The effect of phosphorus on the formation of grain boundary laves phase in high-refractory content Ni-based superalloys

Journal Article · Fri Mar 01 00:00:00 EST 2019 · Scripta Materialia

DOI:https://doi.org/10.1016/j.scriptamat.2018.10.015· OSTI ID:1530611

Antonov, Stoichko ^[1]; Chen, Wei ^[2]; Lu, Song ^[3]; Isheim, Dieter ^[4]; Seidman, David N. ^[4]; Feng, Qiang ^[3]; Sun, Eugene ^[5]; Tin, Sammy ^[2]

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1. Univ. of Science and Technology, Beijing (China). Beijing Advanced Innovation Center for Materials Genome Engineering, State Key Lab. for Advanced Metals and Materials; Illinois Inst. of Technology, Chicago, IL (United States)
2. Illinois Inst. of Technology, Chicago, IL (United States)
3. Univ. of Science and Technology, Beijing (China). Beijing Advanced Innovation Center for Materials Genome Engineering, State Key Lab. for Advanced Metals and Materials
4. Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering; Northwestern Univ. Center for Atom Probe Tomography (NUCAPT), Evanston, IL (United States)
5. Rolls-Royce Corporation, Indianapolis, IN (United States)

The effect of phosphorous on the microstructure of a powder-processed, high Nb-content, Ni-based superalloy was studied and compared to a P-free variant. The P-doped sample had a lower incipient melting temperature, forming a (Ni, Co, Cr, P)₂(Nb, Mo) laves phase along the grain boundaries. Transmission electron microscopy and atom probe tomography were used to identify the crystal structure, assess phase compositions, and determine any elemental segregation to phase boundaries. The results revealed strong partitioning of P to the laves phase and a slight Mo gradient towards the γ' phrase. Finally, a simplified laves phase was successfully modeled via density functional theory calculations.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: AC02-05CH11231; AC02-06CH11357
• OSTI ID: 1530611
• Journal Information: Scripta Materialia, Vol. 161, Issue C; ISSN 1359-6462
• Publisher: Elsevier
• Country of Publication: United States
• Language: English