“…The critical content exhibiting the best wear performance has been observed to depend on factors like the nature of the solid lubricant [23,29] and sliding pair material [22,30]. The wear performance was also controlled by the applied load/pressure [24][25][26][27][28], sliding speed [24,26,27] and microstructural features of the samples [22,25,30]. In a few investigations, 3-10% of graphite/talc in oil greatly affected the wear performance of the alloys and composite, while 3-6% of solid lubricant addition to the oil lubricant enabled the specimens to show the best wear performance [22,25,28,29].…”