Elsevier

Scripta Materialia

Volume 202, September 2021, 114006
Scripta Materialia

Segregation of alloying elements to stabilize θ′ phase interfaces in Al-Cu based alloys

https://doi.org/10.1016/j.scriptamat.2021.114006Get rights and content

Abstract

Interactions of alloying elements (Si, Mg, Mn, Zr, Zn) and vacancies with coherent interfaces of θ′ phase in Al-based alloys have been systematically studied by means of ab initio supercell calculations. The interface structure with a half-filled interfacial Cu layer is calculated to be lower in energy (by 0.1 eV per structural vacancy) than the structure with a filled Cu layer; the degree of interface reconstruction depends on the availability of vacancies. The presence of vacancies in the interfacial Cu layer plays a crucial role in the interaction of solutes with coherent θ′ phase interfaces. The solute–interface interaction energies are calculated to be much weaker for elements having closed (Cu, Zn) or empty (Mg, Si) d-electron shells than for d-transition metals (Mn, Zr). To clarify the roles of alloying elements and interface structure in the stability of θ′ phase precipitates, we analyze the solute–interface interactions in terms of electronic-structure and atomic-size contributions to interatomic bonding.

Section snippets

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

This work has been financed by the Russian Science Foundation (grant 18-12-00366) and has been carried out using computing resources of the Federal collective usage center Complex for Simulation and Data Processing for Mega-science Facilities at NRC “Kurchatov Institute”, http://ckp.nrcki.ru/.

References (25)

  • A. Biswas et al.

    Acta Materialia

    (2011)
  • C.J. Hung et al.

    Material & Design

    (2020)
  • D. Shin et al.

    Acta Materialia

    (2017)
  • K. Kim et al.

    Acta Materialia

    (2017)
  • S.R. Nayak et al.

    Scripta Materialia

    (2019)
  • O.I. Gorbatov et al.

    Acta Materialia

    (2019)
  • A. Shyam et al.

    Materials Science Engineering A

    (2019)
  • P. Shower et al.

    Materialia

    (2019)
  • L. Bourgeois et al.

    Acta Materialia

    (2011)
  • M.V. Petrik et al.

    Scripta Materialia

    (2019)
  • K. Kim et al.

    Scripta Materialia

    (2019)
  • M. Souissi et al.

    Computational Materials Science

    (2021)
  • Cited by (10)

    • Effect of hydrogen accumulation on θ' precipitates on the shear strength of Al-Cu alloys

      2022, International Journal of Plasticity
      Citation Excerpt :

      The choice of this system is related to its importance for the technological use of aluminum alloys, where copper is very often chosen as one of the basic alloying elements. Besides the structure of the main strengthening phases of this system is well known, although in recent time there are works appeared (Zheng et al., 2020; Bourgeois et al., 2020; Petrik et al., 2021; Krasnikov et al., 2022) devoted to hybridization strengthening phases and their influence on the mechanical properties of alloys. In addition to studying the mechanisms of dislocation-precipitate interaction, works are carried out on the generation of dislocations by such strengthening inclusions.

    • The interplay of precipitation of ordered compounds and interfacial segregation in Al‐Cu‐Hf‐Si alloys for high-temperature strength

      2022, Acta Materialia
      Citation Excerpt :

      The solute atoms (Hf or Si) that reach the plate interface also bring vacancies. These vacancies were readily absorbed by the θ' plate coherent interface, resulting in the binding of solute atoms at the interface [76]. Thus, the presence of these slow diffusing solute atoms acts as a kinetic barrier due to the solute drag effect and delays the coarsening of plates [13].

    • Enhancement in strength and thermal stability of selective laser melted Al–12Si by introducing titanium nanoparticles

      2022, Materials Science and Engineering: A
      Citation Excerpt :

      Even though the Al-based alloys mentioned above demonstrate excellent high-temperature mechanical properties and good thermal stability at the specific temperature range, the selected alloying elements (i.e., Zr, Sc, and Mn) undoubtedly increase their manufacturing costs and complexity of composition control during the preparation of the raw materials [33,35,36]. Moreover, a complex composition of Al alloys can lead to the problem of element segregation and challenging microstructural control upon SLM processing and post heat treatment [37,38]. Thus, the low-cost commercial Al–12Si alloy was chosen as base alloy to design a high-strength aluminum alloy with improved thermal stability at mid-temperature regime.

    • Synergistic effect of joint addition of Sb+Mn on high temperature strengthening in Al–4Cu heat-resistant alloy

      2022, Materials Science and Engineering: A
      Citation Excerpt :

      Another type of micro-alloying elements, such as Sc [17,18], Zr [17,19], and Mn [17,19] are used to improve the heat-resistance of Al–Cu alloy. There are two routes: (1) forming new precipitates with high thermal-stability, such as Al3Sc [20], Al3Zr [21,22] or Al20Cu2Mn3 (T phase) [22,23]; (2) improving the thermal-stability of θ′ phase through forming an atomic layer of Sc, Zr or Mn at the interface of Al/θ′ [19,24,25] that can hinder the migration of Cu atoms. Dorin et al. [26] reported that the increment of the peak-aged strength from the refinement effect of minor addition of Sc + Zr on the meta-stable precipitates of θ′ phase is higher than that from the dispersoids strengthening effect of Al3(Sc,Zr) particles in Al–Cu alloy.

    View all citing articles on Scopus
    View full text