One of the problems with designing fusion power plant is the choice of materials that will withstand extreme conditions in proximity of plasma. Suitable materials for this application could be tungsten composites. Pure tungsten starts to recrystallize at high temperatures, where grain growth occurs, and that leads to a deterioration of the mechanical properties of the material. A potential solution is a tungsten composite with ditungsten carbide (W2C) particles that limit the growth of tungsten grains and thus inhibit recrystallization.
In my thesis I prepared four mixtures of tungsten and tungsten carbide (WC) powders of different concentrations. The samples were densified using the SPS technique. Microstructure was analyzed using SEM and the phase composition of the samples was determined using XRD. Hardness of the prepared samples was compared with the hardness of the same samples that were aged. The hardness of composites with higher W2C content is higher. The hardness of the specimens before and after aging at all temperatures is the same, so we can conclude that recrystallization in our samples did not occur under the selected conditions during aging.
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