Nanoindentation into a bcc high-entropy HfNbTaTiZr alloy-an atomistic study of the effect of short-range order.

Autor: Alhafez IA; Institute of Applied Mechanics, Clausthal University of Technology, Adolph-Roemer Str. 2A, 38678, Clausthal-Zellerfeld, Germany., Deluigi OR; CONICET and Facultad de Ingeniería, Universidad de Mendoza, Mendoza, 5500, Argentina., Tramontina D; CONICET and Facultad de Ingeniería, Universidad de Mendoza, Mendoza, 5500, Argentina., Merkert N; Institute of Applied Mechanics, Clausthal University of Technology, Adolph-Roemer Str. 2A, 38678, Clausthal-Zellerfeld, Germany., Urbassek HM; Physics Department and Research Center OPTIMAS, University of Kaiserslautern-Landau, Erwin-Schrödinger-Straße, 67663, Kaiserslautern, Germany. urbassek@rhrk.uni-kl.de., Bringa EM; CONICET and Facultad de Ingeniería, Universidad de Mendoza, Mendoza, 5500, Argentina.; Centro de Nanotecnología Aplicada, Facultad de Ciencias, Universidad Mayor, Santiago, 8580745, Chile.
Jazyk: angličtina
Zdroj: Scientific reports [Sci Rep] 2024 Apr 20; Vol. 14 (1), pp. 9112. Date of Electronic Publication: 2024 Apr 20.
DOI: 10.1038/s41598-024-59761-6
Abstrakt: The plastic response of the Senkov HfNbTaTiZr high-entropy alloy is explored by means of simulated nanoindentation tests. Both a random alloy and an alloy with chemical short-range order are investigated and compared to the well understood case of an elementary Ta crystal. Strong differences in the dislocation plasticity between the alloys and the elementary Ta crystal are found. The high-entropy alloys show only little relaxation of the indentation dislocation network after indenter retraction and only negligible dislocation emission into the sample interior. Short-range order-besides making the alloy both stiffer and harder-further increases the size of the plastic zone and the dislocation density there. These features are explained by the slow dislocation migration in these alloys. Also, the short-range-ordered alloy features no twinning plasticity in contrast to the random alloy, while elemental Ta exhibits twinning under high stress but detwins considerably under stress relief. The results are in good qualitative agreement with our current knowledge of plasticity in high-entropy alloys.
(© 2024. The Author(s).)
Databáze: MEDLINE
Externí odkaz: