锌/铝二元体系中溶解现象的分子动力学模拟

Molecular dynamic simulations for dissolution of Zn-Al binary system

摘要:

锌,铝和锌铝合金之间的溶解作用常见于钎焊,热浸镀和涂覆过程,如在制备Galfan、Galvalume镀层钢的过程中。工件如要通过预制的涂层来在获得良好的抗腐蚀性能,需使镀层材料中的锌和铝之间良好的润湿,本研究工作探究了在不同的Zn-Al二元合金体系中,影响锌和铝溶解程度的几个关键因素。我们研究动力学影响因素融入分子动力学模拟当中。原子尺度下的溶解润湿现象通过LAMMPS来模拟,在其中包含了Zn-5wt.%Al和Zn-6.8wt.%Al (Zn-15at.%Al)液态合金在Al(100),Al(110),Al(111)固体基板上润湿的模型。通过改变温度,提升Zn,Al之间的原子百分比,发现升高温度,提高液相中的Al含量可以促进Zn-Al组元的溶解。同时,本工作也通过分析表征溶解参数的变化,研究了温度,Al含量对溶解部分体积和扩散系数大小的影响。

Abstract:

Dissolution between Zinc, Aluminum and Zn-Al alloys are common in soldering, hot-dipping and coating, for example, when preparing galvalumed steel and Galfan-coated steel products. For manufacturers, they need to ensure that Zn wet Al well in order to endow the prepainted material with excellent corrosion resistance. This work aims at finding some key factors whichSdetermineSthe degree of dissolution in different Zn/Al binary systems. The consideration of investigating kinetic factors in dissolutive wetting process is brought into molecular dynamic (MD) simulation. Different atomic scale wetting process are performed with LAMMPS, simulation performances include Zn-5 wt.% Al, Zn-6.8 wt.% Al liquid models spreading on Al(100), Al(110), Al(111) solid substrates. By changing the temperature, elevating the percentage ratio of Zn, Al, it is found that Zn-Al binary dissolution can be pushed ahead by elevating temperature, or raising Al concentration in the liquid phase. Effects of temperature and atom percentages on dissolved volume and diffusion coefficient are also demonstrated by analyzing dissolutive parameters.