Lubricated Sliding Wear Behavior of a Cast Iron: Effect of Graphite and/or Talc Fraction in Oil

Abstract

The effects of suspended solid lubricant (graphite and/or talc) particles in oil on the sliding wear response of a cast iron have been studied in this investigation. The role played by the changing concentration of the talc and graphite particles added to the oil separately as well as in combination toward controlling the wear behavior of the cast iron has also been analyzed. The investigation strongly suggests beneficial effects of the solid lubricant particles suspended in lubricating oil in terms of decreasing wear rate, frictional heating, and friction coefficient. Interestingly, increasing concentration of the suspended lubricant particles in oil led to reduction in the mentioned properties initially followed by the attainment of the minimum at a specific concentration of the solid lubricants. At still higher concentrations, the trend reversed in the case of wear rate and friction coefficient while it remained unaffected as far as the influence on frictional heating is concerned. Formation of stable lubricating film/layer was noted to be responsible for the improved wear performance of the samples while rupture of the lubricant film led to deterioration in wear behavior.