Experimental investigations on tribological and machining behavior of aluminium hybrid metal matrix composites for automobile brake rotor application

Abstract

Replacing automobile components with the composite materials is a healthy trend in the recent decades due to their enhanced mechanical and tribological properties Grey Cast Iron GCI the existing material widely used in automobile brake rotor application as it has advantages like high hardness and wear resistance Even though GCI has few benefits it also has major shortcomings like high specific weight low mechanical properties (tensile strength impact and shock resistance) and low corrosion resistance In order to overcome these issues and to enhance the wear resistance of brake rotor material the present research work aims to find an alternate for the GCI with an aluminium based hybrid metal matrix composite Among the different robust materials aluminium alloys also offer better physical mechanical and tribological properties so the present work attempts to fabricate an Aluminium 6061-T6 alloy based Hybrid Metal Matrix Composites AlHMMCs reinforced with Alumina, Graphite and Redmud by stir casting method the most viable and effective liquid metallurgy technique among all other fabrication methods In this way Al6061-T6 alloy + 3wt.% Al2O3 +3wt.% graphite composite AlHMMC and Al6061-T6 alloy + 3wt.% Al2O3 + 3wt.% graphite + 3 to 7wt.% Redmud composites RM-AlHMMCs are synthesized The fabricated composites are tested for its density and hardness The results indicate that the density and hardness of 11wt.% Redmud reinforced AlHMMC RM-AlHMMC are 2.21% higher and 19.13% lesser respectively than AlHMMC As the Redmud content increases from 3wt.% to 11wt.% the density of composites increases by 2% and the hardness decreases by 8.49% Similarly the composite specimens are tested for its friction and wear behaviours The experimental results of dry sliding friction and wear tests on Pin on Disc machine reveal that the 11wt.% RM-AlHMMC exposed utmost 90% enhanced wear resistance than AlHMMC As for as Coefficient of Friction CoF is concerned it increases initially with applied load and sliding distance then saturates As a result