From unlikely pairings to functional nanocomposites: FeTi–Cu as a model system

Author(s)

Lukas Schweiger, Daniel Kiener, Michael Burtscher, Erhard Schafler, Gregor Mori, Florian Spieckermann, Jürgen Eckert

Abstract

In order to develop materials for energy storage, a bulk nanocomposite with a composition of FeTi-25 vol% Cu was prepared by high-pressure torsion, with FeTi as functional phase for hydrogen storage and Cu as ductile phase to improve the processability. Despite the use of such a highly ductile auxiliary phase, the processability remained challenging due to strain localization in the softer Cu. This behavior is most pronounced at room temperature, and no nanocomposites were formed. At elevated temperatures, the strong strain rate sensitivity of the flow stress of the nanocrystalline Cu facilitates the formation of a FeTi–Cu nanocomposite due to a self-reinforcing process. Nevertheless, fragmentation of FeTi is limited because the resulting massive strain hardening prevents controlled processing at temperatures 250 °C. Satisfactory microstructural homogeneity is only achieved at the highest deformation temperatures of 550 °C. Overall, this study highlights that for unlikely material pairings, as often required in the pursuit of superior functional materials, the mechanical behavior of the phases involved and their interplay remains critical and must be thoroughly investigated when aiming for controlled structural homogeneity of bulk nanomaterials.

Organisation(s)

Dynamics of Condensed Systems

External organisation(s)

Montanuniversität Leoben, Österreichische Akademie der Wissenschaften (ÖAW)

Journal

Materials Today Advances

Volume

20

No. of pages

13

ISSN

2590-0498

DOI

https://doi.org/10.1016/j.mtadv.2023.100433

Publication date

12-2023

Peer reviewed

Yes

Austrian Fields of Science 2012

103018 Materials physics, 210004 Nanomaterials

Keywords

ASJC Scopus subject areas

General Materials Science, Mechanical Engineering

Portal url

https://ucrisportal.univie.ac.at/en/publications/73192d8d-23e0-428e-927a-c39945f317f1