Structure and phase composition of “ZrO2 thin coating – aluminum substrate” system processed through pulsed electron beam irradiation

[Display omitted] •Tetragonal and monoclinic ZrO2 transforms into cubic one after HCPEBI with Es = 5 J/cm2.•The depth of Al remelted layer nonlinearly depends on the surface energy density Es.•Al partially substitutes Zr in the oxide under HCPEB irradiation.•The mechanism of ZrO2 nanoparticle formation is defined by the energy density Es. Using X-ray, scanning and transmission electron microscopy we studied the variation of the structure and phase composition in the near-surface layer of aluminum covered with thin ZrO2 coating induced by high current pulsed electron beam irradiation with the surface energy densities in the interval of 5.0–10.0 J/cm2. The irradiation with the low energy density is found to transfer monoclinic and tetragonal ZrO2 coating to cubic one. The depth of the remelted aluminum layer nonlinearly depends on the surface energy density. The different formation mechanism of ZrO2 nanoparticles in the near-surface layer for the different energy densities is revealed. Amorphous Al2O3 particles are shown to form on the surface of the irradiated samples due to substitution of zirconium by aluminum in the oxide.