TY - JOUR
T1 - MC Carbide Characterization in High Refractory Content Powder-Processed Ni-Based Superalloys
AU - Antonov, Stoichko
AU - Chen, Wei
AU - Huo, Jiajie
AU - Feng, Qiang
AU - Isheim, Dieter
AU - Seidman, David N.
AU - Sun, Eugene
AU - Tin, Sammy
N1 - Funding Information:
Financial support for this work was provided by Rolls-Royce Corporation. APT was performed at the Northwestern University Center for Atom-Probe Tomography (NUCAPT). The local-electrode atom-probe tomograph at NUCAPT was acquired and upgraded with equipment grants from the MRI program of the National Science Foundation (Grant Number DMR-0420532) and the DURIP program of the Office of Naval Research (Grant Numbers N00014-0400798, N00014-0610539, N00014-0910781). This work made use of the MatCI Facility at North-western University. NUCAPT and MatCI received support from the MRSEC program (NSF DMR-1121262) at the Materials Research Center, NUCAPT through the SHyNE Resource (NSF NNCI-1542205), and the Initiative for Sustainability and Energy at Northwestern (ISEN). This work made use of the EPIC, Keck-II, and/or SPID facility(ies) of Northwestern University’s NUANCE Center, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205); the MRSEC program (NSF DMR-1121262) at the Materials Research Center; the International Institute for Nanotechnology (IIN); the Keck Foundation; and the State of Illinois, through the IIN. This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
Publisher Copyright:
© 2018, The Minerals, Metals & Materials Society and ASM International.
PY - 2018/6/1
Y1 - 2018/6/1
N2 - Carbide precipitates in Ni-based superalloys are considered to be desirable phases that can contribute to improving high-temperature properties as well as aid in microstructural refinement of the material; however, they can also serve as crack initiation sites during fatigue. To date, most of the knowledge pertaining to carbide formation has originated from assessments of cast and wrought Ni-based superalloys. As powder-processed Ni-based superalloys are becoming increasingly widespread, understanding the different mechanisms by which they form becomes increasingly important. Detailed characterization of MC carbides present in two experimental high Nb-content powder-processed Ni-based superalloys revealed that Hf additions affect the resultant carbide morphologies. This morphology difference was attributed to a higher magnitude of elastic strain energy along the interface associated with Hf being soluble in the MC carbide lattice. The composition of the MC carbides was studied through atom probe tomography and consisted of a complex carbonitride core, which was rich in Nb and with slight Hf segregation, surrounded by an Nb carbide shell. The characterization results of the segregation behavior of Hf in the MC carbides and the subsequent influence on their morphology were compared to density functional theory calculations and found to be in good agreement, suggesting that computational modeling can successfully be used to tailor carbide features.
AB - Carbide precipitates in Ni-based superalloys are considered to be desirable phases that can contribute to improving high-temperature properties as well as aid in microstructural refinement of the material; however, they can also serve as crack initiation sites during fatigue. To date, most of the knowledge pertaining to carbide formation has originated from assessments of cast and wrought Ni-based superalloys. As powder-processed Ni-based superalloys are becoming increasingly widespread, understanding the different mechanisms by which they form becomes increasingly important. Detailed characterization of MC carbides present in two experimental high Nb-content powder-processed Ni-based superalloys revealed that Hf additions affect the resultant carbide morphologies. This morphology difference was attributed to a higher magnitude of elastic strain energy along the interface associated with Hf being soluble in the MC carbide lattice. The composition of the MC carbides was studied through atom probe tomography and consisted of a complex carbonitride core, which was rich in Nb and with slight Hf segregation, surrounded by an Nb carbide shell. The characterization results of the segregation behavior of Hf in the MC carbides and the subsequent influence on their morphology were compared to density functional theory calculations and found to be in good agreement, suggesting that computational modeling can successfully be used to tailor carbide features.
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U2 - 10.1007/s11661-018-4587-2
DO - 10.1007/s11661-018-4587-2
M3 - Article
AN - SCOPUS:85044931317
VL - 49
SP - 2340
EP - 2351
JO - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
JF - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
SN - 1073-5623
IS - 6
ER -