电磁搅拌作用下铝合金凝固组织的数值模拟

Numerical Simulation of Solidification Microstructure in Aluminum Alloy under Electromagnetic Stirring

以Al-5Cu合金作为研究对象,建立了形核生长的数学模型。采用数值模拟与试验相结合的方法,分析了电磁搅拌、搅拌电流及搅拌频率对合金凝固组织的影响。结果表明,不施加电磁搅拌时,熔体温度梯度较大,获得的凝固组织粗大;施加电磁搅拌时,熔体温度梯度较小,获得的凝固组织均匀细小。在一定范围内,搅拌电流越大,形成的凝固组织越细小;搅拌频率越大,形成的凝固组织越粗大。

Mathematical model of nuclear growth of Al-5Cu alloy was established. Effects of electromag- netic stirring, stirring current and stirring frequency on the solidification structure of the alloy were ana- lyzed. The results reveal that, without electromagnetic stirring, the solidification microstructure of Al- 5Cu alloy exhibits coarse as a result of the high temperature gradient of melt, while with electromagnetic stirring, the solidification microstructure is refined due to low temperature gradient. In addition, to some certain, with the stirring current increase, solidification microstructure of the Al-5Cu alloy is re- fined, while with increasing in the stirring frequency, the solidification rnicrostructure of the Al-5Cu al- loy is coarened.