Effect of the Duration of the Mechanical Activation of Granulated Mixtures of 5Ti + 3Si on the Rate of Combustion Wave Propagation and the Elongation of Samples after Synthesis

Abstract

The effect the duration of the mechanical activation (MA) of preliminarily granulated mixtures of 5Ti + 3Si with titanium powder of different grades has on the dependences of combustion rates and changes in the length of samples after synthesis is studied. The dependences of the average particle size of a mixture on the duration of activation are established. It is shown that initial mixtures containing titanium of different grades have different combustion rates. It is concluded that mechanical activation leads to equalization of the combustion rates for powder mixtures at MA durations of more than 7 min and for preliminarily granulated mixtures at MA durations of 3 min. For powder mixtures, the combustion rate changes nonmonotonically as the duration of MA grows. For preliminarily granulated mixtures, it first slows and then increases monotonically. An explanation of the observed dependences is proposed. It is shown that in contrast to powder mixtures, there is a sudden increase in the relative length of samples during combustion after the MA of granulated mixtures with a duration of 1 min. This is because with granular MA mixtures, the main evolution of gas from the decomposition of bonds occurs behind the combustion front, in contrast to mixtures without MA. It is shown that the dependences of the relative length of the samples after burning on the duration of MA are close to those of mixtures with both grades of titanium.