Pinning of dislocations in disordered alloys: effects of dislocation orientation

Materials Theory

Michael Zaiser¹  Ronghai Wu² 

[1]Department of Materials Simulation, WW8-Materials Simulation, Friedrich-Alexander Universität Erlangen-Nürnberg, Dr.-Mack-str. 77, 90762, Fürth, Germany

[2]School of Mechanics, Civil Engineering and Architecture, Northwestern Polytechnical University, 710129, Xian, People’s Republic of China

关键词: Compositionally complex alloys;    Dislocations;    Critical resolved shear stress;   

DOI  :  10.1186/s41313-021-00036-2

来源: Springer

【 摘 要 】

The current interest in compositionally complex alloys including so called high entropy alloys has caused renewed interest in the general problem of solute hardening. It has been suggested that this problem can be addressed by treating the alloy as an effective medium containing a random distribution of dilatation and compression centers representing the volumetric misfit of atoms of different species. The mean square stresses arising from such a random distribution can be calculated analytically, their spatial correlations are strongly anisotropic and exhibit long-range tails with third-order power law decay (Geslin and Rodney 2021; Geslin et al. 2021). Here we discuss implications of the anisotropic and long-range nature of the correlation functions for the pinning of dislocations of arbitrary orientation. While edge dislocations are found to follow the standard pinning paradigm, for dislocations of near screw orientation we demonstrate the co-existence of two types of pinning energy minima.

【 授权许可】

CC BY