High-temperature creep of carbon nanofiber-reinforced and graphene oxide-reinforced alumina composites sintered by spark plasma sintering

Alumina (AlO) ceramic composites reinforced with either graphene oxide (GO) or carbon nanofibers (CNFs) were prepared using Spark Plasma Sintering. The effects of GO and CNFs on the microstructure and in consequence on their mechanical properties were investigated. The microstructure of the sintered materials have been characterized quantitatively prior to and after the creep experiments in order to discover the deformation mechanism. Graphene-oxide reinforced alumina composites were found to be more creep resistant than carbon nanofibers-reinforced alumina ones or monolithic alumina with the same grain size distribution. In all the cases, grain boundary sliding was identified as the deformation mechanism.The authors acknowledge the financial support awarded by the Regional project of Excellence of ''Junta de Andalucía'' P12-FQM-1079 and the Spanish MINECO and FEDER funds through the projects MAT2015-71411-R and MAT2015-67586-C3-2-R