The Effect of a Grain Boundary Pinning B2 Phase on Polycrystalline Co-Based Superalloys with Reduced Density

Freund L, Stark A, Kirchmayer A, Schell N, Pyczak F, Göken M, Neumeier S (2018)

Publication Status: Published

Publication Type: Journal article

Publication year: 2018

Journal

Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science ASM International

Publisher: SPRINGER

Book Volume: 49A

Pages Range: 4070-4078

Journal Issue: 9

DOI: 10.1007/s11661-018-4757-2

Abstract

The Al/W ratio was increased in a new polycrystalline gamma/gamma' Co-based superalloy in order to introduce a grain boundary pinning phase while at the same time reducing the density and increasing the oxidation resistance. The grain boundary pinning phase was identified as beta-phase (B2-(Ni,Co)Al) by high-energy X-ray diffraction. The grain boundary pinning effect was confirmed to be effective up to temperatures of 1050 degrees C by synchrotron radiation in-situ heating experiments. The precipitation of the beta phase led to a reduced gamma' volume fraction thereby decreasing the high-temperature strength. The density was lowered to 8.52 g/cm(3), so the specific strength was equivalent to the strength of the reference alloy up to 750 degrees C. Due to the low gamma' volume fraction and the low W content, the creep resistance was also reduced compared with the reference alloy. The oxidation resistance, however, was improved by the formation of a thin, continuous Al-oxide layer during oxidation at 900 degrees C for 50 hours.

Authors with CRIS profile

Lisa Freund Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften) Andreas Kirchmayer Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften) Mathias Göken Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften) Steffen Neumeier Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)

Additional Organisation(s)

Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)

Related research project(s)

B03 (FP2): Einkristalline y'-gehärtete Co-Basis-Superlegierungen - Legierungsentwicklung, Gitterfehlpassung und mechanische Eigenschaften (SFB/TRR 103) SFB/TRR 103 Jan. 1, 2016 - Dec. 31, 2019

Involved external institutions

Helmholtz-Zentrum Geesthacht Zentrum für Material- und Küstenforschung GmbH (HZG) DE Germany (DE)

How to cite

APA:

Freund, L., Stark, A., Kirchmayer, A., Schell, N., Pyczak, F., Göken, M., & Neumeier, S. (2018). The Effect of a Grain Boundary Pinning B2 Phase on Polycrystalline Co-Based Superalloys with Reduced Density. Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science, 49A(9), 4070-4078. https://dx.doi.org/10.1007/s11661-018-4757-2

MLA:

Freund, Lisa, et al. "The Effect of a Grain Boundary Pinning B2 Phase on Polycrystalline Co-Based Superalloys with Reduced Density." Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science 49A.9 (2018): 4070-4078.

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