Mg₂Ni燃焼合成の数学的モデル

抄録

A mathematical model of the combustion synthesis process is quite effective for its process design because the synthesis reaction occurs instantaneously in general. However, an experimentally-verified mathematical model of the combustion synthesis using practical properties and a reliable rate-equation has not been reported as yet. Very recently, a new energy-saving production process of Mg₂Ni through the combustion synthesis is attracting attention. The mathematical modeling of Mg₂Ni combustion synthesis has been proposed in this paper. First, the thermal diffusivity and the reaction rate of a sample to use in the mathematical model were measured by the method of laser flash and differential scanning calorimetry (DSC), respectively, and then correlated with the temperature and reaction degree. Secondy, an unsteady, two-dimensional mathematical model of heat transfer of a cylindrical sample was constructed, in which independently-measured properties and reaction rate equations were introduced. Finally, simulated data based on the mathematical model were compared with experimental data during the combustion synthesis of Mg₂Ni. As a result, their agreement was good enough for confirming the model. The feature of this model was to have a general rate equation with solid combustion and liquid-trigger combustion at a eutectic temperature, and to consider the influence of latent heat due to melt of a eutectic composition. Thus, the results also show the applicability of the mathematical model to other system of combustion synthesis.