فهرست نشریات علمی دسترسی آزاد ایران

The study investigated the fabrication of NiCoCrAlY intermediate coatings on Inconel 718LC nickel-based superalloy substrates using electrochemical deposition from a Watts bath containing NiCrAlY particles, followed by homogenization treatment. To achieve an optimal particle size, the initial NiCrAlY powder was mechanically milled under an argon atmosphere for 30 hours. The effects of NiCrAlY powder concentration in the electrodeposition bath and current density on the incorporation of co-deposited NiCrAlY particles and coating microstructure were examined. After deposition, the coatings were homogenized at 1100°C for 2 hours in an argon environment to ensure chemical uniformity. The chemical composition, phase structure, morphology, and hardness of the coatings were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and Microhardness testing. Results revealed that low powder concentrations and current densities resulted in limited incorporation of NiCrAlY particles, while increasing these parameters initially enhanced particle incorporation before eventual decline. Homogenization promoted the formation of γ'(Al3Ni) intermetallic phases within the γ (Ni, Co) matrix. The increased incorporation of co-deposited particles improved hardness through solid solution strengthening, γ'(Al3Ni) intermetallic phase formation, and microstructural refinement. The coating deposited at an optimal current density of 20 mA/cm2 and NiCrAlY powder concentration of 20 g/l exhibited the highest hardness.