Influence of irradiation with a high-intensity pulsed electron beam on mechanical properties and structural states of coatings formed by plasma spraying

The purpose of the present studies is to establish the formation patterns of the structure and properties of the surface layer of 060A35 steel modified using a combined method that includes plasma spraying of a powder coating and the subsequent irradiation with an intense pulsed electron beam. Plasma spraying on the surface of a steel powder of the system Ni-Cr-B-Si (PGSR-4 with a fraction of 80-100 μm) was performed on the original installation equipped with two plasma generators. The irradiation of the modified steel layer was carried out with an intense pulsed electron beam on the installation SOLO. The investigation of the phase and elemental composition, the state of the defective substructure were carried out using methods of X-ray phase analysis, optical and scanning electron microscopy. The mechanical properties of the irradiated surface were characterized by microhardness. It is shown that plasma spraying of a powder coating leads to formation of a high-relief surface containing micro- and macropores. The subsequent treatment of the modified surface with an intense pulsed electron beam of a submillisecond duration in the melting mode of the surface layer is accompanied by smoothing of the coating surface, saturation of the crystalline lattice of the surface layer with Ni, Cr, B and Si atoms, formation of dendritic crystallization cells of submicron sizes, release of nanoscale particles of the second phase, formation of a quenching structure. Together, this has allowed to increase the microhardness of the modified layer in 4.6-6.5 times.