Effect of nano-sized TiO2 addition on tribological behaviour of poly ether ether ketone composite

Tribological behaviour of poly ether-ether ketone (PEEK) loaded with different amount of titanium oxide (TiO2) nanoparticles were investigated by pin-on-disk test followed by the characterization of associated transfer film layer (TFL) with the help of nanoindentation. PEEK loaded with 5% TiO2 nanoparticles exhibit lowest specific wear rate in both dry and water lubricated conditions mainly due to the formation of characteristic transfer film layers and water lubrication, respectively. Intrinsic molecular structure of PEEK synergise tribological responses when reinforced with nano-particles. The inbuilt nature of PEEK in contact with water cause matrix relaxation which in turn overshadows the benefit of nanoparticles addition beyond 5% in PEEK composite and overall outcome is the inferior wear-rate of PEEK composites compared to dry tests condition.