Interface dominated mechanical properties of ultra-fine grained and nanoporous Au at elevated temperatures

Temperature-dependent nanoindentation response of materials

“…[33] Nanoporous (NP) Au Increase of hardness up to 100°C, then decrease up to 300°C, explained by the substantial reduction of mobile dislocations upon annealing of the foam, as dislocations are able to exit at free surfaces. [85] Ultra-fine porous Cu Increase of hardness and Young's modulus with temperature, due to oxidation of the top of the ligaments which hinders dislocations to exit from the surface and dislocations are piled-up at the oxide-metal interface. [86] Nanocrystalline (NC) Ni-W Less pronounced thermal softening at finer grain sizes, e.g., 3 nm.…”

Advanced Nanoindentation Testing for Studying Strain-Rate Sensitivity and Activation Volume

“…Since nanoindentation testing is a common tool to probe mechanical properties and is not limited anymore to ambient conditions, several methods and protocols can also be used for high-temperature testing. Results of both nanoindentation strain-rate jump tests 8 , 17 , 35 , 68 as well as nanoindentation creep tests 26 – 28 , 34 are reported over a wide range of temperatures and strain-rates, shedding more light on local thermally activated deformation processes. High temperature testing, however, leads to further challenges regarding thermal stability and testing procedures.…”

“…Due to the limited amount of required material, especially the severe plastic deformation (SPD) 4 and thin film 5 , 6 communities used nanoindentation to gain information on the microstructure dependent deformation behavior of many face-centered cubic (FCC), 7 – 16 body-centered cubic (BCC), 17 – 21 and some hexagonal closed packed (HCP) 22 – 25 metals. Also the SRS of nanocomposites such as Cu-Nb, 26 nanoporous Cu and Au, 27 , 28 or nowadays high-entropy alloys (HEA) 29 , 30 were successfully investigated by nanoindentation. Besides the successful determination of positive SRS, few studies report experiments and results of negative SRS.…”

Impact of interfaces on the radiation response and underlying defect recovery mechanisms in nanostructured Cu-Fe-Ag

“…Extensive research has also been performed in recent years to investigate the behavior of nanoporous metal foams under irradiation and it was found that the vast amount of free surface in these materials acts as perfect defect sink [13,14,17,18,20,27]. As has been demonstrated for the Cu-Fe [45] and Au-Fe system [46], fabrication of nanoporous materials can be realized by selective etching of a composite material consisting of two or more metals with a large difference in electrochemical potential. For certain material combinations, the etching process has to be conducted with an applied protective potential (potentiostatic dealloying) to ensure only dissolution of one component and protection of the desired components [47][48][49][50][51][52].…”