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

Authors

Dongyu Cen
Bin Wang
Ruixue Chu
Yuanyuan Gong
Guizhou Xu
Fenghua Chen, University of WollongongFollow
Feng Xu

RIS ID

143605

Publication Details

Cen, D., Wang, B., Chu, R., Gong, Y., Xu, G., Chen, F. & Xu, F. (2020). Design of (Hf,Ta)Fe2/Fe composite with zero thermal expansion covering room temperature. Scripta Materialia, 186 331-335.

Abstract

© 2020 Acta Materialia Inc. 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 Hf0.80Ta0.20Fe2.5.