Fabrication of Al7075-B4C-fly ash hybrid nanocomposites by ultrasonic assisted stir casting and tensile analysis

Abstract

Metal matrix composites reinforced by nano-particles have become appealing materials, ideal for numerous uses. Such composites incorporate a metal matrix reinforced with nano-particles offering physical and mechanical properties distinctive from the ones from the matrix. The nano-particles may enhance the properties of the matrix material regarding the wear resistance, damping properties and mechanical strength. Varieties of metals, such as Al, Mg and Cu, are generally utilized for the fabrication of composites reinforced by nano-ceramic particles such as carbides, nitrides, oxides and carbon nanotubes. The most crucial concern intended to produce them consists in the poor wettability of the reinforcement particles in the matrix alloy that fails to encourage the production by traditional casting techniques. Different ways seem to have been provided by the researchers for producing of the nano-composites. The current investigation is targeted at the production of the Al7075 hybrid nanocomposites reinforced with 1.5wt.% B4C and 0.5, 1.0 and 1.5 wt.% fly ash nanoparticles, using a hybridised production route consisting of the stir casting accompanied by the ultrasonic processing of the nanoparticles to get a unique hybrid nanocomposite with homogeneous dispersion of the nanoparticles in the matrix. The fracture analysis of the tested specimens using scanning electron microscopy (SEM) shows ductile fracture. The mechanical properties of the HNCs are enhanced. So, the use of fly ash as the hybrid reinforcement is successful in producing a low cost and low density, high strength HNCs.