Tribological enhancement of continuous polytetrafluoroethylene composites interpenetrated by a 3D nickel network and their frictional heat transfer mechanism

Nickel foam (NF) – polytetrafluoroethylene (PTFE) interpenetrating phase composites (IPCs) were prepared by vacuum-assisted emulsion impregnation and free sintering. The effects of the pores per inch (PPI) of NF on the microstructure, mechanical properties, thermal conductivity and tribological properties were investigated. The results indicated that the incorporation of a three-dimensional Ni skeleton inhibited heat accumulation at the friction interface, and the thermal conductivity and wear resistance of the composite significantly improved with increasing PPI. Compared with that of the PTFE matrix, the thermal conductivity of the 80 PPI NF-PTFE IPCs improved by ~ 394%, and the wear rate decreased by up to ~ 66%.