Electro-dislocation multiplication and strain effect in2091Al-Li alloy①
(Mechanical Department, Petroleum University (East China), Dongying257062, P.R.China)
Abstract: Electro-dislocation multiplication and strain effect were investigated. TEM observation showed that when statically held for 15 min, the microstructure of dislocation cell in the specimens without current pulse turned to subgrains with few dislocations in cold rolled state, but when current pulse charged, there were a lot of dislocations although a more rapid recrystallization occurred concurrently; when deformed, the interior dislocations in the specimens without current
pulse were annihilated due to dynamic recrystallization, but were not decreased in the current pulse charged specimens in dynamic recrystallization, instead increased. It is indicated that“electron wind”force created by current pulse produced a shear stress for dislocation slip, and caused a dislocation multiplication in static holding of 2091 Al-Li alloy; when strain exerted, an additional shear stress was provided to increase the effect of current pulse on dislocation multiplication.
pulse were annihilated due to dynamic recrystallization, but were not decreased in the current pulse charged specimens in dynamic recrystallization, instead increased. It is indicated that“electron wind”force created by current pulse produced a shear stress for dislocation slip, and caused a dislocation multiplication in static holding of 2091 Al-Li alloy; when strain exerted, an additional shear stress was provided to increase the effect of current pulse on dislocation multiplication.
Key words: Al-Li alloy; deformation; dislocation multiplication; current pulse