TY - JOUR
T1 - Absence of dynamic strain aging in an additively manufactured nickel-base superalloy
AU - Beese, Allison M.
AU - Wang, Zhuqing
AU - Stoica, Alexandru D.
AU - Ma, Dong
N1 - 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. A.M.B. acknowledges funding from the Oak Ridge Associated Universities Ralph E. Powe Junior Faculty Enhancement Award. AMIN625 samples were fabricated at Penn State’s Center for Innovative Materials Processing through Direct Digital Deposition (CIMP-3D). The research at Oak Ridge National Laboratory’s Spallation Neutron Source was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. Matthew Frost and Harley Skorpenske are acknowledged for their technical support.
Publisher Copyright:
© 2018 The Author(s).
PY - 2018/12/1
Y1 - 2018/12/1
N2 - Dynamic strain aging (DSA), observed macroscopically as serrated plastic flow, has long been seen in nickel-base superalloys when plastically deformed at elevated temperatures. Here we report the absence of DSA in Inconel 625 made by additive manufacturing (AM) at temperatures and strain rates where DSA is present in its conventionally processed counterpart. This absence is attributed to the unique AM microstructure of finely dispersed secondary phases (carbides, N-rich phases, and Laves phase) and textured grains. Based on experimental observations, we propose a dislocation-Arrest model to elucidate the criterion for DSA to occur or to be absent as a competition between dislocation pipe diffusion and carbide-carbon reactions. With in situ neutron diffraction studies of lattice strain evolution, our findings provide a new perspective for mesoscale understanding of dislocation-solute interactions and their impact on work-hardening behaviors in high-Temperature alloys, and have important implications for tailoring thermomechanical properties by microstructure control via AM.
AB - Dynamic strain aging (DSA), observed macroscopically as serrated plastic flow, has long been seen in nickel-base superalloys when plastically deformed at elevated temperatures. Here we report the absence of DSA in Inconel 625 made by additive manufacturing (AM) at temperatures and strain rates where DSA is present in its conventionally processed counterpart. This absence is attributed to the unique AM microstructure of finely dispersed secondary phases (carbides, N-rich phases, and Laves phase) and textured grains. Based on experimental observations, we propose a dislocation-Arrest model to elucidate the criterion for DSA to occur or to be absent as a competition between dislocation pipe diffusion and carbide-carbon reactions. With in situ neutron diffraction studies of lattice strain evolution, our findings provide a new perspective for mesoscale understanding of dislocation-solute interactions and their impact on work-hardening behaviors in high-Temperature alloys, and have important implications for tailoring thermomechanical properties by microstructure control via AM.
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U2 - 10.1038/s41467-018-04473-5
DO - 10.1038/s41467-018-04473-5
M3 - Article
C2 - 29802372
AN - SCOPUS:85047613613
SN - 2041-1723
VL - 9
JO - Nature Communications
JF - Nature Communications
IS - 1
M1 - 2083
ER -