Microstructural evolutions and mechanical properties enhancement of AA 6063 alloy reinforced with Tungsten (W) nanoparticles processed by friction stir processing

An increase in tensile strength without compromising the ductility is an uphill task in the fabrication of MMCs. This issue can be overwhelmed by the addition of high temperature withstanding metallic nano-particles limiting solubility at elevated temperatures. The present research work concentrates on (a) the development of AA 6063 alloy reinforced with Tungsten nanoparticles (0, 3, 6, 9, and 12 vol%) via FSP, (b) examining the phase analysis using XRD technique, and microstructural evolutions through TEM and EBSD, (c) the improvement in mechanical properties (hardness and tensile strength) and investigate the contribution of strengthening mechanisms, and (d) the work hardening rate, intercept (k) and strain hardening exponents (n) through True stress-strain curves. The results revealed that the uniform dispersion of W nanoparticles is consistent across the stir zone (SZ) of the AA 6063 matrix. Tensile results were witnessed as improvement in UTS with the function of W nanoparticles addition and by elucidating the major loss in ductility. The dispersion strengthening has influenced more to the total strength of the fabricated MMCs due to the pinning effect produced by nano W particles. AA 6063 alloy reinforced with 12 vol% nano W particle specimen has produced superior mechanical properties (Vickers hardness strength of 1.23 GPa, UTS of 432.58 MPa and, elongation of 18.5%.