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...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.展开更多
基金support from the National Key Research and Development Program of China (Grant 2017YFB0202800)the National Natural Science Foundation of China, Basic Science Center for “Multiscale Problems in Nonlinear Mechanics” (Grant 11988102)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant XDB22020200)the Chinese Academy of Sciences Center for Excellence in Complex System Mechanics
文摘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.
