In the aerospace, energy, construction, and related sectors, there has been an
increasing demand since the early 1960s for materials that are both stiffer and
stronger, yet lightweight. It is not possible to satisfy all engineering requirements
with monolithic materials, neither in terms of properties nor in terms of the
diversity of desired characteristics. Composites, which combine multiple
materials with distinct properties into a unified whole, enable the realization of
high-performance application objectives and requirements, as they can be
designed and engineered according to the desired properties. This provides a
direct illustration of the dependence of technological advancement on material
improvements. Aluminum-based alloys and composites find widespread use as
engineering materials. Strength, thermal stability, toughness, oxidation
resistance, and resistance to wear and creep are often primary targets when
reinforcing composites with an aluminum matrix. In recent years, aluminum
matrix composites (AMCs) reinforced with discrete particles have attracted
considerable research interest due to their exceptional properties and broad
industrial applicability. The Al-Mg₂Si composite has the potential to replace
conventional Al-Si alloys and Al-SiC/Al₂O₃-type AMCs. In the Si-Mg system, the
intermetallic compound Mg₂Si forms as discrete particles, exhibiting
outstanding physical and mechanical properties such as low density, high
melting temperature, high hardness, high elastic modulus, and low coefficient
of thermal expansion. Moreover, Mg₂Si is non-toxic, corrosion-resistant,
environmentally friendly, and a cost-effective semiconducting compound. Such
composites are fabricated through straightforward casting processes, wherein
the Mg₂Si strengthening phase forms in situ during solidification as a result of
elemental interactions.
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