W2C-reinforced tungsten prepared using different precursors

Tungsten is considered to be the primary candidate material for high-heat-loaded structural parts in the DEMO demonstration fusion power plant. Its recrystallisation at high temperatures, which results in a loss of strength, can be suppressed by the incorporation of ceramic particles in the form of oxides or carbides. Here we propose the reinforcement of the W-matrix with W2C ceramic inclusions, which can be formed by a high-temperature reaction of the W-matrix with a carbide precursor. In this study the W2C particles were synthesised in-situ during vacuum sintering using three carbon sources: graphene, phenol-formaldehyde resin, and WC nanoparticles. Our results suggest that the WC nanoparticles are the most suitable carbon source for the formation of the W2C-W composite. The composite containing 24 wt% of W2C shows a denser structure and better mechanical properties compared to the pure tungsten. Additionally, ageing tests confirmed that the incorporation of W2C ceramic particles prevents the W-grain growth even at temperatures higher than 1200 degrees C.