Preparation, microstructure and properties of magnesium-γMg17Al12 complex metallic alloy in situ composites

• Published in: Journal of alloys and compounds 2017-04, Vol.702, p.626-635
• Main Authors: Donnadieu, Patricia, Benrhaiem, Souad, Tassin, Catherine, Volpi, Fabien, Blandin, Jean-Jacques
• Format: Article
• Language: English
• Subjects: Chemical Sciences; CMA phases; Eutectic; In situ composite; Mg-Al alloys; Synthesis
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2017.01.294

Magnesium based alloys containing γ Mg17Al12 complex phases have been prepared by solidification. Owing to a methodology based on Scheil Gulliver calculation, a series of composites with controlled volume fraction of γ phase has been obtained. According to SEM and TEM observations, the microstructures of the Mg-γ composites consists in magnesium rich dendrites in various fraction embedded in a eutectic mixture formed by γ phase and Mg rich fibers. Preliminary investigations of the mechanical and electrical behaviors of the composites have been carried out. Microstructures and properties of the Mg-γMg17Al12in situ composite series are discussed with respect to in situ composites containing Bulk Metallic glasses. Multiscale microstructure of the Mg-γ Mg17Al12 complex metallic alloy in situ composites. The composites are characterized by (Mg) dendrites in various fraction embedded in a (Mg)-γ eutectic mixture This eutectic mixture itself consists in a regular array of (Mg) fibers embedded the brittle complex γ Mg17Al12 phase. [Display omitted] •Magnesium based composites containing 20%–60% of complex γ phase were prepared.•Controlled γ phase fractions have been obtained using Scheil Gulliver calculation.•Microstructures consist in Mg dendrites embedded in a eutectic Mg-γ phase mixture.•Remarkably the soft magnesium alloy is always embedded in the brittle complex γ phase.•The Mg-γ composites show a high strength at ambient accompanied by some ductility.