Effect of irradiation pulses on the microstructure and phase composition of NiCoCrAlYlaser cladding coating under the action of high-current pulsed electron beam

To reduce the number of microcracks and pores on the surface of laser cladding layers, we used a novel, to the best of our knowledge, surface alloying method to modify the surface of a NiCoCrAlY laser cladding coating using high-current pulsed electron beam technology. The x-ray diffraction peaks of the irradiated coatings were affected by the residual stress, which caused the peaks to shift and significantly broaden. With an increase in the number of pulses, the cleaning effect of the coating surface became significant. At the same time, the degree of surface alloying increased, and different degrees of slip were formed on the surface of the coating. There were many nanocrystals accumulated at the slip angle, and the grain size of the coating surface increased.