An irradiation of materials by an intense pulsed electron beam on the
RITM machine modifies its structural-phase state in the near-surface region. The thin melt of
the material formed on the surface of the target starts cooling at a high rate upon termination of
the pulse. As a result, the melt overcools, thus considerably increasing the probability of solid
phase nucleation, and hence increasing the concentration of the nucleation centres, in other words,
causing refinement of the grains. Upon irradiation, the grain size on the surface can be hundreds or
even tens of nanometers. Thus, the irradiation leads to formation of near-surface nanostructures whose
physical properties are substantially different from those of the coarse-grained structures.
The figure shows a nanostructured surface of a titanium alloy after irradiation.