Effect of thermal activation on the tribological behaviours of serpentine ultrafine powders as an additive in liquid paraffin

The influence of thermal activation temperature on the tribological properties of surface-coated serpentine ultrafine powders as liquid paraffin additives was studied. It is found that the serpentine powders suspended in liquid paraffin present excellent tribological properties. Thermal activations in a temperature range from 300 to 600 °C increase the film forming ability and tribofilm completeness of the serpentine, keep the layer structure and accordingly further improve the tribological properties. However, the layer structure is destroyed and hard phases appear after thermal activated at or higher than 850 °C, as results in the aggravation of friction and wear.

► Heat treated serpentine powders as additives were studied for the first time.
► Contact resistance was measured to monitor the formation of the tribofilm.
► Thermal activations at proper temperature improve the tribological properties.
► Thermal activations higher than 850 °C aggravate the friction and wear.