The mechanical properties and dry sliding wear behaviour of glass fabric reinforced epoxy (G-E) composite with varying weight percentage of silicon dioxide (SiO2) filler have been studied in the present work. The influence of sliding distance, velocity, and applied normal load on dry sliding wear behaviour has been considered using Taguchi's L9 orthogonal array. Addition of SiO2 increased the density, hardness, flexural, and impact strengths of G-E composite. Results of dry sliding wear tests showed increasing wear volume with increase in sliding distance, load, and sliding velocity for G-E and SiO2 filled G-E composites. Taguchi's results indicate that the sliding distance played a significant role followed by applied load, sliding velocity, and SiO2 loading. Scanning electron micrographs of the worn surfaces of composite samples at different test parameters show smooth surface, microploughing, and fine grooves under low load and velocity. However, severe damage of matrix with debonding and fiber breakage was seen at high load and velocity especially in unfilled G-E composite. 1. Introduction Present day industries are experiencing an escalating trend in the applications of particulate and fiber reinforced polymer matrix composites. Some of these applications related to mechanical engineering experience surface interactions with the surroundings as well as with the pairing element. Such applications call for better understanding of the tribological behaviour of the material under study. Functional fillers are added to the thermoset matrix for improving its physical, mechanical and tribological properties. The modification of the mechanical, and tribological behavior of various polymers by the addition of filler materials has shown a great promise, and hence, it has been a subject of considerable interest. The filler materials include organic, inorganic, and metallic particulates in both macro- and nanolevels. Inclusion of solid lubricants such as graphite, molybdenum disulphide (MoS2), and polytetrafluoroethylene (PTFE) into polymers has proven effective in reducing the coefficient of friction but their influence on wear resistance is not distinctly clear . Wear rate was reduced with the addition of PTFE into polymers such as polyphenylene sulfide (PPS), polyvinylchloride (PVC), polyarylate (PA), polyoxymethylene (POM), and polyamide (PA) . Bolvari et al.  reported that the PTFE filled PPS reduced the wear rate of polymer remarkably. The role of PTFE filler in modifying the tribological behavior of fiber-reinforced composites has been studied
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