Mathematical model for simultaneous growth of gas and solid phases in gas-eutectic reaction

Abstract

Simultaneous growth of solid and gas phases from gas supersaturated melt is the basis of a relatively new method for the production of ordered porosity materials. Such phase transformation is called gas-eutectic reaction. The structure obtained mainly depends on thermal and gas diffusion phenomena at solid/liquid interface. It is difficult to control this phase transformation but it is very important to the eventual structure. The development of a general mathematical model of the entire physical process will help for better understanding of the structure formation and will allow effective control to be provided. This paper presents a mathematical description of the complex physical phenomena during gas-eutectic transformation. Analyses for heat transfer, solidification kinetics and gas diffusion were coupled to describe the formation of the gas reinforced structure. The model was applied for simulation of structures after some special processing regimes. The structure sensitivity with respect to the different components of gas pressure is discussed.