Microstructural, mechanical and corrosion behaviour of B4C/BN-reinforced Al7075 matrix hybrid composites

In this work, significant attention has been given to improve the mechanical and corrosion behaviour of aluminium hybrid metal matrix composites (AHMMCs) of Al7075 with boron carbide (B4C) and boron nitride (BN) as reinforcement particles. The AHMMCs with various weight % (3%, 6%, and 9% by weight) of B4C and fixed weight percentage (3%) of BN particulates were synthesized using the stirring-squeeze cast method. The microstructure images of composites show the grains enrichments. The XRD and SEM studies confirm the formation of intermetallic materials as a secondary phase like Al3BC, AlB12 and AlN in the AHMMCs and better distribution of the reinforcement particles. The improvements in the hardness, tensile, compressive, wear and corrosion resistance of composites were achieved. The enriched grains and intermetallic materials play a predominant role in improving the strength of the hybrid composites. The SEM micrographs of corroded surfaces of the composite reveal that the formation of protective layer supports the higher corrosion resistance of the composites. The study reveals that the B4C- and BN-reinforced aluminium matrix hybrid composites could be a potential candidate for automotive and marine applications.