الفهرس 
CHAPTER ONE: INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The present work discusses the tribological performance of friction composites reinforced by natural fibers at continuous and starting – stopping tests aiming to provide specific relationship between the performances of the two tests. In the friction composites, asbestos is replaced by the tested natural fibers such as corn, palm and sugar bars. The proposed composites contain a mixture of phenolic resin (as matrix), metal powder (iron, copper, and aluminum), graphite, barium sulfate, and silica. Friction coefficient, wear, and temperature were accurately measured for the two tests (starting-stopping and continuous) to illustrate the effect of the different fibers ingredients and obtain a relationship between the performances of the two tests. Worn surface of the samples were examined and investigated by SEM scanning electron microscopy for discerning the coherence extent of different agriculture fibers with other components. The tribological properties of the new composite materials were compared with that of three commercial brake linings (brake lining A, brake lining B, and brake lining C), which are Egyptian, Chinese, and Turkish brake lining respectively.
Based on the observations in the present work, it was found that the tested natural fibers can replace asbestos in reinforcing the friction composites, where their friction and wear properties were much better than the commercial brake linings. It was observed that the relationship between the performance of the two tests depends on the fibers content inside the composites. The values of wear at continuous test are higher than that of starting – stopping test at same running distance due to the relatively higher velocity. The results showed that composites containing corn fibers and aluminum powder displayed the highest friction values with compared to the other tested composites due to the relatively strong adhesion of corn with aluminum. At starting – stopping test, the temperature increases with increasing contact pressure. The best fade resistance was displayed by composites containing high content of palm fibers and low content of iron powder.