Features of the morphology, defect substructure, and phase composition of metal and alloy surfaces upon high-power ion beam irradiation

Optical metallography, transmission electron microscopy, and phase analysis were used to study the mechanisms of structural transformations in the surface layer of thickness Δh≈0.2 μm for single crystals and polycrystals of metals and alloys irradiated with high-power ion beams (HPIBʹs). Characteristic features of the formation of the surface relief and variations in phase constitution and defect substructure of pure metals (Ni, Mo) and single-phase (Mo–Re, Ni3Al) and double-phase (V–ZrO2) alloys have been found in relation to the ion beam power density Q=(1–10)×107 W/cm2. Common features and distinctions in the formation of the microstructure of metallic materials belonging to different classes under HPIB irradiation have been revealed. Based on the predictions of a numerical simulation of the time-dependent temperature fields and the melting and evaporation processes in the surface layer, the mechanisms for the phase-structure modification of metal and alloy surfaces are analyzed.