Polymer matrix composites are an important category of engineering materials that need to improve their properties according to the intended application. The development of self-lubricant composites is one of the latest activities in the field of tribology of composites, which prevents energy loss and increases performance efficiency. Improving the wear behavior of epoxy resin as one of the widely used industrial polymers through the production of self-lubricant composites is the main focus of this research. The production of two types of composites containing mat from solid microfibers and microfibers with core-shell structure is the chosen method to achieve self-lubricant properties. By using coaxial electrospinning process, fibers with oil core and shell made of polystyrene were produced along with 2% by weight of graphite nanoparticles. The placement of such fibers near the surface of the composite causes the partial destruction of the fiber shell against wear and the introduction of oil to the contact area. Graphite nanoparticles are present in the shell of fibers with the aim of creating solid lubrication properties. Therefore, such a composite will have solid and liquid lubrication properties at the same time. Solid microfibers made of polystyrene and graphite nanoparticles were also made by electrospinning process. Considering that wear is a surface phenomenon, the produced microfibers were placed on the surface of the samples and carbon fibers with the aim of improving the mechanical properties in the depth of the composites. After the production of the two types of microfibers, the composite manufacturing process was carried out by vacuum infusion process. The pin on disk wear test was performed to experimentally eva‎luate tribological behavior of three pure epoxy materials, the composite containing solid fibers and the composite containing fibers with an oil core. To compare the behavior of these three types of materials, wear tests were performed at to forces of 15N and 30N, two speeds of 0.1m/s and 0.2m/s and a distance of 500m. To ensure the accuracy and reproducibility of the results, each test was repeated three times. According to the obtained results, the friction coefficient and wear rate of the composite containing fibers with oil core is significantly lower than other samples. The average coefficient of friction of composite containing solid fibers is lower than of pure epoxy. While the wear rate of these two materials is not much different. For example, the average coefficient of friction at a force of 15N and a speed of 0.2m/s for pure epoxy, composite containing solid fibers and composite containing fibers with oil core was obtained as 0.26, 0.17 and 0.07, respectively. The average wear rate for these materials in the same test conditions was equal to 2.98×10-4mm3/N.m, 3.09×10-4mm3/N.m and 1.48×10-4mm3/N.m. therefore, the presence of oil in the core of the fibers and acting as a liquid lubricant has improved the tribological behavior of the sample, which is an expected result. The presence of graphite nanoparticles in the fiber structure has also reduced the friction coefficient. The proper performance of the composite containing fibers with oil core in loading and light sliding speed is a promising result for continuing this research and using the same idea to make wear resistant polymer industrial parts.

صالح اكبرزاده , رضا جعفري ندوشن

حسين فشندي , عليرضا علافچيان

مهدي جوان بخت , محمد سيلاني