Computer Simulation Of Microstructure Growth Based On The Temperature Field

In material research and industry applications, for a long time, it is difficult to guide to cast forming process for basal discipline theory knowledge and the quantify of classics theory, process design casting of projects can only build on experience basis. The model building-up has economized computer imitate material greatly having resolved the problem time and having shortened a production cycle, at the same time, it has also saved expenses and made material research and application jump out of repeated experiment of tradition method but have developed the method being principle-based.The article mainly in solidification process, two-dimensional macroscopic view temperature change process and growth of microcosmic organization process carry out a simulation on casting. The simulation to the macroscopic view temperature is used of the Fourier's conduct fundamental heat equation, adopt limited difference method to carry out scattering on the Fourier's conduct fundamental heat equation, having thought the three main border condition, and get net lattice partition on macroscopic temperature field, carriy out the temperature field simulation on the uniform distribution temperature and inhomogeneous distribution, at the same time, microstructure modeling has been carried out by using a CA (cellular automata) method coupled with macro heat transfer calculation. The stochastic nature of nucleation process as well as the deterministic of dendrite growth is considered to simulate the crystal growth. Continuous nucleation model is applied to describe heterogeneous nucleation in liquid metal. On the basis of the simplified grain shape, the physical model and mathematical model for the simplified dendrite shape were established. Dendrite tip growth kinetics is taken into account in the computing. In addition, the CA method is employed to describe the equiaxed grain growth in the under cooled melts and the node capturing during the further growth of a grain.The net lattice being in progress to the macroscopic temperature field being more detailed is divided, and adopt the method that D-value calculates to get the microcosmic simulation temperature scatters, the crystal latent heat to solidification process comes back to the macroscopic temperature field, build the connection between the macroscopic temperature field and microcosmic growth process thereby, carries out the entire simulation on metal casting solidification process, and compile and compose thetwo-dimensional simulation procedure having put up metal casting solidification process according to above-mentioned thought.