TY - JOUR
T1 - Residual stress mapping in Inconel 625 fabricated through additive manufacturing
T2 - Method for neutron diffraction measurements to validate thermomechanical model predictions
AU - Wang, Zhuqing
AU - Denlinger, Erik
AU - Michaleris, Panagiotis
AU - Stoica, Alexandru D.
AU - Ma, Dong
AU - Beese, Allison M.
N1 - Funding Information:
This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ).
Funding Information:
The authors gratefully acknowledge the financial support of the National Science Foundation through award number CMMI-1402978 . Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation. In addition, AMB acknowledges funding from the Oak Ridge Associated Universities Ralph E. Powe Junior Faculty Enhancement Award . The IN625 samples made by AM were fabricated at the Center for Innovative Materials Processing through Direct Digital Deposition (CIMP-3D). A portion of this research at ORNL's Spallation Neutron Source was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy . We thank Matthew Frost and Harley Skorpenske of ORNL for their technical support at the VULCAN beamline.
Publisher Copyright:
© 2016 Elsevier Ltd
PY - 2017/1/5
Y1 - 2017/1/5
N2 - The rapid solidification and subsequent thermal cycles that material is subjected to during additive manufacturing (AM) of a component result in a buildup of residual stresses, which lead to part distortion, and negatively impact the component's mechanical properties. We present a method for using neutron diffraction to validate thermomechanical models developed to predict the residual stresses in Inconel 625 walls fabricated by laser-based directed energy deposition. Residual stress calculations from neutron diffraction measurements depend strongly on the determination of stress-free lattice spacings. After measurement of stressed lattice spacings in Inconel 625 walls, reference samples were obtained by extracting thin slices from the walls and cutting comb-type slits into these slices. Reference lattice spacings were measured in these slices, as well as equivalent slices that were also subjected to stress-relieving heat treatment. These heat treatments changed the reference lattice spacings, and therefore affected residual strain measurements. Further, this study shows the importance of using location-dependent reference lattice spacing, as during AM, the thermal history, and therefore elemental composition and stress-free lattice spacing, vary with position. Residual stresses measured by neutron diffraction along the build direction using comb-type reference samples without heat treatment were in good agreement with thermomechanical modeling predictions.
AB - The rapid solidification and subsequent thermal cycles that material is subjected to during additive manufacturing (AM) of a component result in a buildup of residual stresses, which lead to part distortion, and negatively impact the component's mechanical properties. We present a method for using neutron diffraction to validate thermomechanical models developed to predict the residual stresses in Inconel 625 walls fabricated by laser-based directed energy deposition. Residual stress calculations from neutron diffraction measurements depend strongly on the determination of stress-free lattice spacings. After measurement of stressed lattice spacings in Inconel 625 walls, reference samples were obtained by extracting thin slices from the walls and cutting comb-type slits into these slices. Reference lattice spacings were measured in these slices, as well as equivalent slices that were also subjected to stress-relieving heat treatment. These heat treatments changed the reference lattice spacings, and therefore affected residual strain measurements. Further, this study shows the importance of using location-dependent reference lattice spacing, as during AM, the thermal history, and therefore elemental composition and stress-free lattice spacing, vary with position. Residual stresses measured by neutron diffraction along the build direction using comb-type reference samples without heat treatment were in good agreement with thermomechanical modeling predictions.
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U2 - 10.1016/j.matdes.2016.10.003
DO - 10.1016/j.matdes.2016.10.003
M3 - Article
AN - SCOPUS:84991688580
SN - 0264-1275
VL - 113
SP - 169
EP - 177
JO - Materials and Design
JF - Materials and Design
ER -