NIST AM Benchmarks 2025: Predicting Fatigue Performance in Rotating Bending Tests of PBF-L Ti-6Al-4V
Please login to view abstract download link
AM Bench provides a continuing series of additive manufacturing (AM) benchmark measurements and challenge problems with the primary goal of enabling modelers to test their simulations against rigorous, highly controlled benchmark measurement data. In the latest cycle of these benchmark challenges, AM Bench 2025, one challenge focused on the prediction of fatigue properties in Ti-6Al-4V parts produced by laser powder bed fusion (PBF-L). Specimens underwent one of two heat treatment conditions. The first condition involved non-standard hot isostatic pressing (nicknamed 800HIP) treatment, and the second condition followed the same heat treatment, but in a vacuum furnace (nicknamed 800VAC). Approximately 50 rotating bending fatigue tests were performed in total. Using the 800HIP stress-cycles data for calibration purposes (S-N curves), modelers were asked to predict key fatigue properties of the 800VAC specimens. For example, these predictions included the median S-N curve and the crack-initiation locations of specific specimens. In addition to the S-N data of the 800HIP specimens, modelers were given the following calibration data (https://doi.org/10.18434/mds2-3734) for both heat treatment conditions (not exhaustive): solid chemistry, AM build parameters, heat treatment details, quasi-static tensile properties, 2D maps of grain size/morphology via scanning electron microscopy (SEM), 2D crystallographic texture via electron backscatter diffraction (EBSD), and pore size and spatial distributions vis X-ray computed tomography (XCT). In this talk, we delve deeper into the details of these measurements, as well as discuss the challenges we faced in designing a fatigue and fracture benchmark. Moreover, a first look will be taken at the predictions, in an anonymized fashion, with the goal of identifying trends in the submissions. We are also interested in sparking discussions within the community regarding the design of this challenge, including the solicitation of ideas that are relevant and impactful for future benchmarks.