Dry Sliding Tribological Behaviour of Casted Eutectic Al-Si Alloy with and without Nano Alumina Reinforcement

An investigation on wear behaviour of Al-Si (eutectic) – ENAC48000 have been carried out which are widely employed in the tribological environment as the silicon imparts high wear resistance. Composites with nano alumina (~40 nm) reinforcement of 1%, 2%, 3% (wt %) were prepared using Squeeze casting technique. The samples were polished and grounded well using emery, alumina and diamond paste to study the micro structural morphology using Optical Microscope (OM) followed by SEM. Pin samples were tested for studying the dry sliding wear behaviour using High Temperature Vacuum Tribometer under the load of 10N, 20 N and 30 N at 3.665 m/s. The hardness survey results show a gradually increasing trend in the hardness value with respect to the reinforcement. Regardless of the increasing in the hardness value proportional to the percentage of reinforcement, the wear resistance shows a detrimental pattern as the load and operating temperature increases simultaneously. Abrasion wear mechanism was observed using SEM results on the induced sub surface wear at higher loads. The COF values and mass loss measurement of the composites shows better wear resistance with respect to the reinforcement percentage as the formation of oxide at high temperatures over the surface tends to resist the wear. The results shows promising to employ the composite is low wear working conditions where the thermal distortions due to wear are lesser comparatively.