Investigations on dry sliding frictional and wear characteristics of SiC and red mud reinforced Al2024 matrix hybrid composites using Taguchi's approach

In this study, frictional and wear behavior of Al2024/SiC/red mud hybrid composites processed by stir casting route has been investigated under dry sliding conditions. Further, influence of parameters, namely red mud fraction (5-20 wt%) and particle size (37-125 mu m), applied load (10-40 N), sliding distance (3000-6000 m), sliding velocity (0.5-2.0 m/s), and their interaction terms on multiresponse characteristics has been examined by employing Taguchi's approach. The wear behavior of hybrid Al composites has been investigated using pin-on-disc apparatus at room temperature and optimization of parameters has been carried by statistical analysis. The adequacy of the developed model has been checked by conducting confirmation experiment and studying the worn surface morphology. The analysis of variance indicates that sliding distance has highest influence (with a contribution of 19.74%) on the wear loss characteristics, while applied load has a maximum contribution of 38.86% in the friction coefficient of the hybrid composites. It has also been revealed that the wear resistance of the hybrid composites is improved with an increase in red mud fraction and decrease in the magnitude of applied load and sliding distance. The morphology of worn surfaces shows that ploughing and abrasion of the wear surface is considerably increased with an increase in the magnitude of wear parameters. But, an increase in red mud fraction reduces the plastic deformation (delamination) of the wear surface since it favors formation of a protective layer between the sliding surfaces. The results of the confirmation experiment indicate that wear loss and friction coefficient of the developed composites have been reduced by 400 and 51%, respectively, in comparison to unreinforced alloy under optimized conditions. The errors in the measurements of the wear loss and friction coefficient have been found to be 4.26 and 2.63%, respectively.