Abstract: To study the processes of multiscale structure formation far from thermodynamic equilibrium, a series of experiments concerning impact loading of aluminum alloy targets has been carried out by nanosecond pulses initiated by a propelling device and a pulsed electron beam. In both cases, large-scale structures of the mesoscopic level have been revealed in the near-contact region of shock loading, the sizes of which decrease with increasing target thickness, while the target material becomes homogeneous. Transition to a homogeneous structure in aluminum 1565 occurs at a target thickness of 2.2 mm with simultaneous change in the macroscopic response (spall strength) of the material for impact loading.