About this Abstract |
Meeting |
MS&T21: Materials Science & Technology
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Symposium
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Additive Manufacturing: Processing, Microstructure and Material Properties of Titanium-based Materials
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Presentation Title |
Effects of Process Parameters on Fatigue Behavior and Defect Characteristics in LPBF Ti-6Al-4V |
Author(s) |
Austin Q. Ngo, David Scannapieco, Hunter Taylor, Ryan Wicker, Joseph Pauza, Anthony Rollett, John Lewandowski |
On-Site Speaker (Planned) |
Austin Q. Ngo |
Abstract Scope |
Four-point bending fatigue testing was conducted on machined and polished LPBF Ti-6Al-4V mechanical testing specimens built with varying process parameters. Optimized and sub-optimal process parameter sets were selected to fabricate baseline builds and defect-induced builds, respectively. S-N fatigue data was generated for each process parameter set, and specimen fracture surfaces were imaged using OM and SEM. Fractographic analyses consisted of quantifying all defects on the fracture surface, identifying ‘killer’ defects responsible for fatigue failure, and estimating fracture toughness from the crack length at catastrophe. Fracture surface height profiles were generated via laser scanning and compared to visual analyses of crack progression. Different types of process defects (i.e. lack of fusion, keyhole) were found to be more prevalent based on particular process parameter sets, which further influenced S-N curves. The effects of process parameters on defects and resulting S-N fatigue will be discussed in the context of a Kitagawa-Murakami-type approach. |