CHARACTERIZATION OF HYBRID ALUMINUM COMPOSITES REINFORCED WITH Al2O3 PARTICLES AND WALNUT-SHELL ASH

Hybrid aluminum composites obtained with stir casting were investigated in this study. Aluminum alloy EN AW 6061 was reinforced with particles of Al2O3 and walnut-shell ash (WSA). The weight fraction of Al2O3 was constant (5 w/%) and for the walnut-shell ash, it was (1, 2 and 3) w/%. The morphology of the composites and particle distribution were examined with an optical microscope and scanning electron microscope. Microstructural studies showed a uniform distribution of the reinforced particles in all the investigated samples. A chemical analysis of the reinforcing particles on the samples’ surfaces was done using an energy-dispersive spectrometer. The changes in the mechanical properties including the hardness, tensile strength and elongation in relation to the increase in the weight fraction of ash were investigated. The results showed that the hardness and tensile strength increase, while the elongation decreases with an increase in the weight fraction of ash in the composites. The mechanical properties of the obtained composites showed improvement compared to the EN AW 6061 alloy.