Combustion features in the Mo–Si–B system Part 2. The effect of mechanical activation

Abstract

The work is devoted to the investigation of the effect of mechanical activation (MA) on the kinetics and mechanism of reaction mixture combustion in the Mo–Si–B ternary system as well as ceramic material production by the SHS method. Elemental molybdenum, silicon, and boron powders were used as initial components. The mechanical activation was carried out in a planetary mill. MA regimes with maximum heat release amount and rate were determined. As a result, the MA increases heat release rate and the reactive capability of the mixture at the cost of reagent size reduction, re- duction of coherent-scattering regions, and increase in the density of structural defects and dislocations. In contrast to inactivated mixtures, the ini- tial temperature dependence of combustion temperature and rate are linear for MA mixtures. The quantitative estimate of MA contribution into the effective activation energy ( E eff ) of the combustion process is carried out.