Tribological Properties of Organic Functionalized ZrB₂–Al₂O₃/Epoxy Composites

The tribological behaviors of epoxy composites filled with organic functionalized ZrB₂–Al₂O₃ were environmentally investigated and compared with those with as-received fillers under both dry and oil sliding conditions in this work. The worn surfaces and the transfer films on the counterparts were characterized by scanning electronic microscope (SEM), and the frictional temperature rising was investigated by infrared thermometer. The results demonstrated that the coefficient of friction (CoF), the wear rate, as well as the frictional temperature rise of the epoxy composites were all decreased due to the introduction of ZrB₂–Al₂O₃ fillers. And with the increase in filler content, similar variation tendencies of CoF and wear rate of epoxy composites were observed under the different sliding conditions. Besides, the organic functionalization of ZrB₂–Al₂O₃ fillers, which made the epoxy composites exhibit lower CoF and wear rate than those with as-received fillers, lowered the frictional temperature as well. In comparison, the epoxy composites filled with 5 vol% modified fillers presented better tribological properties, suggesting a stronger interfacial bonding between modified fillers and epoxy matrix. The dominant wear mechanisms of filled composites under dry and oil sliding conditions could be inferred as the combination of adhesive wear and abrasive wear and the fatigue wear, respectively, on the basis of SEM images of worn surfaces.