On the Nature of the Multidirectional Change in Combustion Velocity of Ti-based Powder Mixtures When Diluted with Inert Additives

Abstract

Macrokinetic parameters of combustion of powder and granular mixtures were studied upon dilution of Ti + C with various metal powders. The combustion velocities of powder mixtures (Ti + C) + 20% Me (Me = Ni, Cu) turned out to be higher than those of Ti + C blend, despite the lower temperature of combustion. When diluting Ti + C mixture with Ti or TiC powders, there was no such a contradiction. The convective-conductive model of combustion explains obtained data by a strong influence of impurity gas release from titanium particles ahead the combustion front. The time of combustion transfer between the granules, the combustion velocity inside the granules, and the quantitative assessment of the retarding effect of impurity gases in powder mixtures were determined. When comparing the combustion parameters of granular Ti + C mixtures diluted with various metal powders and titanium carbide, the efficiency of the combustion transfer between the granules in the presence of hot Ni melt was explained. In addition, the impurity gas reabsorption by titanium carbide was confirmed.