Spark plasma sintering of ZrCx-ZrB2 composites

The study of spark plasma sintering of ZrCx and of different ZrCx-ZrB2 composites has been carried out in taking into account the effect of some parameters as the pressure, the temperature and the isothermal holding time. The transmission electron microscopy analysis of these composites show the formation of a fluid phase and the complete re-arrangement of the free carbon under the form of graphite during the thermal cycle. Moreover, the observation of the dislocations has shown the preferential plastic shakedown of the deformation by the ZrB2 crystals. At last, the oxidation resistance under air of the composites increases with the ZrB2 amount. (O.M.)