Publication: Sulfur-induced embrittlement of nickel: a first-principles study
No Thumbnail Available
Open/View Files
Date
2012
Published Version
Journal Title
Journal ISSN
Volume Title
Publisher
IOP Publishing
The Harvard community has made this article openly available. Please share how this access benefits you.
Citation
Schusteritsch, Georg, and Efthimios Kaxiras. 2012. “Sulfur-Induced Embrittlement of Nickel: A First-Principles Study.” Modelling and Simulation in Materials Science and Engineering 20 (6): 65007. https://doi.org/10.1088/0965-0393/20/6/065007.
Research Data
Abstract
We study the embrittlement of Ni due to the presence of S impurities, considering their effect in the bulk and at grain boundaries (GBs). For bulk Ni, we employ Rice's theory based on generalized-stacking-fault energetics and the unstable stacking energy criterion. We use first-principles density-functional-theory calculations to determine the ductility parameter D = gamma(s)/gamma(us), the ratio of the surface energy gamma(s) to the unstable stacking energy gamma(us), for bulk Ni with substitutional S impurities. Similar arguments based on Rice's theory for the mechanical properties of GBs are invoked. We study the Sigma 5(0 12) GB with interstitial S impurities, in which case D is defined as the ratio of the work of separation W-s and the unstable stacking energy gamma(us), to model the competition between grain decohesion and shear-induced plastic deformation due to grain boundary sliding (GBS). The presence of S impurities is found to increase the value of D by similar to 40% in bulk Ni, but reduces it by over 80% for the GB. These results support earlier suggestions that embrittlement of Ni by S impurities is related to their effect on GBs. We further calculate relevant tensile and shear stresses to study the expected fracture mode and find that intergranular crack propagation accommodated by GBS is inhibited in the system considered here.
Description
Other Available Sources
Keywords
Terms of Use
Metadata Only