PPT Slide
Lomer-Cottrell barriers can be overcome at high stresses and/or temperatures.
However, it has been shown that for the important case of screw dislocations can escape the pile-up by cross slip before the stress is high enough to collapse the barrier.
While the formation of Lomer-Cottrell barriers is an important mechanism in the strain hardening of fcc metals, they do not constitute the chief contribution to strain hardening.