Pattern-forming nanoprecipitates in NiTi-related high entropy shape memory alloys. (September 2020)

• Record Type: Journal Article
• Authors: Hinte, Christian; Barienti, Khemais; Steinbrücker, Jan; Gerstein, Gregory; Swider, Mark Alan; Herbst, Sebastian; Eggeler, Gunther; Maier, Hans Jürgen
• Is Part Of: Scripta materialia. Number 186(2020)
• Page Start: 132
• Page End: 135
• Publication Date: 2020-09
• Subjects: Shape memory alloys (SMA) -- High entropy alloys (HEA) -- Electron backscattering patterns (EBSP) -- Interfacial segregation -- Nanocrystalline microstructure; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2020.05.007
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: The microstructure and the fracture behavior of TiZrHfCoNiCu high entropy shape memory alloys with two different compositions were investigated. An unusual microstructure featuring pattern-forming nanoprecipitates was observed in dendritic and the interdendritic regions of both alloys. The unique higher-level order of these precipitates does not follow concentration gradients but is influenced by homogeneity and mechanical stress. The results also demonstrate that high entropy alloys are not necessarily homogeneous single-phase solid solutions. Moreover, it appears that solid solution strengthening as the primary mechanism also has to be questioned. Graphical abstract: Image, graphical abstract