Multi-objective optimization of wear and friction behavior of hybrid Magnesium-graphene-silicon nitride composite under dry sliding conditions

The reported work aims to analyse the effect of silicon nitride (Si3N4) on the wear characteristics of magnesium composite processed through liquid metallurgy. The composite is prepared through stir casting under argon atmosphere with varying Si3N4% (5, 10 and 15) and fixed quantity of Graphene Oxide (0.3%). The resistance to wear capability of the prepared composites are tested through pin on disc wear test rig by considering wear parameters like load, velocity and distance. Results indicates that load has greater effect on wear rate followed by Si3N4% whereas and Coefficient of Friction (CoF) is greatly influenced by load followed by velocity. Worn surface of the test specimens exposed reduction in plastic deformation, delamination and cracks with increase in Si3N4%. ENTROPY - COPRAS technique is used for multi objective optimization to get unique optimal parameter for minimal wear rate and CoF. The hybrid method suggests 15 wt.% Si3N4, 1 m/s sliding velocity, 10 N applied load, and 1000 m sliding distance as optimal condition which yields specific wear rate and CoF of 0.9197 x 10-3 mm3/Nm and 0.4019 mu. These conditions can be used for utilizing hybrid composite in dry sliding applications.