Berlin 2018 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 55: Topical session (Symposium EPS and MM): Mechanical Properties at Small Scales

MM 55.1: Topical Talk

Donnerstag, 15. März 2018, 11:45–12:15, H 0106

Deformation mechanism map of Cu/Nb nanoscale metallic multilayers as a function of temperature and layer thickness — •Jon Molina-Aldareguia¹, Jeromy Snel¹, Miguel Monclús¹, Nathan Mara², Irene Beyerlein³, and Javier Llorca^1,4 — ¹IMDEA Materials Institute, c/Eric Kandel 2, 28906 Getafe (Madrid), Spain — ²University of Minnesota, Minneapolis, MN 55455-0132 — ³University of California, Santa Barbara, CA 93106-5070 — ⁴Universidad Politécnica de Madrid, 28040 Madrid, Spain

The mechanical properties and deformation mechanisms of Cu/Nb nanoscale metallic multilayers (NMMs) manufactured by accumulative roll bonding (ARB) are studied at 25 °C and 400 °C. Cu/Nb NMMs with individual layer thicknesses between 7 and 63 nm were tested by in-situ micropillar compression inside a scanning electron microscope. Yield strength, strain-rate sensitivities and activation volumes were obtained from the pillar compression tests. The deformed micropillars were examined under scanning and transmission electron microscopy in order to examine the deformation mechanisms active for different layer thicknesses and temperatures. A remarkable transition in deformation mechanism occurred at 400 °C as the layer thickness decreased, from dislocation glide to dislocation climb at interfaces, which resulted in temperature-induced softening. A deformation mechanism map, in terms of layer thickness and temperature, is proposed from the results obtained in this investigation.