Tribological Characterization of Ecodesigned Aluminium Hybrid Metal Matrix Composites

Abstract

Aluminium alloys infused with various reinforcements establish themselves for numerous leading engineering applications. In present study, wear characteristics of Al 7075-T6/Eggshell/SiC/Al₂O₃ hybrid composites (Al 7075-T6 as base metal with three reinforcements eggshell particles wt. % 0.5, 1and 1.5, particle size ~ 55 µm, SiC particles wt. % 1, 1.5 and 2, particle size ~ 70 µm and Al₂O₃ particles wt. % 1.5, 2 and 2.5, particle size ~75 µm) synthesized through electromagnetic stir casting route were studied at various temperatures under dry and lubricated conditions. The wear investigations were conducted on pin-on-disk rotary tribometer Make: Ducom, Atlas; TR-20L-PHM 800-DHM 850 at a constant load of 20N for a sliding speed of 2m/s and sliding distance of 2000 meters. Tribological attributes of synthesized hybrid composites were evaluated as the function of reinforcement contents as per the design of experiment according to Taguchi L9 array. Experimental study showed that at room temperature under dry wear condition, the developed hybrid composites had a maximum decrease of 60% in wear loss while with lubrication the wear was decreased by 89% as compared to the base metal. At an elevated temperature of 70⁰C under dry wear condition, the composite specimens exhibited maximum reduction of 82% in wear whereas under lubricated condition the wear was reduced by 82% in comparison of their unreinforced counter parts. With exceedingly augmented tribological attributes, the current study strongly rationalizes high temperature wear resistant applications of synthesized aluminium hybrid composites with a total reinforcement weight percentage of 4.5% only.