Metallurgical Synthesis Methods for Mg-Al-Ca Scientific Model Materials

Metallurgical and Materials Transactions A, vol. 56, pp. 546–556

Abstract

Abstract Further improving the mechanical and corrosion properties of Mg-based alloys requires the investigation of underlying causalities between synthesis, processing, and microstructure, ideally down to the near atomic scale. However, such investigations with high resolution characterisation techniques require model materials of exceptionally controlled chemical composition and microstructure. In this context, the Mg-Al-Ca system, being attractive for offering significant improvement of the inherent brittleness of Mg alloys, is exceptionally challenging from a metallurgical perspective due to the inclusion of components with high reactivity and vapor pressures. Here, we demonstrate the applicability of various synthesis methods from arc-melting over solution growth to diffusion couples, extending to parameters for thermomechanical processing. Suitable pathways to overcome the specific challenges of the Mg-Al-Ca system are demonstrated, as well as the persistent limitations of the current state-of-the-art metallurgical laboratory technology. Solid solution sheet or wrought materials are ideally produced by induction melting in steel crucibles and casting under elevated pressure, with intermittent annealing steps between hot rolling passes to ensure homogenous chemical composition without excessive grain growth. Composite microstructures strongly depend on the solidification rate, and special care needs to be taken with regards to crucible reactions with increasing Al concentrations. Binary intermetallic compounds can be successfully produced in bulk by a variety of techniques, but the interplay between reactivity and evaporation of the melt when both Ca and Al are present required more complex approaches such as the Bridgman method for the synthesis of ternary compounds.

Authors 13

1. W. Luo Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University, Sustainable Ferrous Metallurgy, Intzestrasse 10, 52072, Aachen, Germany

2. L. Tanure Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University, Sustainable Ferrous Metallurgy, Intzestrasse 10, 52072, Aachen, Germany

3. Markus Felten Aachen Corrosion and Corrosion Protection

   RWTH Aachen University

   Affiliation as printed

   Corrosion and Corrosion Protection, RWTH Aachen University, Intzestrasse 5, 52072, Aachen, Germany

4. Jakub Nowak Aachen Corrosion and Corrosion Protection

   RWTH Aachen University

   Affiliation as printed

   Corrosion and Corrosion Protection, RWTH Aachen University, Intzestrasse 5, 52072, Aachen, Germany

5. W. Delis Aachen Institute of Physical Metallurgy and Materials Physics

   RWTH Aachen University

   Affiliation as printed

   Institute of Physical Metallurgy and Materials Physics, RWTH Aachen University, Kopernikusstrasse 14, 52074, Aachen, Germany

6. Martina Freund Aachen Institute of Physical Metallurgy and Materials Physics

   RWTH Aachen University

   Affiliation as printed

   Institute of Physical Metallurgy and Materials Physics, RWTH Aachen University, Kopernikusstrasse 14, 52074, Aachen, Germany

7. Nadia Ayeb Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University, Sustainable Ferrous Metallurgy, Intzestrasse 10, 52072, Aachen, Germany

8. Daniela Zander Aachen Corrosion and Corrosion Protection

   RWTH Aachen University

   Affiliation as printed

   Corrosion and Corrosion Protection, RWTH Aachen University, Intzestrasse 5, 52072, Aachen, Germany

9. C. Thomas

   Forschungszentrum Jülich · Ernst Ruska Centre

   Affiliation as printed

   Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, Wilhelm-Johnen-Straße, 52428, Jülich, Germany

10. M. Feuerbacher

    Forschungszentrum Jülich · Ernst Ruska Centre

    Affiliation as printed

    Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, Wilhelm-Johnen-Straße, 52428, Jülich, Germany

11. S. Sandlöbes-Haut Aachen Institute of Physical Metallurgy and Materials Physics

    RWTH Aachen University

    Affiliation as printed

    Institute of Physical Metallurgy and Materials Physics, RWTH Aachen University, Kopernikusstrasse 14, 52074, Aachen, Germany

12. Sandra Korte‐Kerzel Aachen Institute of Physical Metallurgy and Materials Physics

    RWTH Aachen University

    Affiliation as printed

    Institute of Physical Metallurgy and Materials Physics, RWTH Aachen University, Kopernikusstrasse 14, 52074, Aachen, Germany

13. Hauke Joachim Springer corresponding Aachen

    Max-Planck-Institut für Nachhaltige Materialien · RWTH Aachen University

    Affiliation as printed

    Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Strasse 1, 40237, Düsseldorf, Germany

    RWTH Aachen University, Sustainable Ferrous Metallurgy, Intzestrasse 10, 52072, Aachen, Germany