Study about influence factors and mechanism of meso-scale microstructural deformation to achieve active controls of microstructural texture

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H02456
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 26040:Structural materials and functional materials-related
• Research Institution: Toyohashi University of Technology
• Principal Investigator: Kobayashi Masakazu 豊橋技術科学大学, 工学(系)研究科(研究院), 教授 (20378243)
• Co-Investigator(Kenkyū-buntansha): 三浦 博己 豊橋技術科学大学, 工学(系)研究科(研究院), 教授 (30219589) ; 青葉 知弥 木更津工業高等専門学校, 機械工学科, 准教授 (50757143)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 結晶組織 / 局所ひずみ / 集合組織 / 圧延 / 引張 / 三次元

Outline of Final Research Achievements

It is generally difficult to measure internal plastic strain in a deformed metal. In this study, internal plastic strain and microstructures were measured in the polycrystalline metal whose rolling texture is changed with amount of additive elements, by means of 3D/4D non-destructive inspection and analysis of high resolution X-ray CT utilizing synchrotron radiation in SPring-8. By data analysis, we approached controlling factors caused strain concentration and texture change. It was found that the importance is interaction between neighbor grains in aggregated grain structure. We discussed strain concentration and orientation change mechanisms that are related with different property of neighbor grains by using crystal plasticity simulation analysis. Since the factor that can be connected with concentration of internal deformation made clear for metals, the result of this study helps to build the base of method to control texture change positively to give both strength and ductility.

Free Research Field

材料組織解析

Academic Significance and Societal Importance of the Research Achievements

圧延は金属材料の生産工程で常用される手法であり，産業応用上重要なプロセスである。古くから研究も為されている故，多くの研究者が十分理解できていると思っているかも知れない。しかし，実際は単に古典的理論が信じられているのみで，結晶塑性論の示すような結晶粒レベルの変形が圧延集合組織形成へ影響するかどうかは，高度な計測・解析技術が必要となるため調査が進んでいない。計測技術を有した我々が，放射光を利用して，そこにメスを入れ，結晶方位が要因で必ずしも優位な変形を起しているわけではないことを明らかにした。これは新たな結晶塑性理論の発達や集合組織制御に新しい展開を引き起こす引き金となるものである。