ABSTRACT
The present work discusses the tribological performance of friction composites reinforced by corn and palm fibres 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 corn and palm leaf fibres. The proposed composites contain a mixture of phenolic resin (as matrix), metal powder (iron, copper, and aluminum), graphite, barium sulfate, and silica. Friction coefficient and wear were accurately measured for the two tests (starting-stopping and continuous) to illustrate the effect of the different fibres ingredients and to 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 fibres 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 linings respectively.
      
Based on the observations in the present work, it was found that the tested natural fibres 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 fibres content of the composites. The values of wear at continuous test are higher than that of starting – stopping test at the same running distance due to the relatively higher velocity. The results showed that composites containing corn fibres and aluminum powder displayed the highest friction values compared to the other tested composites due to the relatively strong adhesion of corn fibres with aluminum.