合金沉淀过程的微观相场法计算机模拟

Computer Simulation of Alloy Precipitation Using Microscopic Phase Field Method

讨论了连续体相场动力学与微观相场动力学理论在描述合金相变方面各自的特点。基于微观相场动力学理论建立的微扩散方程,以原子占位几率和序参数描述合金沉淀过程的原子簇聚和有序化。该模型将三维问题进行二维投影,在倒易空间求解,直观给出原子演化图像,并可描述形核、长大、和粗化在内的全过程。微扩散模型已成功用于二元及三元合金沉淀机制及微观组织的模拟。

This paper discusses the characteristics of continuous and microscopic phase field dynamics theory on describing phase transformation of alloys. The microscopic diffusion equation is based on microscopic phase field theory, which describes the atom clustering and ordering by ordering parameter and the probabilities of finding an atom at a given lattice. The model using 2-D projections for a 3-D system solves the equation on reciprocal space and gives the atomic picture directly. Besides these, it can describe nucleation, growth and coarsening. Microscopic diffusion model has been used successfully on ordering and microstructure simulation of binary and ternary alloy precipitation mechanism and microstructure.