Processing and characterization of in-situ intermetallic and ceramic particles reinforced magnesium matrix composites

The present study aims to investigate the microstructure and mechanical properties of magnesium matrix composites reinforced with in-situ formed Al₃Ti intermetallic and Al 2 O 3 ceramic particles. A novel two-step stir casting technique is used to fabricate a magnesium composite by dissolving a pre-prepared aluminium composite into a magnesium melt. XRD, optical microscopy, and FE-SEM with EDS are used to analyze the in situ-formed particles in the composite. Al 3 Ti, Al 2 O 3 , and other ceramic particles are identified in the composite. Al 3 Ti particles are needle-like, and Al 2 O 3 particles are nearly spherical. Improved hardness but reduced tensile properties are observed in the magnesium composite compared to the cast Mg-9 wt% Al matrix alloy. Fractographic analysis of tensile-tested specimens reveals a mixed-mode failure, predominantly brittle with minor ductile fracture.