Gas-Free Combustion of Ti-C-Al Reaction Mixtures in a Thermal Explosion
A. V. Baranovskii, G. A. Pribytkov, V. V. Korzhova
Institute of Strength Physics and Materials Science, Siberian Branch, Russian Academy of Sciences, Tomsk, Russia
Keywords: titanium, carbon, aluminum, thermal explosion, titanium carbide, titanium trialuminide, mechanical activation
Abstract
Phase composition of thermal explosion products in compacts made of Ti-C-Al powder mixtures with an equiatomic ratio of titanium and carbon (soot) and with an aluminum content of 10 ÷ 40 % (wt.) is studied. The compacts are heated at a rate of 40 ± 5 °C /min in an argon atmosphere. Self-ignition temperature of all compositions was close to the melting point of aluminum (660 °C). Peak temperatures and the maximum rate at which temperature elevation becomes higher as the aluminum powder content in the mixtures increases. Synthesis products contain titanium carbide and Al3Ti titanium trialuminide, whose ratio depends on the aluminum content in the mixture. Pretreatment of reaction mixtures in a planetary mill flattens aluminum particles, thereby preventing the formation of a melt. The spreading of a melt over the titanium surface with subsequent reaction diffusion and the formation of Al3Ti increases the temperature in compacts made of nonactivated mixtures.
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