Microscopic phase-field simulation of Cr atom substitution character during formation of Ll2 and DO22 phases in Ni-Cr-Al alloy

Springer Science and Business Media LLC - Tập 15 - Trang 588-592 - 2008
Zhong Chu1, Zheng Chen2, Yun-xia Shi1, Yan-li Lu2, Yong-xin Wang2
1School of Mechanical Engineering, Qingdao Technological University, Qingdao, China
2State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an, China

Tóm tắt

The simulations of Cr atom substitution character during the formation of Ll2 and DO22 phases in Ni-Cr-Al alloy were performed at 873 K based on microscopic phase-field model. It is found that the substitution of Cr is affected by Cr and Al contents and limits of occupation probabilities of Cr atom in Ll2 phase are present. The precipitate is single Ll2 phase when the component is less than the limit, Cr atoms substitute the Al sublattices in Ll2 phase, and both of atoms Al and Cr occupy the β-sites and complex phases Ni3(Al1−xCrx) are formed; Cr atoms enter Ni sites when Al and Cr contents exceed the limit, and substitute β-sites or both of α-and β-sites. The DO22 phase is formed at the boundary of Ll2 phase.

Tài liệu tham khảo

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