Microstructural and Mechanical Behavior of Unique Aluminum Matrix Composites Reinforced with Pre-Synthesized Al/Cu Core-Shell Particulates

In this study, Al matrix composites (AMCs) reinforced with Al/Cu core-shell particles were synthesized by hot pressing. The Al/Cu particulate reinforcements were pre-synthesized by galvanic replacement. The effect of the volume fraction of reinforcement on the microstructure and mechanical behavior of the composites was investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), micro-hardness and compression tests. The strength of the composite becomes 2.25 times the matrix by using 20 vol.% core-shell reinforcements con-taining only 6 vol.% Cu. Further, with increasing volume fraction of Al/Cu reinforcement, the degree of in-situ transformation of Cu into intermetallic also increases. Consequently, a specially tailored microstructure can be obtained by controlling the volume fraction of the reinforcement and its interfacial reaction with the matrix, which can improve the mechanical strength of composites without considerably compromising on fracture strain. The findings of this work provide stronger implications for the industry to fabricate viable engineering structures.