Nature of the Increase in the Rate of Combustion of a Ti–C Mixture Diluted with an Inert Additive

Abstract

An original comparative study is performed of the combustion of granular and powder Ti–C and (Ti–C)+20%Ni mixtures with granules of different sizes, while varying titanium particle sizes in a range of 31–142 mm. It is found that the rate of combustion of the (Ti–C)+20%Ni powder mixture is 2–3 times higher than that of a Ti–C mixture, despite the lower temperature of combustion of the former. The results are interpreted in terms of the convective–conductive combustion model and attributed to the inhibitory effect of impurity gases that evolve while heating the component particles ahead of the combustion front. The rate of combustion of the granules’ material is calculated using those of granular mixtures with granule sizes of 0.6–1.7 mm. This rate can be thought of as the rate of combustion of a powder mixture in which the effect of impurity gases is neutralized. It is proposed that the ratio of the rates of combustion of the material inside the granules and the powder mixtures be used as a quantitative measure of the effect impurity gas evolution has on the combustion of powder mixtures.