On the sliding wear of nanoparticle filled polyamide 66 composites

The tribological properties of polyamide 66 (PA66) composites, filled with TiO2 nanoparticles, short carbon fibres, and graphite flakes, were investigated. Sliding tests were performed on a pin-on-disk apparatus under different contact pressures, p, and sliding velocities, v. It was found that nano-TiO2 could effectively reduce the frictional coefficient and wear rate, especially under higher pv (the product of p and v) conditions. In order to further understand the wear mechanisms, the worn surfaces were examined by scanning electron microscopy and atomic force microscopy. A positive rolling effect of the nanoparticles between the material pairs was proposed which contributes to the remarkable improvement of the load carrying capacity of polymer nanocomposites.