4.7 Article

Formation of hypoeutectic structure and strengthening mechanism of Co4Cr1.5Fe1.5Ni5 high entropy alloy alloyed by Al

期刊

JOURNAL OF ALLOYS AND COMPOUNDS
卷 923, 期 -, 页码 -

出版社

ELSEVIER SCIENCE SA
DOI: 10.1016/j.jallcom.2022.166372

关键词

High entropy alloy; Phase formation mechanism; Strengthening mechanism; Mechanical properties; Interface barrier strength

资金

  1. National Natural Science Foundation of China [51825404]
  2. Postdoctoral Foundation of Heilongjiang Province [LBH-Z19154]
  3. National Natural Science Foundation of Heilongjiang Province [LH2020E031]

向作者/读者索取更多资源

By investigating the AlxCo4Cr1.5Fe1.5Ni5 alloys, the phase formation and strengthening mechanisms were revealed. The microstructure of the alloy changes from single FCC phases to FCC and BCC phases with the increase of aluminum content, which is consistent with the predicted phase diagram. The tensile strength of the alloy is attributed to interface strengthening and solid solution strengthening. The study provides insights into optimizing the microstructure and mechanical properties of the alloy.
To reveal the phase formation mechanism and the strengthening mechanism, the AlxCo4Cr1.5Fe1.5Ni5 alloys (x = 1.0, 1.2, 1.4, 1.6, 1.8, 2.0) were prepared by arc melting. Phase formation and prediction, tensile properties, strengthening mechanism and deformation mechanism were researched in detail. Results show that the microstructure of AlxCo4Cr1.5Fe1.5Ni5 alloys changes from single FCC phases (x <= 1.4)) to FCC and BCC phases (x>1.4), which was in good agreement with the calculated phase diagram (CALPHAD) prediction. The lower mixing enthalpy of Ni-Al leads to the segregation of Al element at the inter-dendritic region, which promotes the formation of BCC and FCC lamellar structure in hypoeutectic Al2Co4Cr1.5Fe1.5Ni5 alloy. The ultimate tensile strength of Al2Co4Cr1.5Fe1.5Ni5 alloy is 835 MPa, meanwhile the fracture strain is 31.8 %. The tensile strength of Al2Co4Cr1.5Fe1.5Ni5 alloy is attributed to the interface strengthening and the solid solution strengthening. The massive cross slip of dislocations in primary FCC phases and the dense dislocations blocked by the FCC-BCC interface increase the tensile strength. The interface barrier strength of the BCC-FCC interface in Al2Co4Cr1.5Fe1.5Ni5 alloy was estimated to be 3.9 GPa, which shows the higher barrier strength than conventional BCC-FCC interfaces. Coupled effects of the primary FCC and the lamellar structure of FCC and BCC phases will maintain good mechanical properties. (C) 2022 Published by Elsevier B.V.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.7
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据