Spherical EP741NP alloy powders were prepared by the supreme-speed plasma rotating electrode process (SS-PREP) and argon atomization (AA) process. A comparative study was conducted to investigate the effects of the two powder preparation processes on the powder characteristics. The results show that the EP741NP alloy powders prepared by the SS-PREP process have a more regular morphology

lower contents of hollow powders and irregularly shaped powders

and obvious advantages in physical properties such as oxygen pickup

sphericity and fluidity

but with a larger powder particle size. The powders prepared by the AA process contain more irregular particles

with many satellite particles on the surface of the powder particles

and adhesion between some powders. The surface of the EP741NP alloy powder particles prepared by the SS-PREP process exhibits a typical dendritic structure that grows in a radial pattern. The surface structure of the powders prepared by the AA process is unclear

a small amount of dendrites can be observed locally

and there are more hollow powder particles and individual powders with abnormal microstructures in the powders. The internal pores of the hollow powders are completely enclosed

and the inner surface of the pores is not smooth

showing a flocculent and irregular morphology. This phenomenon is mainly attributed to the incomplete breakup of the liquid film caused by the impact of the atomizing gas; The atomizing gas gets entrapped

and the internal atomizing gas does not escape before the pouch-shaped liquid film collapses

thereby forming hollow powders. At the test temperatures of room temperature

650 ℃ and 750 ℃

the tensile properties of the EP741NP alloys fabricated from the two types of powders exhibit consistent trends in tensile properties

with the tensile strength and yield strength of the powders prepared by the SS-PREP method higher than those prepared by the AA process.