气体调控对EIGA制备镍基和钛合金粉末特性的影响

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

摘要:

电极感应熔炼气雾化（electrode induction-melting gas atomization，EIGA）作为无坩埚制粉技术，是超纯净金属粉末制备的关键方法。以镍基高温合金FGH96和钛合金TC4为对象，通过雾化试验与粉末特性表征，研究了雾化压力与气体温度对粉末粒度、粒形及空心粉含量的影响。结果表明，在气体温度25 ℃条件下，随着雾化压力从2.5 MPa升至4.0 MPa，高温合金粉末中值粒径D₅₀由96.3 μm减小至75.5 μm，在雾化压力3.5 MPa时球形度达到0.9805，粉末体积孔隙率也呈现先升后降变化规律。雾化压力4.0 MPa下，气体温度升至100 ℃后，粉末进一步细化，FGH96和TC4粉末的D₅₀分别降至63.8和86.0 μm，且高温合金粉末细化更为显著。高温合金粉末球形度基本保持稳定，钛合金粉末球形度小幅升高，粉末体积孔隙率小幅增加。由于不同合金熔体的粘度、表面张力和密度差异，导致粒度、粒形等粉末特性呈现不同的变化规律。本研究为不同类型合金粉末制备工艺的定制化提供了理论依据。

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.