Understanding nucleation/growth mechanism of deformation twins using in-situ picoindentation technique

2015 Fiscal Year Final Research Report

• Project/Area Number: 25420765
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Structural/Functional materials
• Research Institution: National Institute for Materials Science
• Principal Investigator: Somekawa Hidetoshi 国立研究開発法人物質・材料研究機構, 元素戦略材料センター, 主幹研究員 (50391222)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: マグネシウム / 材料工学 / 変形双晶 / 溶質元素 / 結晶粒界 / インデンテーション

Outline of Final Research Achievements

The driving force for {10-12}-type deformation twins nucleation was found to be much higher than that of (basal-type) dislocation formation. The nucleation site for deformation twins in poly-crystalline magnesium is likely to be mainly grain boundary; in particular grain boundary, which has a high grain boundary energy, readily become the nucleation site. The alloying element does not affect the nucleation site, but does the volume fraction of twin formation. These results reveal that grain boundary control, e.g., grain boundary segregation, leads to the prevention or enhancement of twin formation. As for the single-crystalline magnesium, the point defect, such as the vacancy, became the nucleation site for deformation twins.

Free Research Field

材料工学