No abstract

Self-lubricating duplex composites comprising a top layer of polymer-based composites, i.e. bismaleimide (BMI) filled with a wide range of graphite (Gr) content (0-55 wt%), and a bottom layer of infiltrated metal-networks were manufactured by a hot compression-molded method.Melting points and polymerization temperatures of as-received BMI powder and BMI+Gr blends were investigated to determine infiltration process. The polymerization peaks are pushed to higher temperatures with graphite content. For cured polymer composites, the hardness measured by nanoindentation keeps increasing with the graphite content up to 55% without degradation.Tribological performance of the top and bottom composites are examined individually, with focus placed on the development and stability of lubricating transfer film and tribofilm. For the top polymer composites, 25 wt%Gr (or equivalently 17 vol%) is sufficient to form lubricating transfer film and reduces the friction to the lowest ~0.15. For the bottom infiltrated metal-networks, the BMI+55%Gr-infiltrated network is adequate to develop fully covered transfer films and achieve low friction throughout the test. Those results shed lights on design and manufacturing of selflubricating polymer matrix composites on metallic components that undergo severe running conditions.