Aufsatz in einer Fachzeitschrift
Determination of the strain-rate sensitivity of ultrafine-grained materials by spherical nanoindentation
Details zur Publikation
Autor(inn)en: | Feldner, P.; Merle, B.; Göken, M. |
Verlag: | CAMBRIDGE UNIV PRESS |
Publikationsjahr: | 2017 |
Zeitschrift: | Journal of Materials Research |
Seitenbereich: | 1466-1473 |
Jahrgang/Band : | 32 |
Heftnummer: | 8 |
Erste Seite: | 1466 |
Letzte Seite: | 1473 |
Seitenumfang: | 8 |
ISSN: | 0884-2914 |
DOI-Link der Erstveröffentlichung: |
Zusammenfassung, Abstract
The strain-rate sensitivity of the flow stress represents a crucial parameter for characterizing the deformation kinetics of a material. In this work a new method was developed and validated for determining the local strain-rate sensitivity of the flow stress at different plastic strains. The approach is based on spherical nanoindentation strain-rate jump tests during one deformation experiment. In the case of ultrafine-grained Al and ultrafine-grained Cu good agreement between this technique and macroscopic compression tests has been achieved. In contrast to this, individual spherical nanoindentation experiments at constant strain-rates resulted in unrealistically high strain-rate sensitivities for both materials because of drift influences. Microstructural investigations of the residual spherical imprints on ultrafine-grained Al and ultrafine-grained Cu revealed significant differences regarding the deformation structure. For ultrafine-grained Cu considerably less activity of grain boundary sliding has been observed compared to ultrafinegrained Al.
The strain-rate sensitivity of the flow stress represents a crucial parameter for characterizing the deformation kinetics of a material. In this work a new method was developed and validated for determining the local strain-rate sensitivity of the flow stress at different plastic strains. The approach is based on spherical nanoindentation strain-rate jump tests during one deformation experiment. In the case of ultrafine-grained Al and ultrafine-grained Cu good agreement between this technique and macroscopic compression tests has been achieved. In contrast to this, individual spherical nanoindentation experiments at constant strain-rates resulted in unrealistically high strain-rate sensitivities for both materials because of drift influences. Microstructural investigations of the residual spherical imprints on ultrafine-grained Al and ultrafine-grained Cu revealed significant differences regarding the deformation structure. For ultrafine-grained Cu considerably less activity of grain boundary sliding has been observed compared to ultrafinegrained Al.
