论文标题
Al-MG合金中晶型隔离和晶界扩散的原子研究
Atomistic study of grain-boundary segregation and grain-boundary diffusion in Al-Mg alloys
论文作者
论文摘要
Mg晶界（GB）分离和GB扩散会影响Al-Mg合金的加工和性能。但是，AL中的MG GB扩散尚未通过实验测量或通过模拟预测。我们应用原子计算机模拟来预测MG GB分离的量和自由能，以及隔离对两种合金组件GB扩散的影响。在低温下，Mg原子隔离到具有高度各向异性形状的倾斜GB形成簇。 MG在Al GBS中的扩散比AL本身慢，并且与Al GB的自扩散相比，这两个组件都缓慢扩散。因此，Mg隔离显着降低了Al-Mg合金中GBS沿GB的质量转运率。降低的原子迁移率可能导致在升高温度下微观结构的稳定性提高。
Mg grain boundary (GB) segregation and GB diffusion can impact the processing and properties of Al-Mg alloys. Yet, Mg GB diffusion in Al has not been measured experimentally or predicted by simulations. We apply atomistic computer simulations to predict the amount and the free energy of Mg GB segregation, and the impact of segregation on GB diffusion of both alloy components. At low temperatures, Mg atoms segregated to a tilt GB form clusters with highly anisotropic shapes. Mg diffuses in Al GBs slower than Al itself, and both components diffuse slowly in comparison with Al GB self-diffusion. Thus, Mg segregation significantly reduces the rate of mass transport along GBs in Al-Mg alloys. The reduced atomic mobility can be responsible for the improved stability of the microstructure at elevated temperatures.
