Sliding wear of polyetherimide matrix composites: II. Influence of graphite flakes

Sliding wear of graphite flake-filled polyetherimide (PEI) against polished steel counterparts was investigated at various temperatures. The addition of 5–20 vol.% of graphite contributed to an obvious improvement of tribological performance of PEI at either room temperature or elevated temperatures (up to 220 °C). Higher filler content (≥15 vol.%) leaded to a very low coefficient of friction (μ), i.e. around 0.05, when temperatures exceeded 150 °C. Meanwhile, the specific wear rate (image) was also reduced. Microscopy studies suggested that friction films were formed on both the counterpart and the worn surface of composites. An interface layer is supposed to be formed between the friction films at elevated temperature (i.e. 150 °C) for high content graphite-filled PEI composites, which contributes to the unusual improvement of wear properties.