Cellular Automaton法模拟铝合金微观组织的形成

Microstructure Simulation of Aluminum Alloy on Cellular Automaton Method

采用Cellular Automaton微观模型,在给定冷却曲线的条件下,对铝合金板材凝固过程组织的形成进行了二维数值模拟。采用连续形核的方法处理液态金属的异质形核现象。用CA算法处理晶粒生长过程,考虑了枝晶尖端生长动力学和优先生长方向<100>晶向。通过模拟动态再现了凝固过程中晶粒的形核与生长。结果表明,在形核分布参数不变的情况下,随着冷却速度的增加,所得晶粒尺寸增大。

A two-dimensional Cellular Automaton model was adapted to simulate the microstructure of the aluminium-silicon alloy plate in solidification processes. A continuous nucleation model was used to deal with the heterogeneous nucleation of a liquid metal. A Gaussian distribution function was applied to describe the density of grains.In the CA model, the growth kinetics of dendrites and the preferential 〈100〉 crystallographic orientation were tallen into account. Based upon a two-dimensional Cellular Automaton technique, the visualization of grain formation can be achieved dynamically. Simulation results show that the obtained grain size increases with the increasing of the cooling speed.