Friction Behavior of Hybrid Composites Filled by Titanium Dioxide Nanoparticles

The objectives of the present work are to evaluate the effect of curing times, titanium dioxide nanoparticles and normal loads on the friction coefficient of hybrid composite resin filled by titanium dioxide nanoparticles. Four sets of composite resin specimens are prepared; one without filling material and three sets filled with TiO2 nanoparticles in contents of 0.1, 0.2 and 0.3 wt. %. Composites resin is manually blended with titanium dioxide nanoparticles. Then the mixture is packed into plastic tubes. The specimens are then polymerized from both sides for 10, 20, 40, 60 and 80 seconds using light emitting diode source. To determine the friction coefficient, all specimens are tested with reciprocating sliding apparatus at room temperature. The test conditions are; time = 1 minute, 60 stroke/minute and load = 6, 8, 10, 12 and 14 N. Results show that the friction coefficient is found to decrease with increasing curing time at all values of the normal load. The friction coefficient of the studied hybrid composite is decreased gradually by adding 0.1, 0.2 and 0.3 wt. % of titanium dioxide nanoparticles. Also, friction coefficient of the tested specimens is significantly affected by the normal load. Based on these results, it may be concluded that friction coefficient of the tested specimens is dependent on the curing times, TiO2 nanoparticles content and normal load.