Effect of the time of mechanical activation of a Ti + 2B mixture on combustion of cylindrical samples and thin foils

The effect of the activation time of the Ti + 2B mixture on the burning rate of cylindrical samples and thin foils is studied. For cylindrical samples, combustion of samples activated in argon is compared with combustion of samples activated in air. The burning rates are almost identical in these two cases. It is demonstrated that the burning rate of cylindrical samples continuously increases with increasing activation time. The burning rate of thin foils remains almost unchanged as the activation time increases up to 4 min and then drastically increases and reaches a value twice greater than the burning rate of cylindrical samples. For the titanium and boron powders used in this study, the time needed to reach the maximum burning rate is 7 min in the case of activation in air and 5 min in the case of activation in argon; if the activation time is longer, then the product of combustion is formed. The features of combustion observed in this study can be explained from the viewpoint of convective-conductive model of combustion wave propagation.