Design of (Hf, Ta)Fe2/Fe composite with zero thermal expansion covering room temperature. (September 2020)

• Record Type: Journal Article
• Authors: Cen, Dongyu; Wang, Bin; Chu, Ruixue; Gong, Yuanyuan; Xu, Guizhou; Chen, Fenghua; Xu, Feng
• Is Part Of: Scripta materialia. Number 186(2020)
• Page Start: 331
• Page End: 335
• Publication Date: 2020-09
• Subjects: zero thermal expansion -- magnetic phase transition -- Hf1-xTaxFe2 compounds -- negative thermal expansion; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2020.05.048
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: MgZn2 -type (Hf, Ta)Fe2 is a typical negative-thermal-expansion system, which expands during the establishment of ferromagnetic ordering in cooling. This abnormal behavior suggests that (Hf, Ta)Fe2 is a potential ingredient to produce a composite with zero thermal expansion. In this work, we find that the as-cast (Hf, Ta)Fe2 have Fe-rich grain boundaries, which disappear after annealing. It inspires us to produce a (Hf, Ta)Fe2 /Fe composite by adding extra Fe in nonstoichiometric composition without annealing. After carefully tuning Hf/Ta ratio and Fe concentration, room-temperature zero-thermal-expansion is achieved in the sample with a composition of Hf0.80 Ta0.20 Fe2.5 . Graphical abstract: Image, graphical abstract