On the nucleation of planar faults during low temperature and high stress creep of single crystal Ni-base superalloys

Wu X, Dlouhy A, Eggeler Y, Spiecker E, Kostka A, Somsen C, Eggeler G (2017)

Publication Language: English

Publication Type: Journal article

Publication year: 2017

Journal

Acta Materialia Elsevier

DOI: 10.1016/j.actamat.2017.09.063

Abstract

The present work studies the nucleation of planar faults in the early stages of low temperature (750 °C) and high stress (800 MPa) creep of a Ni-base single crystal superalloy (SX). Two families of 60° dislocations with different Burgers vectors were detected in the transmission electron microscope (TEM). These can react and form a planar fault in the γ′ phase. A 2D discrete dislocation model helps to rationalize a sequence of events which lead to the nucleation of a planar fault. First, one 60° channel dislocation approaches another 60° interface dislocation with a different Burgers vector. At a distance of 5 nm, it splits up into two Shockley partials. The interface dislocation is pushed into the γ′-phase where it creates a small antiphase boundary. It can only move on when the leading Shockley partial joins it and creates an overall 1/3<112> superdislocation. This process is fast and therefore is difficult to observe. The results obtained in the present work contribute to a better understanding of the processes which govern the early stages of low temperature and high stress primary creep of SX.

Authors with CRIS profile

Yolita Eggeler Sonderforschungsbereich 953/3 Synthetische Kohlenstoffallotrope Erdmann Spiecker Lehrstuhl für Werkstoffwissenschaften (Mikro- und Nanostrukturforschung)

Additional Organisation(s)

Lehrstuhl für Werkstoffwissenschaften (Mikro- und Nanostrukturforschung) Interdisziplinäres Zentrum, Center for Nanoanalysis and Electron Microscopy (CENEM)

Involved external institutions

Ruhr-Universität Bochum (RUB) DE Germany (DE)

How to cite

APA:

Wu, X., Dlouhy, A., Eggeler, Y., Spiecker, E., Kostka, A., Somsen, C., & Eggeler, G. (2017). On the nucleation of planar faults during low temperature and high stress creep of single crystal Ni-base superalloys. Acta Materialia. https://doi.org/10.1016/j.actamat.2017.09.063

MLA:

Wu, X., et al. "On the nucleation of planar faults during low temperature and high stress creep of single crystal Ni-base superalloys." Acta Materialia (2017).

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