Electrothermal explosion under pressure: Ti–C blends in porous electroconducting envelope

International Journal of Self-Propagating High-Temperature Synthesis - Tập 25 - Trang 39-42 - 2016
V. A. Shcherbakov1, A. N. Gryadunov1, V. T. Telepa1, A. V. Shcherbakov1
1Institute of Structural Macrokinetics and Materials Science (ISMAN), Russian Academy of Sciences, Chernogolovka, Moscow, Russia

Tóm tắt

Influence of applied pressure P and intensity of Joule heating on electrothermal explosion (ETE) in Ti–C blends placed in a porous electroconducting envelope was studied by using a home-made experimental setup. A distinctive feature of this system is non-linear warm-up prior to initiation of ETE. A non-linear temperature growth during pre-explosion warm-up was associated with gradual decrease in the electrical resistance of the sample caused by intensification of mass transfer processes leading to an increase in current density and hence in heating rate. During the warm-up period, the extent of conversion was found to attain a value of about 15%. In classical theory of gasless combustion, chemical reaction within the warm-up zone is neglected and it is postulated that combustion reaction gets started at temperatures close to the melting point of a low-melting reagent. Our results cast some doubt on the validity of the above adoptions and thus shed new light on the mechanism of SHS reactions in heterogeneous systems.

Tài liệu tham khảo

Shteinberg, A.S., Thermal analysis of high-temperature fast reactions in energetic materials, J. Therm. Anal. Calorim., 2011, vol. 106, no. 1, pp. 39–46; DOI: 10.1007/s10973-010-1271-1.

Thiers, L., Mukasyan, A., and Varma, A., Thermal explosion in Ni–Al system: Influence of reaction medium microstructure, Combust. Flame, 2002, vol. 131, no. 1, pp. 198–209.

Vadchenko, S.G., Boyarchenko, O.D., Shkodich, N.F., and Rogachev, A.S., Thermal explosion in various Ni–Al systems: Effect of mechanical activation, Int. J. SelfProp. High-Temp. Synth, 2013, vol. 22, no. 1, pp. 60–64.

Shteinberg, A.S., Lin, Y.C., Son, F., and Mukasyan, A.S., Kinetics of high temperature reaction in the Ni–Al System: Influence of mechanical activation, J. Phys. Chem., Ser. A, 2010, vol. 114, no. 20, pp. 6111–6116.

Shteinberg, A.S. and Knyazik, V.A., Macrokinetics of high-temperature heterogeneous reactions: SHS aspects, Pure Appl. Chem., 1992, vol. 64, no. 7, pp. 965–976.

Knyazik, V.A. and Shteinberg, A.S., The laws of thermal explosion in the systems with additional nonchemical source of heat, Dokl. Akad. Nauk SSSR, 1993, vol. 328, no. 5, pp. 580–584.

Shteinberg, A.S., Knyazik, V.A., and Gorovenko, V.I., Thermal analysis of high-speed high-temperature reactions of refractory carbide synthesis, J. Therm. Anal., 1993, vol. 40, no. 1, pp. 363–371.

Popov, K.V., Knyazik, V.A., and Shteinberg, A.S., High-temperature reaction of Ti with B by the method of electrothermal explosion, Combust. Explos. Shock Waves, 1993, vol. 29, no. 1, pp. 77–81.

Knyazik, V.A. and Shteinberg, A.S., High-temperature reaction in the Ta–C system under electrothermal explosion conditions, J. Mater. Synth. Process., 1993, vol. 1, no. 2, pp. 85–92.

Knyazik, V.A., Merzhanov, A.G., and Shteinberg, A.S., On combustion mechanism in the Ti–C system, Dokl. Akad. Nauk SSSR, 1988, vol. 301, no. 4, pp. 899–902.

Shcherbakov, V.A., Gryadunov, A.N., Telepa V.T., and Shcherbakov, A.V., Electrothermal explosion in Ti–C mixtures under pressure, Int. J. Self-Prop. High-Temp. Synth., 2014, vol. 23, no. 2, pp. 122–124.

Bostandzhiyan, S.A., Gordopolova, I.S., Shcherbakov, A.V., and Shcherbakov, V.A., Electrothermal explosion in cylindrical Ti–C charges in a TiC shell: a mathematical model, Int. J. Self-Prop. High-Temp. Synth., 2012, vol. 21, no. 3, pp. 183–188.

Bostandzhiyan, S.A., Gordopolova, I.S., and Shcherbakov, V.A., Modeling of electrothermal explosion in gasless systems placed into an electroconducting medium, Combust. Explos. Shock Waves, 2013, vol. 49, no. 6, pp. 668–675; DOI: 10.1134/S0010508213060051.

Grigor’ev, E.G. and Kalin, B.A., Elektroimpul’snaya telhnologiya formirovaniya materialov iz poroshkov (Electropulse Processes for Preparation of Materials from Powders), Moscow: Izd. MIFI, 2008, pp. 23–33.

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International Journal of Self-Propagating High-Temperature Synthesis

Tập 25

39-42

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