Investigation of the laws of ignition of titanium powders

The study of the ignition characteristics of powders of the refractory transition metals is of scientific and practical importance. It is of interest to investigate the effect on the ignition process of such parameters as the composition of the gaseous oxidizer, the heat transfer conditions, the specimen dimensions, and the grade of metal powder. The article is devoted to the question of the ignition of transition metal powders, with titanium serving as an example. On the basis of the experimental data, several conclusions may be drawn. First, it was found that nitrogen has a chemical effect on the ignition of titanium powder in air only in the presence of an oxygen deficit. Second, a gas flow has a significant effect on the critical ignition temperature, reducing it at low and increasing it at high gas flow rates. It was further found that the titanium powder ignition process can develop in the autoignition and external ignition regimes. Generally good agreement was found between the theoretical and experimental values of the critical ignition temperature for titanium powder.