Quantitative microanalysis in the analytical electron microscope and its application to the construction of alloy phase diagrams.
Project/Area Number |
62460195
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Research Category |
Grant-in-Aid for General Scientific Research (B)
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Allocation Type | Single-year Grants |
Research Field |
金属材料(含表面処理・腐食防食)
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Research Institution | Kyushu University |
Principal Investigator |
NEMOTO Minoru Faculty of Engineering, Kyushu University, Professor, 工学部, 教授 (90005265)
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Co-Investigator(Kenkyū-buntansha) |
HORITA Zenji Faculty of Engineering, Kyushu University, Research Associate, 工学部, 助手 (20173643)
SANO Takeshi Faculty of Engineering, Kyushu University, Research Associate, 工学部, 助手 (70037810)
MIURA Yasuhiro Faculty of Engineering, Kyushu University, Associate Professor, 工学部, 助教授 (80037879)
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Project Period (FY) |
1987 – 1988
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Project Status |
Completed (Fiscal Year 1988)
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Budget Amount *help |
¥8,300,000 (Direct Cost: ¥8,300,000)
Fiscal Year 1988: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1987: ¥7,900,000 (Direct Cost: ¥7,900,000)
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Keywords | Analytical electron microscope / Quantitative microanalysis / Extrapolation method / Differential X-ray absorption method / k-factor / Ion-milling / Ni-Al-Ta合金状態図 / Ni-Al-Mo三元合金 / Ni-Al-Ta三元合金 / Al-X二元合金 / イオンミリング / 特性X線強度比 / 吸収補正 / 膜厚測定 / ニッケル合金状態図 / 超耐熱合金 / 合金元素の分配 |
Research Abstract |
This study is concerned with the quantitative microanalysis of thin samples in the analyti-cal electron microscope equipped with an energy dispersive spectrometer and its application to the construction of phase diagrams in Ni-based alloys. For accurate and precise quantification, it is important to use the k-factors which are determined experimentally rather than calculated theoretically. This is because the theoretical equation cannot describe changes in the sensitivity for X-ray detection. The X-ray absorption in the sample leads to a significant error in quntification but this can be corrected simply by using the extrapolation method and the diferential X-ray absorption method, both of which do not require measurement of the thickness in analysed regions. An experiment shows that the depth distribution of X-ray production is almost constant across the thickness of Ni thin sample. Thus, this effect is considered to be negligible on the quantification Ni-base alloys. Because the formation of surface layers which are rich in X-element in Al-X (X=Si,Cu,Ag) alloys, an error may be introduced in the quantification particularly for thinner regions. The effects of such surface layer can be reduced by ion-milling or by the use of the extrapolation method. Determination of the Ni-Al-Ta ternary phase diagrams at lower temperaures results that the gamma/gamma' two phase area expands to the region of higher Ni concentration. This is different from earlier results obtained by EPMA method in SEM. It is found that, in the gamma/gamma' two phase regions of the Ni-Al-Mo ternary system, Mo is more partitioned into gamma' phase than gamma phase when the total amount of Mo is small. However, with an increasing addition of Mo, partitioning behavior is reversed. Mo is more contained in gamma phase than gamma' phase. Similar behavior is observed for Ta in the Ni-Al-Ta ternary system.
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Report
(3 results)
Research Products
(19 results)