Features of a nano-twist phase in the nanolayered Ti3AlC2 MAX phase. (15th March 2022)

• Record Type: Journal Article
• Authors: Guénolé, Julien; Taupin, Vincent; Vallet, Maxime; Yu, Wenbo; Guitton, Antoine
• Is Part Of: Scripta materialia. Number 210(2022)
• Publication Date: 2022-03-15
• Subjects: MAX phase -- Air-oxidation -- Twist boundary -- Dislocation -- Disclination -- HR-TEM -- Atomistic modelling; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2021.114425
• Languages: English
• ISSNs: 1359-6462

Abstract

Graphical abstract: Abstract: Complex intermetallic materials known as MAX phases exhibit exceptional properties from both metals and ceramics, largely thanks to their nanolayered structure. With high-resolution scanning transmission electron microscopy supported by atomistic modelling, we reveal atomic features of a nano-twist phase in the nanolayered Ti 3 AlC 2 . The rotated hexagonal single-crystal is encompassed within basal symmetric twist interfaces similar to grain boundaries. In particular, we show that air-oxidation at 1000 ∘ C can form a twisted phase that leads to the formation of interfacial dislocation networks with screw characters or to severe interfacial reconstructions. Additionally, we explore the contribution of disclinations to the representation by continuum models of the stress field generated by such nano-twist defect in the Ti 3 AlC 2 bulk phase. The occurrence of this unexpected defect is foreseen to impact the physical response of this nanolayered-based material and, as such, supports property-by-design approaches.