Influence of volume percentage of NanoTiB2 particles on tribological & mechanical behaviour of 6061-T6 Al alloy nano-surface composite layer prepared via friction stir process

The aim of present study is to analyze the influence of volume percentage (vol.%) of nano-sized particles (TiB2: average size is 35 nm) on microstructure, mechanical and tribological behavior of 6061-T6 Al alloy surface nano composite prepared via Friction stir process (FSP). The microstructure of the fabricated surface nanocomposites is examined using optical microscopy (OM) and scanning electron microscope (SEM) for distribution of TiB2 nano reinforcement particles, thickness of nano composite layer formed on the Aluminum alloy substrate and fracture features. The depth of surface nano composite layer is measured as 3683.82 μm along the cross section of stir zone of nano composite perpendicular to FSP. It was observed that increase in volume percentage of TiB2 particles, the microhardness is increased up to 132 Hv and it is greater than as-received Al alloy's microhardness (104 Hv). It is also observed that at 4 volume percentage higher tensile properties exhibited as compared with the 2 and 8 vol. %. It is found that high wear resistance exhibited at 4 volume percentage as-compared with the 2 and 8 vol. %. The observed wear and mechanical properties are interrelated with microstructure, fractography and worn morphology.