Numerical analysis of droplet breakup, cooling, and solidification during gas atomisation

ABSTRACT

As gas atomisation has been the main method for producing high-performance spherical powders in the past decades, its application in the production of metallic powders has become one of the main research subjects in this field. Since it is challenging to directly observe the atomising gas and to investigate melt flow states by experiments, numerical simulation is attracting increasing interest in studying the gas atomisation process. In this work, various computational fluid dynamics models were implemented to simulate the gas atomisation process. With the models, the droplet breakup, cooling, and solidification within the coupled process were investigated. The final mean particle size was predicted through numerical simulations and compared with the statistics extracted from the gas atomisation process, which shows that a reasonable mass median diameter of the particle can be predicted numerically. The results also show a clear relationship between the breakup trajectory and the resulting particle size.

KEYWORDS:

• Gas atomisation
• breakup
• cooling
• solidification
• particle size and distribution
• numerical methods
• simulation

Disclosure statement

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

Additional information

Funding

Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy – EXC-2023 Internet of Production – 390621612. Simulations were performed with computing resources granted by RWTH Aachen University under project rwth1281.

Notes on contributors

Gezhou Wang

Gezhou Wang graduated from RWTH Aachen University in 2022 with a Master's degree in Automotive Engineering and Transportation. He studied the gas atomization process with numerical methods at the Institute of Materials Applications in Mechanical Engineering in 2022 and then worked on this topic as a student assistant for a few months before entering the industry.

Yuanbin Deng

Yuanbin Deng currently leads the research in the process simulation field of the powder metallurgy and ceramics at the Institute for Materials Applications in Mechanical Engineering at RWTH Aachen University. His research interests focus on the development of the digital twin of the powder metallurgical processes from powder to component, for instance sinter-based additive manufacturing and near-net-shape manufacturing by hot isostatic pressing.

Frank Adjei-Kyeremeh

Frank Adjei-Kyeremeh is a research assistant in the additive manufacturing group at the Foundry Institute of the RWTH Aachen University.

Jiali Zhang

Jiali Zhang is a postdoctoral researcher at the Institute for Materials Applications in Mechanical Engineering at RWTH Aachen University.

Iris Raffeis

Iris Raffeis is the head of the additive manufacturing group at the Foundry Institute of RWTH Aachen University.

Andreas Bührig-Polaczek

Andreas Bührig-Polaczek is the professor of the Foundry Institute at RWTH Aachen University.

Anke Kaletsch

Anke Kaletsch is the head of the division powder metallurgy and ceramics at the Institute for Materials Applications in Mechanical Engineering at RWTH Aachen University. She is also the deputy head of the Institute of Applied Powder Metallurgy and Ceramics (IAPK), which is an associated institute of RWTH Aachen University.

Christoph Broeckmann

Christoph Broeckmann is the professor of the Institute for Materials Applications in Mechanical Engineering at RWTH Aachen University.