Talc as friction reducing additive to lubricating oil

Reduction of friction and wear by colloidal suspensions of ceramic powders in lubricating oils is an approach that can allow to formulate environment friendly energy saving lubricants. Commercial talc powder was evaluated as an extreme pressure additive to a lubricating oil under different temperatures and concentrations. The best lubricity was achieved at the temperature of 100 °C and the concentration of 0.15 wt% when dynamic and static friction coefficients were reduced by over 30% in comparison to reference lubricating oil alone. At high temperature, talc forms transfer film on metal surface, which reduce both friction and wear behavior in mating surfaces. However, at room temperature, film formation was not observed. Results are explained using pressure and temperature induced lamellar dehydration mechanism when products of dehydration form oxide transfer films on the friction surface.