Fatigue in Materials: Fundamentals, Multiscale Characterizations and Computational Modeling: Poster Session
Sponsored by: TMS Structural Materials Division, TMS Materials Processing and Manufacturing Division, TMS: Additive Manufacturing Committee, TMS: Advanced Characterization, Testing, and Simulation Committee, TMS: Computational Materials Science and Engineering Committee, TMS: Integrated Computational Materials Engineering Committee, TMS: Mechanical Behavior of Materials Committee
Program Organizers: Garrett Pataky, Clemson University; Ashley Spear, University of Utah; Antonios Kontsos, Drexel University; Brian Wisner, Ohio University; J.C. Stinville, University of Illinois Urbana-Champaign
Tuesday 5:30 PM
March 16, 2021
Room: RM 34
Location: TMS2021 Virtual
Micro-scale Characterization of Life-limiting Areas in Additive Manufactured Parts: Connor Varney1; Paul Rottmann1; 1University of Kentucky
Additive manufacturing (AM) has seen large interest in recent years for its ability to print complex parts that would be prohibitively expensive or unrealizable using conventional methods. Mechanical properties of AM alloys vary from those of conventional materials largely due to the complex processing conditions inherit to the additive process. Additionally, these complex parts generally have discontinuities (thin walls, sharp edges, holes, etc.) where the thermal history and, hence, properties differ from the bulk. Rather than relying on part-average properties and microstructure; micro-scale, site-specific characterization is required to generate robust predictive models for additive parts. This research focuses on using a micro-mechanical testing apparatus equipped with both monotonic and fatigue actuators coupled with real-time 2D DIC to explore the differences between areas near these discontinuities with those of the bulk of the part to gain a better understanding of how these discontinuities effect the performance of these parts.
The Effect of Corrosion Location Relative to Local Stresses on the Fatigue Life of Geometrically-complex, Galvanically Corroded AA7075-T6: Carly Cocke1; James Burns1; 1University of Virginia
Aluminum are used in aerospace structures and are commonly coupled together using stainless steel fasteners. These fastener sites are considered high stress locations due to the geometry of the through-hole acting as a stress concentrator and causing varying local stresses. The high stresses at the fastener sites preferentially initiate coating damage allowing for moisture ingress which can lead to the formation of a galvanic couple between the aluminum alloy and the stainless steel fastener. The corrosion damage and high local stresses from stress concentrators favorably initiate fatigue cracks thus severely reducing the total life of the component. This research is being performed in order to understand the importance of corrosion location and severity relative to a stress concentrator on the fatigue life. Critically, the findings of this work will inform the means by which coatings are evaluated and will serve as a controlled validation experiments for fracture mechanics modeling.