Influence of Mechanical Activation and Impurity Gas Release on the Macrokinetics of Combustion and the Product Structure in the Ti–C–B System for Pressed Compacts and Granulated Mixtures.

The influence of mechanical activation (MA) of the (100 – x)(Ti + C) + x(Ti + 2B) system on the characteristics of combustion of samples with different macrostructures—pressed compacts with a relative density of 0.53–0.6 and bulk density granules 0.6–1.6 mm in size—is studied. It is found that MA of powders leads to a gradual decrease in the combustion rate of pressed samples as the Ti + 2B content in the mixtures increases (a descending dependence), while an increase in the Ti + 2B content in compacts of nonactivated powders leads to an increase in the combustion rate (an ascending dependence). The obtained results contradict the theoretical ideas about the influence of MA on the combustion process, according to which the combustion rate should increase. One of the important factors influencing the change in the combustion rate is the release of impurity gases (IGs). For the first time, the influence of MA on the combustion patterns of granular mixtures is experimentally determined. It is found that the burning rates of granular mixtures are higher than those of powder mixtures for all the compositions studied. It is shown that granulated mixtures from an activated powder have a combustion rate that is on average 3 times higher than granules from a nonactivated powder, and the dependence of the combustion rate on the mass content of Ti + 2B has a local minimum, which is probably related to the peculiarities of the MA process. [ABSTRACT FROM AUTHOR]