A Mesoscopic Modelling Framework of Microstructure Evolution and its Application on Thermo-Mechanical Processes

Abstract

In present study a quantitative modelling framework based on phase-field method is developed to simulate the microstructure evolution during thermomechanical process, e. g. grain growth, recrystallization, solid phase transformations and their interactions. Two application cases of microstructure evolution are introduced. The first one is the dynamic recrystallization behavior during the hot deformation of stainless steel. The effect of thermo-mechanical parameters including strain, strain rate, and temperature on DRX have been investigated quantitatively. Moreover, the present simulation provided an explanation of the dependence of final recrystallized grain size on initial grain size when it is decreased to a critically small value. This modelling framework is also used to simulate the interaction between the dissolution of precipitates and grain coarsening of matrix in the nickel alloys. The simulation results show that the decreasing dissolution temperature of precipitate slow down the matrix coarsening kinetics obviously. This provides an quantitative tool to predict and control the local microstructure of nickel alloy disk. In summary, the mesoscopic modelling can be used to investigate more kinetic details of microstructure evolution and engineering optimization for thermo-mechanical process.