Inhibited dynamic recovery and screw dislocation annihilation in multiple slip of FCC single crystals

Ladislas Kubin (1) , Benoit Devincre (1) , Thierry Hoc (2)

1 LEM - ONERA - CNRS - Laboratoire d'étude des microstructures [Châtillon]
2 MSSMat - Laboratoire de mécanique des sols, structures et matériaux

In face-centred cubic crystals, the stress-strain curves of crystals exhibit the peculiarity of being remarkably insensitive to dynamic recovery, as compared to other orientations. This effect is attested by several early experimental studies on copper, aluminium and silver crystals. The inhibition of dynamic recovery is attributed to a reduction of the rate of annihilation of screw dislocations. The underlying mechanisms are investigated in terms of the reversal of the direction of the resolved stress in the cross-slip plane, which occurs when going from to orientations. Two distinct processes governing dynamic recovery in crystals, acute cross-slip and backward annihilation, are examined and discussed. The second one arises because screw dislocation annihilation occurs along the direction opposite to that of the resolved applied stress in the cross-slip plane. It is concluded that, except possibly in aluminium, backward annihilation is always responsible for the inhibition of dynamic recovery in crystals.

Mots clés: Physical Sciences

Ladislas Kubin, Benoit Devincre, Thierry Hoc. Inhibited dynamic recovery and screw dislocation annihilation in multiple slip of FCC single crystals. Philosophical Magazine, 2006, 86 (25-26), pp.4023-4036. ⟨10.1080/14786430500525241⟩. ⟨hal-00513653⟩