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Shock loading of M3 copper within strain rate range of 5·106 - 5,7·106
s-1 reveals a nucleation of structural objects of 5-30 µm in diameter, which present the
three dimensional frameworks composed from shear bands of 50-200 nm spacing. The structures are shown
to be nucleated by means of interference of longitudinal and periphery release waves. Transition of
the material into structure unstable state responsible for the shear banding happens when rate of
change of the velocity variance at the mesoscale becomes higher than the rate of change of the mean
particle velocity. The sites of nucleation of 3D-structures are speculated to be the staking faults
generated under action of chaotic velocity pulsations relevant to dynamic deformation. The physical
model for formation of 3D-structures takes into account the intersection of the partial dislocations
and Lomer - Cottrell barriers.
Keywords: shock loading; shear bands; stacking fault; partial dislocations; framework structures. |
full paper (pdf, 2240 Kb)