきた。ユビキタス元素多用、製造プロセス簡素化は、製造プロセス原理と合金化学の相関をマルチスケールで解明して理論化すると言う集大成でのみ成就でき、目下の環境保全にも最適である。
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