Atom Probe Tomography Study of Fe Segregation at Phase Interface in Zr–2.5Nb Alloy
来源期刊：Acta Metallurgica Sinica2019年第10期
论文作者：Xue Liang Qiang Li Jiao Huang Mei-Yi Yao Hui Li Qing-Dong Liu
文章页码：1281 - 1286
摘 要：β-Nb is a typical second phase in Zr–Nb-based alloys used as fuel claddings in water-cooled nuclear reactors. The segregation of alloying element Fe may affect the corrosion resistance of Zr–Nb-based alloys. In this work, the Fe segregation at the interface between β-Nb phase and α-Zr matrix in Zr–2.5 Nb alloy was studied using atom probe tomography and focused ion beam. The results suggested that the Fe concentration was much lower than Nb concentration in α-Zr matrix, while Fe selectively segregated at the β-Nb/α-Zr phase interface, leading to a Fe concentration peak at some interfaces. The peak Fe concentration varied from 0.4 to 1.2 at.% and appeared at the position where Zr concentration was approximately equal to Nb concentration. The selective segregation of Fe should be affected by the heat treatment and structure defects induced by cold rolling.
Xue Liang1,2，Qiang Li1,2，Jiao Huang3，Mei-Yi Yao1,2，Hui Li1,2，Qing-Dong Liu4
1. Institute of Materials,Shanghai University2. Laboratory for Microstructures,Shanghai University3. School of Materials Science and Engineering,Inner Mongolia University of Technology4. School of Nuclear Science and Engineering,Shanghai Jiaotong University
摘 要：β-Nb is a typical second phase in Zr–Nb-based alloys used as fuel claddings in water-cooled nuclear reactors. The segregation of alloying element Fe may affect the corrosion resistance of Zr–Nb-based alloys. In this work, the Fe segregation at the interface between β-Nb phase and α-Zr matrix in Zr–2.5 Nb alloy was studied using atom probe tomography and focused ion beam. The results suggested that the Fe concentration was much lower than Nb concentration in α-Zr matrix, while Fe selectively segregated at the β-Nb/α-Zr phase interface, leading to a Fe concentration peak at some interfaces. The peak Fe concentration varied from 0.4 to 1.2 at.% and appeared at the position where Zr concentration was approximately equal to Nb concentration. The selective segregation of Fe should be affected by the heat treatment and structure defects induced by cold rolling.
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