Processing parameters optimization to produce nanocomposite using friction stir welding

Abstract

This paper deals with the fabrication of particulate metal-matrix nanocomposites (PMNCs) reinforced with Al2O3 nanoparticles via friction stir welding (FSW) process. The reinforcement particles (RPs) are incorporated inside the base matrix on abutting edges under different FSW process parameters to achieve maximum joint efficiency. The effect of different parameters namely tool rotational speed, transverse speed, and volume fraction of Al2O3 nanoparticles as input parameters on the ultimate tensile strength (UTS) of the produced nanocomposites has been investigated using the Taguchi methodology. Analysis of variance was employed to obtain the significance of independent variables on overall quality characteristics of friction stir welded nanocomposites. The multi-response optimized variables were found as: tool rotational speed = 2000rpm, transverse speed = 70 mm min−1 and volume fraction of Al2O3 nanoparticles = 0.30%. Based on the optimized parameters, the maximum ultimate tensile strength of the produced PMNCs was 218 MPa. The optimum results obtained using Taguchi method has been validated by conducting confirmation experiments. Macro and microstructural characterization of the produced nanocomposites using scanning electron microscopes revealed that the increase in the amount of heat due to tool stirring action as well as the addition of Al2O3 nanoparticles in the nugget zone leads to improve the interfacial bonding between the reinforcement particles and the base metal matrix and in turn produce the fine PMNCs.