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

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

Additional Organisation(s)

Involved external institutions

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).

BibTeX: Download