Improved wear resistance in alumina-PTFE nanocomposites with irregular shaped nanoparticles

Past studies with PTFE nanocomposites showed up to 600× improvements in wear resistance over unfilled PTFE with the addition of Al2O3 nanoparticles. Irregular shaped nanoparticles are used in this study to increase the mechanical entanglement of PTFE fibrils with the filler. The tribological properties of 1, 2, 5 and 10 wt.% filled samples are evaluated under a normal pressure and sliding speed of 6.3 MPa and 50.8 mm/s, respectively. The wear resistance was found to improve 3000× over unfilled PTFE with the addition of 1 wt.% nanoparticles. The 5 wt.% sample had the lowest steady state wear rate of K = 1.3 × 10−7 mm3/N m and the lowest steady friction coefficient with μ = 0.21.