On the elusive crystal structure of expanded austenite. (1st April 2017)

• Record Type: Journal Article
• Authors: Brink, Bastian K.; Ståhl, Kenny; Christiansen, Thomas L.; Oddershede, Jette; Winther, Grethe; Somers, Marcel A.J.
• Is Part Of: Scripta materialia. Number 131(2017)
• Page Start: 59
• Page End: 62
• Publication Date: 2017-04-01
• Subjects: Expanded austenite -- Crystal structure -- Plastic deformation -- Nitriding -- X-ray diffraction (XRD); Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2017.01.006
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: No consistent structural description exists for expanded austenite that accurately accounts for the hkl -dependent peak shifts and broadening observed in diffraction experiments. The best available description for homogeneous samples is a face-centered cubic lattice with stacking faults. Here Debye simulations of stacking fault effects were compared to experimental data for macro-stress free homogeneous expanded austenite to show that a faulted structure cannot explain the observed peak displacement anomalies. Instead it is argued that the shifts are the combined result of elastic and plastic anisotropy leading to (strongly) non-linear hkl -dependent elastic behavior during composition-induced plastic deformation on synthesis of expanded austenite. Graphical abstract: