Wear Properties of Reaction Sintered B4C Composites

B4C/CNTs and B4C/Ccomposites were prepared by reaction-sintering technique. The density and porosity of the samples were determined and three-points bending strengths of the composites were measured. Wear resistance tests were performed using a HT-500 pin-on-disc tribometer with the sample placed horizontally on a turning table. The morphology of the worn surfaces and fracture of the composites were examined by means of scanning electron microscopy so as to explore the wear mechanisms. The results indicate that B4C/CNTs composites show improved friction and wear properties as compared with B4C/C composites. It is found that CNTs in the specimens play important role in improving the wear properties of the composites. The wear mechanism of the B4C/CNTs composites is characterized by micro-cutting and plowing at ambient temperature, and sub-surface cracking and the resultant localized spalling on the worn surface at the temperatures higher than 500 degrees C.