Corrosion Resistant Naval Alloys: Innovative Multi-Scale Computational Modeling and Simulation Tools

Advanced computational tools capable of predicting the effects of fatigue corrosion on new alloys are needed to design the aircraft fleet of the future. The corrosion process is complex involving a combination of factors including material chemistry, processing history, microstructure, and operational environment. During the Phase I, VEXTEC demonstrated physics based corrosion pit nucleation model integrated within a probabilistic fatigue model to predict the corrosion influence on fatigue. VEXTEC simulated an aircraft under-wing panel made of Al 7075 under realistic mission loads and showed that corrosion reduced the fatigue life by 33%. The Phase II will fully develop this capability into a prototype design tool. The corrosion model will be extended to include pit formation, annodic dissolution and embrittlement for both Al 7075 and Al7050 materials. Under Phase IIB the capability will be further extended to predict Al2024 behavior. It will be shown that a prototype software can be used to predict design influence factors on a realistic Navy component.