Mechanical and tribological characteristics of boron carbide reinforcement of AA6061 matrix composite

Abstract

The use of boron carbide-reinforced aluminium matrix composites has grown rapidly in critical applications of aerospace industries, automotive sectors, military, and nuclear engineering. However, boron carbide reinforcement within AA6061 alloy is worthy of investigation in terms of its mechanical and tribological properties. Novel aluminium matrix composites were developed with three different reinforcements (i.e. 5, 10, and 15 wt% of B4C) by using the stir casting process. The developed samples were then tested for performance in terms of mechanical properties (i.e. tensile strength, bending strength, impact strength, shear properties, and micro-hardness). The microstructure of the developed samples was analysed using a scanning electron microscope. By adding 5% B4C reinforcement, the samples display enhanced mechanical properties (high bending, increased resistance to impact test, and shear strength). The micro-hardness tends to increase by increasing the percentage of reinforcement. The novel composites have superior wear resistance due to an increase in the content of B4C particles. The measurements indicate that the wear rate resistance is significantly higher for the composite material with a large amount of B4C particles when was compared with AA6061 alloy. The patterns of surface analysis reveal a homogeneous distribution of ceramic reinforcements in 5 and 15 wt% of B4C samples, as well as a low agglomeration of embedded particles.