Combined effect of thermal and mechanical activation on the combustion and phase formation laws in the Cr-Si-C system

摘要

In this work combustion and phase formation laws for mechanically and thermally activated Cr-Si-C system were studied. For thermal stimulation in the combustion reaction Mg-(-C2F4-)_n high caloric mixture was used. It was shown that in the system under study, combustion takes place by two sequential stages. The first stage is interaction between Si and (C2F4-)_n or Mg with (C2F4-)_n (temperature can rise up to 1200°C), which are responsible for combustion front propagation. In the first stage, formation of small amount of CrSi2 takes place. The second stage is Si + C reaction which is responsible for high-temperature combustion. In the second stage, formation of CrSi2 completes. The influence of mechanical treatment on combustion laws for (Cr-Si) + (Si-C)+(Mg-(C2F4)_n) system was investigated. It was shown that mechanical activation (MA) is effective for systems where amount of chromium is high, while for systems where Si-C part is appreciable MA does not have any affect.