Influence of Graphene Contents on Microstructure and High Temperature Oxidation Behavior of GNPs/Ti β21S Composites

GNPs/Ti β21S composites with various graphene additions were prepared by spark plasma sintering with Ti β21S powders and graphene powders as raw materials. The effects of graphene on the microstructure, phase composition and oxidation resistance at 1073 K and 1173 K were investigated. The results showed that all GNPs/Ti β21S composites possessed the porosity of not more than 0.2% and the average hardness higher than 470 HV and the oxidation resistance was influenced by the GNPs content. The GNPs/Ti β21S composites with various graphene additions oxidized at 1073 K and 1173 K were composed of TiO2, Ti, Nb2O3, Al2O3, MoO2, SiO2, and Ti2O3. At 1073 K, Ti β21S-0.8 wt.% GNPs composite exhibited the thinner oxidized layer and possessed better oxidation resistance than that of the other composites. At 1173 K, Ti β21S-0.2 wt.% GNPs composite possessed better oxidation resistance than that of the other composites.