Effect of carbon nanotube addition on friction coefficient of nanotubes/hydroxyapatite composites

Carbon nanotubes/hydroxyapatite (CNTs/HA) composites with different CNTs contents were synthesized by in situ method and were characterized by XRD, TEM and Raman spectroscopy. Friction coefficients of the composites were tested using UMT-2 friction tester. Effect of various factors including CNTs content, testing time and applied load on friction coefficient was carried out. Results show that the CNTs/HA composites exhibited lower friction coefficient than pure HA and their friction coefficients decreased with increase of CNTs content from 0 to 20 wt.%. Addition of CNTs in composite is beneficial to increase wear resistance of the CNTs/HA composite and to decrease its friction coefficient.