Gas Atomization of Aluminium Melts: Comparison of Analytical Models

Abstract

A number of analytical models predicting the size distribution of particles during atomization of Al-based alloys by N 2 , He and Ar gases were compared. Simulations of liquid break up in a close coupled atomizer revealed that the finer particles are located near the center of the spray cone. Increasing gas injection pressures led to an overall reduction of particle diameters and caused a migration of the larger powder particles towards the outer boundary of the flow. At sufficiently high gas pressures the spray became monodisperse. The models also indicated that there is a minimum achievable mean diameter for any melt/gas system.

The identification of an accurate simulation approach to predict the effect of operational parameters on the particle size distribution (PSD) of powders produced by an industrial close-coupled gas atomiser

“…The potential emergence of Additive Layer Manufacturing (ALM) into the mainstream of bespoke part production highlights the importance of manufacturing fine, spherical, metal powders that meet any pre-defined specifications. Gas atomisation is a complex multi-physics process which involves a molten metal stream passing through an atomising nozzle system, in which high velocity jets of an inert atomising gas impinge upon the stream resulting in its disintegration into fine droplets [1,2,3]. It is extensively used as an efficient manufacturing method for high quality powders, as required for ALM production.…”

Plasma-spray synthesis and characterization of ti-based nitride and oxide nanogranules

“…The distribution of particle sizes for the case of the Ti-N system is presented in Figure 5b, as measured by the size analyser. Dverall, the effect of the radial injection point of the gas upon the nanocrystalline particle diameter followed the gas density and was on par with gas compressibility as previously calculated in the case of two-phase flows [17][18][19]21 . When argon was used as the working gas and oxygen as the reaction gas, an oxygendeficient oxide nanocrystal was formed, as detected by X-ray diffraction (see Figure 1a), while sub-stoichiometric material required further processing for complete oxidation; such post processing involved annealing of the powders in ambient conditions.…”

Laboratory-scale gas atomizer for the manufacturing of metallic powders

“…Each sub-process affects the quality of the produced powder. The PSD of the powder are determined by two-phase turbulent effects between melt and gas flows and the heat transfer during solidification [10]. The median volume-weighted particle size diameter has been correlated with the opening of the ceramic pouring tube ´𝑑𝑚𝑒𝑙𝑡 ´, as [11,12]:…”