Abstract
Abstract
Though it is well known that initial dislocation microstructures play an important role in the deformation behavior of materials, how dislocation microstructures affect the macroscopic properties is still subjected to intensive research due to their complexity. In this work, we use discrete dislocation dynamics (DDD) to understand the effect of initial dislocation microstructures on the dynamic yield behavior of single-crystal tungsten above the critical temperature (800 K). DDD results suggest that the dislocation source length
l
0
and the dislocation density
ρ
0
are responsible for the initial yield stress and the flow stress of tungsten under dynamic loading, respectively. As
ρ
0
and
l
0
increase, the plastic yield mechanism transforms from dislocation-source activation into dislocation-dislocation interactions, resulting in the initial yield stress decreasing and the flow stress increasing. The confluent effects of
ρ
0
and
l
0
on the steady-state flow stress
σ
flow
can be unified by a linear relationship between
σ
flow
and
ρ
0
log
l
0
2
b
.
Our results could be a valuable piece that connects dynamic yield behavior to the initial dislocation microstructures.
Funder
National Supercomputer Center in Tianjin
National Natural Science Foundation of China
Science Challenge Project
Subject
Condensed Matter Physics,Mathematical Physics,Atomic and Molecular Physics, and Optics