The influence of gas pressure and temperature on the characteristics of aluminium powder produced by a novel low-pressure hot gas atomisation process

ABSTRACT

A new low-pressure hot gas atomisation method exploiting the Venturi phenomenon is presented. The working gas is accelerated into a Venturi nozzle and is mixed with the molten metal that is atomised to transform to fine particles. The current work explores the case of pure aluminium that is atomised by carbon dioxide flowing through the Venturi nozzle, while the effect of operating gas temperature and pressure on the particle diameter distribution is investigated. At low temperatures, there is an almost linear relationship between the particle size and the gas pressure with a trend to produce smaller particles at higher gas pressures. This trend cannot be generalised at higher temperatures. The finer powder with average diameter d₅₀ of 129 µm and diametric range ΔH of 362 µm was produced at an operating gas pressure of 3 × 10⁵  Pa (3 bar) and temperature of 903.15 K (630°C).

KEYWORDS:

• Low-pressure hot gas atomisation
• Venturi nozzle
• aluminium particles
• size distribution

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Research Committee, Aristotle University of Thessaloniki [Grant Number 89251].

Notes on contributors

Michail Tsirlis

Michail Tsirlis is Doctor Engineer of the Physical Metallurgy Laboratory (PML), Department of Mechanical Engineering, School of Engineering, Aristotle University of Thessaloniki (AUTH), Greece. He studied Mechanical Engineering and Aeronautics at the University of Patras and received his MSc in Hydromechanics of the Civil Engineering Department, Democritus University of Thrace, Greece. His research interests include the production and characterization of metallic powders and fluid mechanics.

Nikolaos Michailidis

Nikolaos Michailidis is Professor and Director of the Physical Metallurgy Laboratory (PML), Department of Mechanical Engineering, School of Engineering, Aristotle University of Thessaloniki (AUTH), Greece. He is also Research Professor at Texas A&M Engineering Experiment Station (TEES), President of the Hellenic Metallurgical Society (HMS), Chair of the Centre for Research & Development οn Advanced Materials – a Joint initiative between TEES and AUTH and co-founder of PLiN Nanotechnology S.A. (AUTH's spin-off). He is Fellow of the International Academy for Production Engineering (CIRP), member of various Scientific Societies and Boards, Chair of the Scientific Committee of EUROMAT 2019, Member of the Executive Committee of the Federation of European Materials Societies (FEMS) and Editor-in-Chief of the European Journal of Materials by Taylor & Francis and FEMS. He served as Director of the Interdepartmental Post Graduate Studies Program: ‘Processes & Technology of Advanced Materials’ – AUTH and as Chair of the Design & Construction Division (School of Mechanical Engineering-AUTH), while he was Visiting Professor at Fraunhofer Institute for Production Technology (IPT), Aachen-Germany.