Indentation toughness of Al2O3-CNT nanocomposites

In the last few years new ceramic/carbon nanotube composites have been developed and a number of authors have reported improved mechanical and functional properties in the case of ceramic/CNT composites compared to the monolithic materials. according to the results reinforcing by CNTs in many cases improved the fracture toughness of Al2O3, however, this toughening is not evident, and some of the variations may purely arise from using different testing techniques. The improvement in fracture toughness is due to bridging of the crack surfaces by CNTs during the crack propagation by CNT pullout mechanism, which strongly depends on the interfacial bonding between CNTs and the matrix. The aim of the present work is to investigate the effect of addition of carbon nanotubes and carbon black on the indentation toughness of alumina-CNT and alumina-carbon black nanocomposites