About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
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Symposium
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Fatigue in Materials: Fundamentals, Multiscale Characterizations and Computational Modeling
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Presentation Title |
Understanding the Connections Between Microstructural Features and Fatigue Crack Initiation and Propagation Properties in Medical Formulations of Ultra-high-molecular-weight-polyethylene (UHMWPE) |
Author(s) |
Bethany Smith, Qin Yu, Lisa Pruitt, Robert Ritchie, Samantha Kwan, Alex Sangster, Jon Ell |
On-Site Speaker (Planned) |
Bethany Smith |
Abstract Scope |
Though UHMWPE has been used in joint replacements since the 1960’s, newer processing techniques and chemical formulations are introduced regularly to improve clinical performance, creating new research opportunities in an otherwise well-studied material. This research investigates how crystallinity, inter-lamellar spacing, lamellar thickness, and amount of crosslinking affect both the fatigue crack initiation and propagation properties in multiple medical formulations of UHMWPE. To accomplish this, differential scanning calorimetry (DSC) and small-angle x-ray scattering (SAXS) techniques were implemented to characterize the microstructures of five medically-relevant UHMWPE formulations. Afterwards, CT specimens adhering to ASTM E647 were used to create da/dN vs.ΔK curves under both ΔK increasing and decreasing conditions for those same formulations. Using Paris Law constants C and m and threshold ΔK's as comparison metrics, preliminary results indicate that microstructural features that increase ΔK threshold tend to also have a negative effect on propagation properties, likely due to crosslinking impeding plastic deformation. |
Proceedings Inclusion? |
Planned: |
Keywords |
Polymers, Mechanical Properties, Biomaterials |