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

Missouri University Of Science And Technology, Rolla MO

Investigators

Abstract

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.