Powder metallurgy of Al-based metal matrix composites reinforced with β-Al₃Mg₂ intermetallic particles: Analysis and modeling of mechanical properties

In order to analyze the effectiveness of complex metallic alloys as reinforcing agents in metal matrix composites, Al-based composites were synthesized by hot extrusion of elemental Al blended with different amounts of β-Al₃Mg₂ complex intermetallic particles. The work focuses on two specific aspects: evaluation of the mechanical properties through room temperature compression tests and modeling of the resulting properties. The β-Al₃Mg₂ reinforcement remarkably improves the mechanical properties of pure Al. In particular, the composites with 20 and 40 vol.% reinforcement display yield and compressive strengths exceeding that of pure Al by a factor of 2-3, while retaining appreciable plastic deformation ranging between 45% and 15%. Moreover, the addition of low-density β-Al₃Mg₂ particles significantly increases the specific strength of the composites. Finally, modeling of the mechanical properties reveals that the matrix ligament size plays a dominant role for affecting the properties of the composites.