Abstract
•Laser cladding is an attractive and quality method for coating of gas turbine blades.•The application of external fields causes the equiaxed grains to expand.•Expansion of equiaxed grains increases yield strength and hardness.•The magnetic field along with the laser causes the proper distribution of phases.•The electromagnetic field along with the laser increases the absorption of the powder.
In this research, the effect of external electromagnetic and ultrasonic fields was used individually and simultaneously, when the GTD-111 superalloy laser was coated with IN625 powder. The results showed that the application of external fields increases the area of the equiaxed region due to the decrease in a temperature gradient, the creation of heterogeneous nucleation sites, and the dynamic forces that cause the columnar grains to be crushed. In addition, the tendency to form pores is reduced when magnetic and ultrasonic forces are used simultaneously. The average micro-hardness and tensile strength of the cladding layer also increased by 61% and 36%, respectively, when in conditions without and using hybrid external fields.