About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
Advances in Titanium Technology
|
| Presentation Title |
Defect-Driven Fatigue Behavior in LPBF Ti-6Al-4V: Insights from Fractographic Analysis |
| Author(s) |
Brett E. Ley, Austin Ngo, Oluwatumininu Adeeko, Anthony Rollett, Christian Gobert, Jack Beuth, John J Lewandowski |
| On-Site Speaker (Planned) |
Brett E. Ley |
| Abstract Scope |
In a prior study, LPBF Ti-6Al-4V four-point bending (4PB) and axial fatigue specimens were fabricated using both optimized and sub-optimal process parameters to investigate the influence of process-induced defects on fatigue performance. Specimens were tested to failure under cyclic loading, and fractography was conducted using scanning electron microscopy (SEM) to quantify defects on the fracture surfaces and identify the 'killer' defect(s) responsible for fatigue crack initiation. The size, location, and type of initiating defects were analyzed in relation to processing conditions and resulting fatigue life. A key observation was that specimens with nominally identical processing conditions and initiating defect characteristics could exhibit fatigue lives differing by more than an order of magnitude (>10×). This finding suggests that evaluating the microstructural 'neighborhood' surrounding the initiating defect, using techniques such as electron backscatter diffraction (EBSD), is a critical next step toward understanding and ultimately predicting fatigue behavior in as-built LPBF Ti-6Al-4V components. |