Extrusion Forming, Microstructure Evolution, and Mechanical Properties of Al Core Reinforced Mg Matrix Composites

Al core reinforced Mg matrix composites are successfully prepared by composite extrusion process. The microstructures of single Mg and Mg/Al composites are characterized and compared. The properties of composites with different volume fractions (Al core) are studied. The strengthening mechanism of composites and the effect of composite extrusion on texture and microstructure are discussed. The research shows that the addition of Al core refines the grains of Mg matrix, but does not change the deformation texture type of Mg matrix. The thickness of Mg/Al interface bonding layer is about 18 μm, and there are intermetallic compounds (Al₃Mg₂, Al₁₂Mg₁₇). As the volume fraction of the Al core increases, the yield strength and compressive strength of the Mg/Al composites are improved. The strengthening effect of Al core on Mg matrix is dislocation strengthening mechanism, fine grain strengthening mechanism, and load transfer effect.