Influence of Ultrasonic Vibration towards the Microstructure Refinement and Particulate Distribution of AA7150-B4C Nanocomposites

Aluminum-based metal matrix composites with single or multiple ceramic reinforcements are finding application in the aerospace and automobile industries. In this research work, novel AA7150-B4C (aluminium7150 alloy–Boron carbide) nanocomposites were successfully fabricated, through the liquid metallurgy route via stir casting method, with the incorporation of B4C nanoparticles with different weight percentages using a novel sequence of a vortex technique and a double stir casting process with ultrasonication. The formed composites have been thoroughly studied for microstructure refinement, nano-particulate distribution, and bonding with the matrix by making use of the optical microscopy (OM) and scanning electron microscopy (SEM) studies (respectively). In addition, the composites were analyzed for the density, porosity, and elemental composition. Further, the composites were tested for the investigation of mechanical properties, like micro-hardness and tensile strength, to investigate the influence of ultrasonic vibration on the arrangement of B4C nano-particulates. The analysis indicated that the mechanical properties of the AA7150-B4C nanocomposites in as-cast condition significantly improved with a gain of 57.7% in strength and 24.5% in hardness compared to the native AA7150 material.