Impact of recovered silicon particles incorporation on tribo-characteristics of a poly ether ether ketone polymer composite

The tribological behaviour of polyether ether ketone (PEEK) polymer filled with various concentrations of recovered silicon particles (0, 1, 3, 5, and 10 wt%) fabricated by the hot press technique was investigated in this research work. The hardness and wear properties of the prepared composite materials were evaluated through the Shore D hardness and the pin-on-disc methods. The Shore D hardness of the PEEK composite containing 10% silicon was about 95. This was due to the silicon's better dispersion influencing hardness enhancement. The current study found that adding 10% recycled silicon to PEEK decreased the rate of wear to 0.77*10⁻⁶ mm³/Nm and the coefficient of friction (COF) to 0.06. PEEK composites are filled with 10% silicon particles. Silicon particles were responsible for elevating wear resistance and anti-friction behaviour compared to pure virgin PEEK. The wear-behaviour of the PEEK/Silicon composite was greatly influenced by the formation of a transfer film, which avoids direct contact between countersurface steel asperities and the composite. The lubricity effect was obtained by incorporating silicon particles in the PEEK matrix as sliding surfaces with a steel counter surface that tend to form iron oxide and passive hydration mixed transfer films, decreasing COF and wear considerably. The tribofilm firmly adheres to the counter disc through the mechanical interlocking of silicon particles, enabling higher tribofilm bond strength.