Peculiarities of dislocation motion in aluminum with allowance for the Peierls relief in the presence of ultrasound

Resumo

The effect of ultrasound on motion of the Frenkel–Kontorova dislocations in aluminum has been studied with inclusion of the Peierls relief. A dislocation moves at a variable rate when overcoming the Peierls barrier. The dislocation mean free path is changed under action of ultrasound at various frequencies comparable to the dislocation transition time to a neighboring valley. The stress–strain dependences have been obtained for high and low strain rates. In both the cases, a disordering takes place; however, the disordering rates and characters are different. At the resonance frequency, the strain resistance decreases, the hardening stage is shortened and the disordering stage is elongated. The dependence of the coefficient of hardening on coordinate has three segments different in characters. The coefficient of hardening decreases at the resonance frequency.