Effects of Gas Regulation on the Characteristics of Nickel-Based and Titanium Alloy Powders Prepared by EIGA

Abstract:

Electrode induction-melting gas atomization (EIGA) is a crucial technique for producing ultra-high-purity metal powders, as it is a crucible-free powder production method. This study focused on the nickel-based superalloy FGH96 and the titanium alloy TC4, and the effects of atomization pressure and gas temperature on the particle size, morphology, and hollow powder content of the alloys were investigated. The study combined atomization experiments with powder characterization. The results show that at a gas temperature of 25 ℃, increasing the atomization pressure from 2.5 MPa to 4.0 MPa reduces the median particle size (D₅₀) from 96.3 μm to 75.5 μm. The sphericity reaches 0.9805 at an atomization pressure of 3.5 MPa. The powder volume porosity also exhibits a trend of first increasing and then decreasing. At an atomization pressure of 4.0 MPa, when the gas temperature increases to 100 ℃, the powders are further refined, with the D₅₀ values for FGH96 and TC4 powders decreasing to 63.8 and 86.0 μm, respectively. The gas heating effect is more pronounced for the superalloy powders. As the gas temperature rises, the powder sphericity of the superalloy remains unchanged, while the powder sphericity of the titanium alloy increases slightly. The powder volume porosity of the superalloy slightly increases. Due to differences in viscosity, surface tension, and density between the two alloy melts, powder characteristics such as particle size and morphology exhibit distinct variation trends. This study provides a theoretical basis for the customization of powder preparation processes for different types of alloys.