Mathematical Modeling of Chemical Conversionin Thin-Layer模料模具材料工程毕业设计外文翻译.doc

Mathematical Modeling of Chemical Conversionin Thin-Layer Exothermic Mixtures underPeriodic Electric-Spark Discharges B. S. Seplyarskii,1 T. P. Ivleva, and E. A. Levashov2 Translated from Fizika Goreniya i Vzryva, Vol. 40, No. 3, pp. 59–68, May–June, 2004. Original article submitted April 23, 2003. Abstract: The dynamics of coating production using a reaction mixture with thermoreactive electric-spark strengthening is studied numerically. It is shown that the main parameter that determines the thermal regime of coating is the initial thickness of the mixture layer. The parameter ranges for the process in a combustion regime and in a quasivolume conversion regime are determined. The effect of discharge frequency and the thermal characteristics of the reaction mixture and the substrate being strengthened on coating time is investigated. It is established that for a particular reaction mixture, the characteristic conversion temperature can be controlled by varying the electric discharge power and, hence, the heat flux at the active stage of the process,and for coating formation at this characteristic temperature, it is necessary that the thickness of the active layer be lower than a certain critical value. Key words: mathematical modeling, chemical conversion, mixtures, action, charge. One of the widely used methods for the surface strengthening of dies, rolls, and cutting tools is electric-spark alloying [1]. To apply functional coatings,Podlesov et al. [2, 3] used electrodes produced by self-propagating high-temperature synthesis (SHS) [4]. In this case, for each particular problem of surface strengthening, it was necessary to develop a technology to produce electrodes of the required composition. Levashov et al. [5–7] were the first to propose to combine the processes of electric-spark alloying and SHS in the interelectrode gap. This method was called thermoreactive electric-spark strengthening (RESS). The idea of the TRESS method is that an electric discharg