This document provides details on the experiment and associated measurement files available for download in the dataset ?In Situ Thermography During Laser Powder Bed Fusion of a Nickel Superalloy 625 Artifact with Various Overhangs and Supports.? The measurements were acquired during the fabrication of a small nickel superalloy 625 (IN625) artifact using a commercial laser powder bed fusion (LPBF) system. The artifact consists of two half-arch features with increasing degrees of overhangs, from 5° to 85°, in increments of 10°. The artifact geometry and process are controlled to ensure consistent processing along the overhang geometry, thus enabling the effect due to overhang geometry and support structures to be isolated from effects due to inter-layer scan-strategy variations that are typical in commercial LPBF processes. The measurements include high-speed thermography of each layer, from which radiant temperature, cooling rate, and melt pool length are calculated. The objective of this experiment and data dissemination is twofold. First, to provide data for the modeling community for model validation to ensure that their models are accurately accounting for the effect of overhang geometries and support structures in thermal models. The second objective is to provide fundamental insight into these effects for researchers and process designers.

This dataset contains thermographic measurements acquired during single and multiple track scans on bare substrates and on single layers of powder. The substrates and powder are nickel alloy 625 and the experiments are performed inside a commercial laser powder bed fusion machine. There are four experiment cases: 1) a single scan track on a bare substrate, 2) a single scan track on a single hand-spread layer of powder, 3) multiple (39) scan tracks covering an area on a bare substrate, and 4) multiple (39) scan tracks solidifying a single hand-spread layer of powder. Thermographic measurements are performed using a camera system sensitive to wavelengths between 1350 nm and 1600 nm. The camera acquires frames with an integration time of 0.04 ms and a frame rate of 1800 frames per s. The camera signal and radiant temperature values based on a black body calibration are provided. True temperature is not provided because emissivity of the surfaces is unknown. This data was used to measure melt pool length and cooling rate based on radiant temperature as part of the work in: Heigel, J. C. & Lane, B. (2017). "The effect of powder on cooling rate and melt pool length measurements using in situ thermographic techniques." In Proceedings of the 2017 Annual International SFF Symposium (https://www.nist.gov/publications/effect-powder-cooling-rate-and-melt-pool-length-measurements-using-situ-thermographic)

These measurements were performed as part of the 2018 Additive Manufacturing Benchmark Test Series (AM-Bench), specifically supporting the melt pool geometry challenge (CHAL-AMB2018-02-MP) and cooling rate challenge (CHAL-AMB2018-02-CR). This dataset and the associated experiments are part of a continuing series of controlled benchmark tests, in conjunction with a conference series, with two initial goals, 1) to allow modelers of Additive Manufacturing processes to test their simulations against rigorous, highly controlled additive manufacturing benchmark test data, and 2) to encourage additive manufacturing practitioners to develop novel mitigation strategies for challenging build scenarios. More information regarding the AMBench 2018 study can be found at www.nist.gov/ambench. Multiple laser scan tracks were performed on bare nickel-based superalloy IN625 substrates using three different combinations of laser power and scan speed. A high-speed infrared camera was used to measure the infrared emissions during each scan track, allowing measurement of the melt pool length and cooling rate of the solidified material. Details related to this dataset are provided in the associated NIST Journal of Research article (in press). The associated publication with experiment details and ex-situ characterization is Lane et. al. 2020 (https://doi.org/10.1007/s40192-020-00169-1).For dataset description article; refer to https://doi.org/10.6028/NIST.AMS.100-53

This challenge is a follow-on from AMB2022-01 laser powder bed fusion (PBF-LB) alloy Inconel 718 in the as-built condition (no heat treatment). Eight continuum-but-miniature tensile specimens were excised from the same size legs (2.5 mm width) of one original AMB2022-01 specimen (AMB2022-718-AMMT-B7-P4). Excised tensile specimens were quasi-static uniaxially tensile tested according to ASTM E8 (strain rate 1*10-3 sec-1, 3 mm gauge length custom contact extensometer). Calibration data given includes all processing and microstructure data from AMB2022-01 (https://www.nist.gov/ambench/am-bench-2022-challenge-problems-and-measurement-results), including 3D serial sectioning electron backscatter diffraction (EBSD) data (https://doi.org/10.18434/mds2-2767). Material property data such as elastic mechanical properties are not provided.

The following data files include microstructure measurement results associated with the 2022 Additive Manufacturing Benchmark test series (AM-Bench 2022) AMB2022-01 benchmark on laser powder bed fusion (LPBF) 3D builds of nickel-based superalloy IN718 test objects. The AM builds were performed on the NIST Additive Manufacturing Metrology Testbed (AMMT) and the microstructure measurements were conducted using scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultra-small-angle X-ray scattering (USAXS), small-angle X-ray scattering (SAXS), wide-angle X-ray scattering (WAXS), and automated serial sectioning. Detailed descriptions of the build process parameters, scan pattern, heat treatment, and descriptions of all of the AMB2022-01 measurements are provided on the AMB2022-01 challenge description webpage (https://www.nist.gov/ambench/amb2022-01-benchmark-measurements-and-challenge-problems).Due to the time-sensitive nature of the AM Bench challenge problems, those measurements and analyses were prioritized. The challenges that this data publication address are:Microstructure (CHAL-AMB2022-01-MS): Histograms of direction-specific grain sizes from specified regions within as-built and heat-treated samples.Phase Evolution (CHAL-AMB2022-01-PE): Formation and evolution of phases and phase fractions, including major precipitates, as a function of time for heat treatments of IN718 from a 2.5 mm leg.The data provided for CHAL-AMB2022-01-PE are preliminary since an additional phase in the as-build material has not yet been positively identified. These data will be updated shortly. Also, additional datasets that are not required for the challenges will be added soon. For updates, please check back here or at www.nist.gov/ambench.

This document is part of a series of reports describing experimental property measurements completed at the National Institute for Petroleum and Energy Research (NIPER) in Bartlesville, Oklahoma, in the 1980s and 1990s. Members of the Bartlesville Thermodynamics Group included William D. "Bill" Good, William V. "Bill" Steele, Bruce E. Gammon, Norris K. Smith, Stephen E. Knipmeyer, An "Andy" Nguyen, Timothy D. Klots, I. A. "Alex" Hossenlopp, Aaron P. Rau, William B. Collier, John F. Messerly, Ann G. Osborn, Susan Lee-Bechtold, Donald G. Archer, Ian R. Tasker, Allan B. Cowell, Michael M. Strube, and the author of this report.