CDS&E/Collaborative Research: Fundamental Investigation of Zinc-Coating of Advanced High Strength Steels Directed by Multiscale Modeling and Experiments

新一代先进的高强度钢需要在衬底上涂上一层薄薄的锌，以提供腐蚀保护。因此，镀锌层是使钢材在更长的使用时间内保持结构完整性的关键部件。对涂层过程的预测和控制需要更好地了解锌与钢基材之间的界面反应，这是非常复杂的。该计算与数据科学与工程(CDS&amp；E)合作研究奖支持将尖端实验技术和多尺度计算机模拟相结合的基础研究，以研究涂层过程中形成的界面微结构。这项研究的结果将为改进先进的高强度钢板涂层提供指导方针，使生产出更轻、更安全的汽车，并最终有助于减少温室气体排放。该项目还提供了一个培养工科学生跨学科计算和实验技能的机会。锌-钢界面结构决定了先进高强度钢的成形、焊接和防腐能力的成败。由于复杂的冶金反应发生在小于100纳米的区域，因此缺乏关于镀锌和镀锌生产的镀锌钢的工艺-组织-性能关系的基本知识。研究小组将利用聚焦离子束制备样品，用于透射电子显微镜分析，以解析复杂、精细的界面微结构，并揭示界面实体的化学成分。这些数据将用于校准和验证从电子尺度到中尺度的跨长度尺度模型。将进行密度泛函理论计算，以确定氧化物和金属间化合物的结构和性质。所获得的数据将被用于基于改进的嵌入原子方法的多组分原子间势的计算。这些势将被用于大规模原子模拟，以确定氧化物和金属间化合物形成的能量学数据。实验和原子模拟数据将被提供给前所未有的多组分、多相场模型，以模拟内外氧化、缓蚀层和金属间化合物微观结构的形成和演化。实验和模型之间的迭代将为发现先进的高强度钢的新涂层工艺提供一种独特的方法。

New-generation advanced high strength steels need to be coated with a thin layer of zinc that provides corrosion protection to the substrate. Thus, zinc coating is a critical component that enables steels to maintain structural integrity for prolonged service times. Prediction and control of the coating process requires better understanding of interfacial reactions between zinc and steel substrate, which are very complex. This Computational and Data-Enabled Science and Engineering (CDS&E) collaborative research award supports fundamental research that combines cutting-edge experimental techniques and multi-scale computer simulations to study the interfacial microstructures that develop during coating. The outcomes of this research will provide guidelines for improved coating of advanced high strength steel sheets which enable production of lighter and safer vehicles, and ultimately contribute to reducing emissions of green-house gases. This project also provides an opportunity to educate engineering students with cross-discipline computational and experimental skills.The zinc-steel interfacial structures determine the success or failure of forming, welding, and corrosion protection capabilities of advanced high strength steels. There is a lack of fundamental knowledge regarding the process-microstructure-property relationships in zinc-coated steels produced by galvanizing and galvannealing, due to the fact that complex metallurgical reactions occur in a region less than 100 nanometers. The research team will utilize focused ion beam to prepare specimens for transmission electron microscopy analyses to resolve complicated, fine-scale interfacial microstructures and to reveal the chemistry of the interfacial entities. The data will be used to calibrate and validate cross-length scale models, spanning from the electronic to mesoscale. Density functional theory calculations will be performed to determine structures and properties of oxides and intermetallics. The obtained data will be used to develop multicomponent interatomic potentials based on the modified embedded-atom method. These potentials will be employed in large-scale atomistic simulations to determine energetics data for the formation of oxides and intermetallics. The experimental and atomistic modeling data will be fed to unprecedented multicomponent, multi-phase field models to simulate formation and evolution of microstructures of internal/external oxidation, inhibition layer, and intermetallics. The iterations between experiments and models will provide a unique approach to facilitate the discovery of new coating processes for advanced high strength steels.