Tribological Performance Evaluation of Hardwood Charcoal Powder Reinforced Polyester Resin with Response Surface Modelling and Optimization

This work examined the tribological performance of hardwood charcoal powder reinforced polyester composites using experimental, response surface modelling and optimization techniques. Dry sliding wear characteristics (weight loss, volume loss, specific wear rate and wear resistance) of hardwood charcoal powder reinforced polyester composites were determined under the conditions of constant load, varying reinforcement particle sizes (75, 150, 250 & 300 µm) and concentrations (5, 10, 15, 20, 25 & 30 wt%). The developed composites exhibited slightly good wear properties at lower reinforcement content and larger particle sizes. Overall best wear properties compared to the unreinforced polyester were given by the 150 µm particle size with a weight loss of 0.0002 g, volume loss of 0.194 mm3, specific wear rate of 0.004 mm3/Nm and a markedly high wear resistance of 25, 257.73 mm/mm3 at 5wt% reinforcement concentration. SEM morphology of the worn surface indicated the existence of strong interfacial interactions and bonding between charcoal particles and polyester resin with micro ploughing and cutting caused by progressive sliding of the abrasive disc on the surface of the composites as the wear mechanism. Process optimization and predictive modelling using response surface method of the design expert version 11.0 revealed the optimal wear process factors and properties with their levels of interactions at a reinforcement particle size of 154.710 µm and volume fraction of 20.451%. Numerical optimization models were also generated for predicting the wear properties at given process factors. The results of this investigation revealed that the developed wood charcoal composites is recommendable for several lightweight structural and tribological applications such as wheels, rollers, clutches, gears, seal cams and other bearing materials.