Experimental investigation of combustion of a gasless pelletized mixture of Ti + 0.5C in argon and nitrogen coflows

Effect of hydrogen content in titanium on the structure of the front and the specific features of the combustion of a Ti + 0.5C granular mixture in a cocurrent nitrogen flow

“…Then, the pressure in the tube drops below atmospheric pressure, which leads to the absorption of air from the atmosphere. Such a behavior of the pressure during the combustion process was observed in [5]. Processing video recordings of the combustion process, we found that, at the closed upper end of the tube, the burning velocity of the Ti + 0.5C granular composition is 4.7 mm/s.…”

“…The amount of gas in the titanium powder was measured by reductive melting under an inert gas atmosphere. A chemical analysis showed that the content of hydrogen in the initial titanium powder was 0.28 wt %, i.e., 3.5 times the amount of hydrogen in PTS-brand titanium, which was used by us in [5].…”

“…The mixtures were granulated as follows [5,7,8]: mixing a liquid and a solid phase, agglomeration of the powders, and subsequent rounding and strengthening of the cohesion between the particles by removing the liquid phase. The solid phase was a Ti + 0.5C powder mixture stirred for 30 min in a "drunken barrel" mixer.…”

“…In the present work, we studied the combustion of a granular mixture of titanium with carbon black in a quartz tube, with the charge bed being blown with nitrogen. In contrast to the previous studies [4,5], we used titanium with increased hydrogen content. Interest in studying the laws of the combustion of this system in a nitrogen flow is primarily motivated by the fact that the condensed reaction product formed can be titanium carbonitride TiC 0.5 N 0.5 , which, thanks to its advanced physicochemical properties, such as hardness, modulus of elasticity, and resistance to aggressive environments, is widely used for manufacturing tungsten-free hard alloys and protective coatings [6].…”

Hydrodynamic instability of counterflow filtration combustion: Mathematical modeling

“…However, the results of recent studies [2,3] suggest that the gas permeability of reactive media can be markedly improved by using granulated green mixtures and thus to carry out SHS reactions in conditions of forced infiltration at nearly atmospheric pressures.…”