Effect of Graphite Addition on the Microstructure, Mechanical Properties and Oxidation Resistance of HfB2-SiC Composites Prepared by the SPS Method

In this study, HfB2-SiC-graphite composites were fabricated using spark plasma sintering at 1900 ℃ for 10 min. The effect of graphite content on the microstructure and mechanical properties was studied; also, oxidation resistance prepared investigated 1400 32 h. Weight changes thickness formed oxide layer measured. relative density, toughness strength SPSed increased with raising up 2.5 wt% then decraesed. On other hand, hardness decreased when added. Oxidation was, thus, improved following addition wt%, while ecessive quantity caused poor composites.