Tungsten solubility in L12-ordered Al3Er and Al3Zr nanoprecipitates formed by aging in an aluminum matrix

JOURNAL OF ALLOYS AND COMPOUNDS

卷:820

Article

Farkoosh, Amir R.¹  Dunand, David C.¹  Seidman, David N.^1,2 

[1] Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA

[2] Northwestern Univ, NUCAPT, Evanston, IL 60208 USA

关键词: Aluminum alloys;    Zirconium;    Scandium;    Tungsten;    Atom-probe tomography;   

DOI  :  10.1016/j.jallcom.2019.153383

来源: Elsevier

【 摘 要 】

The partitioning behavior of tungsten is studied in two dilute Al-Er-W and Al-Zr-W alloys aged isochronally up to 400 and 475 degrees C, to form L1(2)-structured Al3Er and Al3Zr nanoprecipitates. Atom-probe tomography reveals low W solubility in the Al3Er and Al3Zr nanoprecipitates (0.071 and 0.234 at.%, respectively) and very low W solubility in the Al matrix (0.057 and 0.023 at.%, respectively), corresponding to precipitate/matrix partitioning ratios of similar to 1-10. First-principles calculations demonstrate that the formation energies of substitutional W atoms in the L1(2) lattices are high and positive (0.66 - 1.73 eV.atom(-1)), consistent with the small W solubilities measured experimentally in these nanoprecipitates. (C) 2019 Elsevier B.V. All rights reserved.

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