The trustworthiness of AM metallic materials is not well characterized. Therefore, fatigue models that consider the unique microstructure and porosity inherent to AM parts are needed. Herein, a microstructure-based fatigue model is calibrated for use in predicting fatigue life of additively manufactured (AM) Ti-6Al-4V. Various Ti-6Al-4V samples, with variations in porosity, were fabricated using Laser Engineered Net Shaping (LENS), a Direct Laser Deposition method. LENS samples in the as-built and heat treated conditions, together with wrought Ti-6Al-4V samples, underwent fatigue testing, as well as microstructure and fractographic inspection. The collected microstructure/defect statistics were used for calibrating a microstructure-sensitive fatigue model. LENS Ti-6Al-4V sample fatigue lives were found to be consistently less than those of the wrought Ti-6Al-4V samples, due to the presence of pores/defects within the LENS material. Results further indicate that fatigue life predictions from the employed model were in close agreement with experimental results.
| Identifer | oai:union.ndltd.org:MSSTATE/oai:scholarsjunction.msstate.edu:td-5918 |
| Date | 09 December 2016 |
| Creators | Torries, Brian Anthony |
| Publisher | Scholars Junction |
| Source Sets | Mississippi State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Theses and Dissertations |
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