In this STTR effort, TDA will focus on developing a unified multi-physics and statistical-based framework to optimize electroplating parameters, and to predict the influence of defect, residual stress, and environment on fatigue strength of high strength steel (HSS) aerospace component. The proposed approach accounts for both hydrogen embrittlement and residual stress effects on fatigue performance. The key investigations of the proposed approach are: 1) development of multi-physics and multi-scale electroplating simulation module to characterize electrochemical and mechanical processes for Zn-Ni Electroplating; 2) development of multi-objective optimization algorithms to determine the optimum settings of the electroplating process that result in the optimum Zn-Ni coating; 3) critical sets of experiments to validate our electroplating simulation module, and identify the types and causes of plating defects. The framework will enable engineers to reliably predict electrochemical/mechanical behavior and suggest design parameters to optimize electroplating process for aerospace component instead of going through several experimental trials.
Benefit: Our work effort brings the philosophies of integrated computational materials engineering into the field of electroplating science and engineering. Our investigations on clarifying the mechanisms by which the integrity of the coating/surface interface at various conditions is degraded and how the fatigue performance is affected provides significant pay-off to different stakeholders. This work effort lays the ground work groundwork for using science-based versus empirical material designs in electroplating industries. TDAs envisioned product will provide a multi-scale and multi-physics models and optimization framework for electroplating process. This framework enables the user to predict the fatigue life of Zn-Ni coated HSS and corrosion resistance as a function of design, electroplating process under service loading and environment. Our framework takes the users specific part geometry, process and environmental conditions, mechanical loading and functional requirements, and provides suggested design and process parameters to maximize fatigue life and electrochemical/mechanical performances at part level. This tool will be unique for developing a quick rational initial design space to target product performance. Our tool will help in speedy prediction and optimization of electroplating process for aerospace component instead of going through several trials. Besides the Navy specific application in aerospace system, the developed modeling tool can find application in the automotive industry, the ship industry, the nuclear and energy industry, the oil and gas industry. The framework suggested herein will be able to powerfully complement and possibly reduce the extent of accelerated laboratory testing that is required.
Keywords: Residual Stress, Residual Stress, electroplating, molecular dynamics simulations, Zn-Ni Coating, Multi-objective optimization, Fatigue Strength, Multi-physics Phase-Field Modeling, hydrogen embrittlement
