▎ 摘　　要

This study compared thermal and tribological properties of multilayered graphene-based flyash filled and banana fiber reinforced brake friction composites with graphite-based specimens. Two series of brake friction composites by varying the content of graphene/graphite (1, 2, and 3 wt%) were manufactured and tribo-evaluated using a pin-on-disc type tribo-tester. Tribological properties of the brake friction composites were studied at varying test conditions of normal load (50 and 150 N) and sliding velocity (3.3 and 9.9 m/s). Compared to graphene, the thermal stability remains higher for graphite lubricated composites and decreases with increased graphite/graphene loading. The developed graphite/graphene brake friction composites resulted in a reduction in friction coefficient with increasing sliding velocity and normal loads. The graphene-filled composite exhibited higher friction performance with enhanced wear resistance at lower sliding velocity than graphite-based composites. The friction performance of graphite-filled composites and the graphene-filled composite's wear resistance remains highest at higher sliding velocity conditions. Moreover, it is observed that the wear rate of graphene lubricated composites remains 21%-35% lowers than the graphite-filled composite. Finally, the worn composite surfaces were analyzed using a scanning electron microscopy to study the possible wear mechanisms and to understand the nature of the formed contact patches/plateaus remain vital for deciding the tribological behavior of the composites.