Evolution of Microstructure and Mechanical Properties of NiCoCrAlY Coatings After High-Current Pulsed Electron Beam Irradiation

Abstract

In this paper, the NiCoCrAlY coating prepared by laser cladding was modified by a high-current pulsed electron beam technique. Scanning electron microscopy and X-ray diffraction analysis were used to characterize the microstructure and composition of the coatings before and after irradiation, and then the changes in mechanical properties were revealed by comparing the hardness and friction properties of the two coatings. The results showed that the pulsed irradiation purified the coating surface, formed an evaporative recondensation layer and a plastic deformation layer, and produced a dense remelting layer with a thickness of 3–4 µm. The remelted layer led to an increase in the hardness of the irradiated coating and a decrease in the friction coefficient and wear. The pulsed irradiation effectively improved the mechanical properties of the coatings.

Fig. 11 Frictional wear diagram of NiCoCrAlY coating.