Tribological and mechanical properties of Al/MoS 2 composite strips fabricated via accumulative roll bonding process

Aluminum matrix composites reinforced with solid lubricants have attracted considerable attention for tribological applications owing to their potential to combine high specific strength with improved friction and wear behavior. In the present work, Al-5 wt.% MoS 2 composite sheets and monolithic aluminum sheets were successfully fabricated through the accumulative roll bonding (ARB) process up to eight passes. The influence of ARB passes on the microstructure, crystallite size, hardness, tensile properties, friction coefficient, and wear behavior of both materials was systematically investigated. Microstructural characterization revealed a significant grain refinement and homogeneous distribution of MoS 2 within the aluminum matrix after repeated ARB processing. The crystallite size decreased progressively with increasing ARB passes, leading to an increase in hardness and tensile strength for both materials. The Al-5 wt.% MoS 2 composite exhibited higher hardness and strength than monolithic aluminum at all processing conditions due to the combined effects of grain refinement and reinforcement strengthening. Tribological investigations showed that the incorporation of MoS. reduced the coefficient of friction compared with monolithic aluminum. However, the wear rate of both the composite and monolithic materials increased with increasing ARB passes. Examination of the worn surfaces indicated that delamination and subsurface crack propagation were the dominant wear mechanisms, particularly after higher ARB passes, where the heavily refined laminated structure promoted layer separation during sliding. The results demonstrate that ARB processing is an effective route for enhancing the mechanical performance of Al/MoS 2 composites, although the associated microstructural evolution significantly influences their wear behavior.