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Top1. Introduction
Fiber-reinforced polymer matrix composites have gained substantial attention as structural engineering materials in automotive, marine and aircraft industrial engineering applications. This is due to their outstanding mechanical properties, such as impact resistance, high durability, low coefficient of friction and thermal expansion, ability to provide higher load bearing capability in the directions of high loading, flexibility in design capabilities and relatively low density (Seyhan, 2008). One of the ways to enhance the mechanical properties of FRPs is to improve the properties of the epoxy matrix by incorporating second phase fillers into the resin. Polymeric nanocomposites, where at least one of the dimensions of the filler material is less than 100 nm, have shown significant improvements in mechanical properties (Thostenson, 2005; Hussain, 2006).
Reports of application of polymer and its composites in mechanical components such as gears, cams, wheels, impellers are cited in literature (Xue, 1997). The applications on these materials, to meet the present demands can be achieved by the introduction of fillers into these polymeric systems having fibrous reinforcement. The modification of the tribological behavior of polymers by the addition of filler materials has shown a great promise and so has lately been a subject of considerable interest. Nanometer SiC, micron SiC, and whisker SiC were used as fillers in polyetheretherketonc (PEEK) and the influence of these fillers on the friction and wear of the PEEK composites was studied (Chandramohan, 2007) and an effective reduction in the friction and wear has been achieved in the PEEK with Nanometer SiC as a filler. Tribological behaviour of glass epoxy polymer composites with SiC and Graphite particles as secondary fillers was studied using a pin on-disc wear rig under dry sliding conditions by Basavarajappa (2009), The results showed that the inclusion of SiC and Graphite as filler materials in glass epoxy composites will increase the wear resistance of the composite greatly.
However, the use of these filler based materials in actual service requires a careful cataloguing of the processing conditions employed and the attendant structure that follows. Experimental fracture characterization of composites was reported by many investigators. Arun (2010) investigated the mechanism of translaminar failure in hybrid polymer matrix composites is a typical combination of tensile and bending loads. The results have shown that the failure zone varies with the fabric volume, the initial crack size and the environment. It has been shown that dramatic improvements in mechanical properties can be achieved by incorporation of a few weight percentages (wt %) of filler materials (Ray, 2003; Alexandre, 2000). There are many research papers and several reviews on the mechanical properties of reinforced polymer nanocomposites (Tjong, 2006; Lau, 2006 & Xie 2005). Manjunatha (2010) worked on An anhydride-cured thermosetting epoxy polymer modified by incorporating 10 wt.% of well-dispersed silica nanoparticles and as a result it was found that The fatigue life of the GFRP composite was increased by about three to four times due to the silica nanoparticles.