A multi-scale algorithm for dislocation creep at elevated temperatures. Issue 1 (January 2021)

• Record Type: Journal Article
• Authors: Yuan, Lichao; Wei, Yujie
• Is Part Of: Theoretical & applied mechanics letters. Volume 11:Issue 1(2021)
• Publication Date: 2021-01
• Subjects: Multi-scale algorithm -- Dislocation glide -- Dislocation climb -- High temperature creep -- Dislocation dynamics; Mechanics, Applied -- Periodicals; Mechanics, Analytic -- Periodicals; Mechanics, Analytic; Mechanics, Applied; Periodicals; 620.1
• DOI: 10.1016/j.taml.2021.100230
• Languages: English
• ISSNs: 2095-0349

Abstract

Highlights: An efficient two-scale algorithm is proposed to simulate dislocation glide and dislocation climb induced creep. The results of power-law creep from our modeling agree well with experimental observations. Abstract: Dislocation creep at elevated temperatures plays an important role for plastic deformation in crystalline metals. When using traditional discrete dislocation dynamics (DDD) to capture this process, we often need to update the forces on N dislocations involving ~ N 2 interactions. In this letter, we introduce a multi-scale algorithm to speed up the calculations by dividing a sample of interest into sub-domain grids: dislocations within a characteristic area interact following the conventional way, but their interaction with dislocations in other grids are simplified by lumping all dislocations in another grid as a super one. Such a multi-scale algorithm lowers the computational load to ~ N 1.5 . We employed this algorithm to model dislocation creep in Al-Mg alloy. The simulation leads to a power-law creep rate in consistent with experimental observations. The stress exponent of the power-law creep is a resultant of dislocations climb for ~5 and viscous dislocations glide for ~3.