TY - JOUR

T1 - High-Temperature Nanoindentation of an Advanced Nano-Crystalline W/Cu Composite

AU - Burtscher, Michael

AU - Zhao, Mingyue

AU - Kappacher, Johann

AU - Leitner, Alexander

AU - Wurmshuber, Michael

AU - Pfeifenberger, Manuel J.

AU - Maier-Kiener, Verena

AU - Kiener, Daniel

N1 - Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2021/11/3

Y1 - 2021/11/3

N2 - The applicability of nano-crystalline W/Cu composites is governed by their mechanical properties and microstructural stability at high temperatures. Therefore, mechanical and structural investigations of a high-pressure torsion deformed W/Cu nanocomposite were performed up to a temperature of 600 °C. Furthermore, the material was annealed at several temperatures for 1 h within a high-vacuum furnace to determine microstructural changes and surface effects. No significant increase of grain size, but distinct evaporation of the Cu phase accompanied by Cu pool and faceted Cu particle formation could be identified on the specimen′s surface. Additionally, high-temperature nanoindentation and strain rate jump tests were performed to investigate the materials mechanical response at elevated temperatures. Hardness and Young′s modulus decrease were noteworthy due to temperature-induced effects and slight grain growth. The strain rate sensitivity in dependent of the temperature remained constant for the investigated W/Cu composite material. Also, the activation volume of the nano-crystalline composite increased with temperature and behaved similar to coarse-grained W. The current study extends the understanding of the high-temperature behavior of nano-crystalline W/Cu composites within vacuum environments such as future fusion reactors.

AB - The applicability of nano-crystalline W/Cu composites is governed by their mechanical properties and microstructural stability at high temperatures. Therefore, mechanical and structural investigations of a high-pressure torsion deformed W/Cu nanocomposite were performed up to a temperature of 600 °C. Furthermore, the material was annealed at several temperatures for 1 h within a high-vacuum furnace to determine microstructural changes and surface effects. No significant increase of grain size, but distinct evaporation of the Cu phase accompanied by Cu pool and faceted Cu particle formation could be identified on the specimen′s surface. Additionally, high-temperature nanoindentation and strain rate jump tests were performed to investigate the materials mechanical response at elevated temperatures. Hardness and Young′s modulus decrease were noteworthy due to temperature-induced effects and slight grain growth. The strain rate sensitivity in dependent of the temperature remained constant for the investigated W/Cu composite material. Also, the activation volume of the nano-crystalline composite increased with temperature and behaved similar to coarse-grained W. The current study extends the understanding of the high-temperature behavior of nano-crystalline W/Cu composites within vacuum environments such as future fusion reactors.

KW - <p>W/Cu composite</p>

KW - high-pressure torsion

KW - microstructure

KW - nanocrystalline

KW - nanoindentation

KW - W/Cu composite

KW - High-pressure torsion

KW - Nanoindentation

KW - Microstructure

KW - Nanocrystalline

UR - http://www.scopus.com/inward/record.url?scp=85118338593&partnerID=8YFLogxK

U2 - 10.3390/nano11112951

DO - 10.3390/nano11112951

M3 - Article

VL - 11

JO - Nanomaterials

JF - Nanomaterials

SN - 2079-4991

IS - 11

M1 - 2951

ER -