No abstract

International audienceThe hot-pressing kinetics of zirconium carbide were studied between 1700 and 2400° C in argon. The validity of different theoretical models due to Murray, Koval'chenko, Skorokhod, Scholz and Lersmacher was tested. For temperatures exceeding 2200° C, there is reasonably good agreement between kinetics and the whole set of models, but it has not been possible to classify them in order to draw conclusions on the sintering mechanism. The activation energy of ZrC hot-pressing was calculated, starting from the viscosity calculated by Murray's formula, as 41 kcal mol−1 (171.7 kJ mol−1)

A comparative investigation of the oxidation kinetics of ZrC0.963 and powders of the compositions ZrC0.79O0.10 and ZrC0.67O0.22 in the temp. range 400‐1000 °C under 100 torr O2 pressure shows that the oxidation becomes important above 400‐500 °C and that the oxidation resistance slightly decreases in the order ZrC0.963 > ZrC0.79O0.10 > ZrC0.67O0.22.