Verification of the phase transformation induced by thermal vacancies in iron aluminides

2015 Fiscal Year Final Research Report

• Project/Area Number: 26889072
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Physical properties of metals/Metal-base materials
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Niitsu Kodai 国立研究開発法人理化学研究所, 創発物性科学研究センター, 特別研究員 (90733890)
• Project Period (FY): 2014-08-29 – 2016-03-31
• Keywords: 金属材料 / 空孔 / 電子線ホログラフィー / 電子顕微鏡 / 点欠陥

Outline of Final Research Achievements

For Fe-Al alloys quenched from high temperatures that contain high density of thermal vacancies, microstructural observation and visualization of the possible vacancy segregation were examined by using an electron holography microscope. As a result, a curious microstructure was observed for a certain concentration region, the nature of which cannot be explained within the understandings on the existing Fe-Al phase equilibrium. However, possible change of mean inner potential attributed to the microsegregation of vacancy was not detected. This is so far believed to be due to its too small signal (less than the signal-to-noise ratio) to be detected, a knockout effect due to high-voltage electron beam, or an over time decay of vacancy.

Free Research Field

材料科学