Tribological properties of α-, and β-manganese dioxide/polytetrafluoroethylene composites under the dry sliding condition

Nano-sized α-manganese dioxide (α-MnO2) and β-manganese dioxide (β-MnO2) powders synthesized by a hydrothermal approach were employed to improve the tribological property of polytetrafluoroethylene (PTFE). The wear resistances of α-MnO2/PTFE and β-MnO2/PTFE composites are both far better than that of the original PTFE. Compared with α-MnO2/PTFE composite, β-MnO2/PTFE composite always exhibits a better wear performance. Of all the α-, and β-MnO2/PTFE composites, the composite with the β-MnO2 addition of 10 wt% shows the best tribological properties, due to the existences of the uniform PTFE-based transfer film and the continuous worn surface of this composite produced during the friction process.