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

Journal article


Publication Details

Author(s): Freund L, Stark A, Kirchmayer A, Schell N, Pyczak F, Göken M, Neumeier S
Journal: Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science
Publisher: SPRINGER
Publication year: 2018
Volume: 49A
Journal issue: 9
Pages range: 4070-4078
ISSN: 1073-5623


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.


FAU Authors / FAU Editors

Freund, Lisa
Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)
Göken, Mathias Prof. Dr.
Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)
Kirchmayer, Andreas
Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)
Neumeier, Steffen Dr.-Ing.
Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)


External institutions with authors

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


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.

BibTeX: 

Last updated on 2019-06-01 at 12:10