| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Additive Manufacturing Fatigue and Fracture IV: Toward Confident Use in Critical Applications
|
| Presentation Title |
The Role of Surface Condition in High-cycle Fatigue Behavior in Laser Powder Bed Fusion Materials |
| Author(s) |
David B. Witkin, Thomas Albright, Dhruv Patel, Tait McLouth, Glenn Bean |
| On-Site Speaker (Planned) |
David B. Witkin |
| Abstract Scope |
Surface features are the primary control on fatigue crack initiation in materials made by additive manufacturing that have been hot isostatically pressed. Surface roughness alone, however, is not adequate to capture the types of features where fatigue cracks are initiated. Using Inconel 718 made by laser powder-bed fusion as a model alloy, comparison of S-N curves over a range of specimen types, specimen geometries, stress ratios, and surface conditions show that materials with similar post-print thermal histories have similar S-N behavior. Use of contour scans on round specimens tested with as-produced surfaces strongly biases the azimuthal fatigue crack initiation location with respect to the printer’s axial frame of reference. The largest differences in fatigue properties due to differences in as-produced surfaces are expected to manifest themselves only when the number of cycles to failure is one million or greater. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |