Tribological studies on effect of mixture of fillers in polystyrene matrix composites

Abstract

Addition of measured amounts of fillers into a polymer matrix is expected to improve the desired properties of the composites. Also the ease of processability of the matrix and reinforcement is always desired. Use of powder fillers in the polymer matrix at ambient conditions would make the processing much easier. This will help in in situ applications. In the present work, polymer–matrix composites are prepared with polystyrene as the matrix using metal (copper/aluminum/steel) and ceramic (alumina) fillers at ambient conditions. The composites with metallic and ceramic fillers in the ratio of 50:25:25 wt% (polymer:filler 1:filler 2) designated as three-phase composites were investigated for tribological applications. Both copper and aluminum fillers were considered for comparison in terms of their contribution to tribological behavior because of their thermal conductivity, specific heat and density. Polystyrene is filled with metal powder (copper, aluminum or steel) and alumina in equal proportion and subjected to wear and friction tests. The polymer steel–ceramic composite has the least with the other two composites having almost the same values of friction coefficient. The polymer aluminum–ceramic composite has the least wear at all operating conditions. Polymer aluminum–ceramic composite was found to have better wear behavior among the three-phase composites. This may be attributed to the favorable value of density of aluminum, moderate thermal conductivity and excellent specific heat.