Validity of log angles (elements of logarithm of rotation matrix) to consider orientation changes in crystals

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K04985
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 26010:Metallic material properties-related
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Onaka Susumu 東京工業大学, 物質理工学院, 教授 (40194576)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 結晶方位 / 転位組織 / 回転行列 / 対数角 / 塑性変形

Outline of Final Research Achievements

Orientation changes are important factors when considering microstructural changes in materials caused by plastic deformation because these are related to the arrangement and density of dislocations. The three elements of a logarithm of a rotation matrix are called log angles, which can be used as a parameter to represent crystal orientations. Experimental results of orientation changes in a cold-rolled Cu bicrystal and ultra-fine grained Al polycrystals are considered to evaluate the validity of the log angles.

Free Research Field

材料科学

Academic Significance and Societal Importance of the Research Achievements

これまでの方位変化の解析はスカラー的な回転角度であるミスオリエンテーション角の評価に限られていることが多く，回転の成分性は情報として活かされていない．回転角の基準軸周りの成分とみなせる対数角は，方位変化解析における重要な変数であり，材料の組織評価に極めて有効である．塑性変形に伴う材料中の方位変化の位置依存性の解析に対数角を応用し，その有用性を実証したことに本研究の学術的な意義がある．