Surface morphology and defect substructure of the surface layer of Ni₃Al treated by a high-power ion beam

Optical microscopy and transmission electron microscopy were used to study structural transformations that occur in a surface layer (∼0.2 μm thick) of Ni₃Al single crystals upon irradiation with high-power ion beams. The surface relief, phase composition, and defect substructure of this layer were studied as a function of ion-beam power density (Q) ranging between 5 x 10⁷ and 10 x 10⁷ W/cm2. The main factors and mechanisms of the phase and structural surface modification of the alloy under the above treatment conditions were considered using numerically calculated data on the dynamics of the temperature fields and the processes of melting and evaporation of the surface layer.