Transformation of the Structure of ZnO–C Powders during Mechanical Activation and Spark Plasma Sintering

Abstract

The processes of grinding and transformation of the structure of the ZnO–C powder mixture at the mechanical activation by ball milling in an inert atmosphere have been investigated. The mechanical activation of the ZnO–C powder mixture is shown to lead to the formation of graphene oxide shells on the surface of crushed zinc oxide particles. The influence of the duration of activation of powder mixtures on the dynamics of their compaction during spark plasma sintering and structure of the ceramics obtained has been investigated. It is established that an increase in the activation duration to 100 h leads to a monotonic decrease in the density of sintered ceramics. The carbon shell formed during sintering at ZnO grain boundaries is shown to have the structure of reduced graphene oxide.