Phase Field Formulations For Modeling The Evolution Of The Ostwald Ripening

The various methods in the simulation of microstructure evolution, the phase field method has a strong advantage. In these models, structure is defined by a set of fields, which are functions of space and time, Governing equations for the evolution of fields originate from the classical thermodynamics and dynamics theory of numerical calculation method, the field parameter within phases or grains is associated with an interface, which is no longer the difference between the interface between the mother and new faces, and also no longer need to locate interface in numerical value calculation. At present, the research on phase field method and the latest results mainly include the specific application, such as application examples of Solidification, solid-state phase transformation, grain growth, Ostwald ripening, interface-particle interaction and multiphase simulation are mentioned. The principle of these application mostly dues to Ostwald ripening, at the same time, the concentration of the application is different. So the Ostwald ripening of evolution plays a certain guiding role in material form.In this paper, Phase field method is used respectively to simulate the high and low volume fraction of Ostwald ripening evolution process, and then to simulate the two phase of Ostwald ripening process. Based on the simulation results with the existing experimental results, and analyzes the following innovation results and conclusion:1. Used the existing high volume fraction of Ostwald ripening process simulation, and compared with existing experimental results of semi-solid, reference distortion under different adaptation grid model of semi-solid processing, simulation results are in conformity with experimental results.2. Based on low volume fraction of Ostwald ripening of general, and is widely used in the new material, new model is established to simulate the low volume fraction of Ostwald ripening, with high volume fraction of Ostwald ripening same data analysis method, high and low volume fraction of Ostwald ripening of maturation phase in the way of nucleation are homogeneous precipitation aging, but the growth index of the dynamic coefficient of variation, high volume fraction of Ostwald ripening is greater than the low volume fraction of Ostwald ripening.3. Referenced high volume fraction of Ostwald model, to establish the binary Ostwald ripening model, concluded that the final simulated evolution form of dual curing phase by the size of initial concentration of liquid phase and the size of the average concentration.In the Ostwald ripening principle of formation of the material structure area of research, the conclusions of this paper play a guiding role, to some extent, and have the ability to control the structure of the material.