Characterization of physical and mechanical properties of aluminium based composites reinforced with titanium diboride particulates

摘要

Particulate reinforced aluminium matrix composites are one of the most attractive approaches for applications where high strength and hardness combinations are necessary. The aspiration of this study is to investigate the effect of titanium diboride addition on physical and mechanical properties of Al2024-TiB2 composites manufactured using stir casting route, by varying the weight percentages (wt.%) (0, 3, 6 and 9 percent) of titanium diboride particulates. During the casting process, stirring time and speed were kept constant and same for all the composites. Microstructural analysis demonstrates uniformity in TiB2 distribution and also strong matrix-reinforcement bonding which can be as a result of magnesium addition and preheating of titanium diboride particles before incorporating into the molten aluminium. With an increment in the wt.% of TiB2 particulates, hardness and tensile strength of the prepared composites improved, a significant improvement in hardness as well as tensile strength is encountered in Al2024-9% TiB2 composite, which is 44.94% and 35.49% higher than Al2024 matrix alloy, respectively. SEM analysis of the fractured surfaces revealed that the mode of fracture of unreinforced material is purely ductile but reinforced material fractured by nucleation of cracks and plastic deformation.