Title : Effect of dual reinforcement on wear properties of self-lubricating aluminium matrix nanocomposites
The ever increasing demand of various industries for the better tribological properties of the materials led scientists to the selection of novel materials, innovative manufacturing techniques and surface modifications. In the present work, investigations of wear properties of lightweight, self-lubricating aluminium matrix nanocomposites have been carried out. The nanocomposites are manufactured by the spray atomization of molten Al-alloy and ultrasonically co-deposition of graphite and SiC nanoparticles. The agglomeration of the particles, control of porosity, recrystallization rate of the molten alloy were the challenges in the novel process. The process parameters were optimized to obtain the uniformity of particulate distribution and reduce the porosity in the sample. The microstructure and hardness of the samples were examined as the function of SiC particulate content. The tribological properties of the dual reinforcement were examined by the dry sliding pin-on-disk method. The morphological features of the prepared samples and worn surfaces are analyzed by TEM, SEM and EDS. The results depicted that the Al-2% SiC-1% graphite reinforced composite showed the less wear rate compared to Al-1% graphite and Al-alloy due to formation of a stable graphitic layer on the dry sliding surfaces. Further increase in the wear rate and coefficient of friction was noticed with the increase in the SiC content.