Production of metal powders by gas atomization using swirl and non-swirl nozzles
Gas atomization, in which high-pressure gas jet impinges on molten metal stream from the melt tube to atomize it, is a popular method of producing fine metal powders. In this study, we focused on a swirling flow of the injection gas as a factor affecting the produced powder. Computational analyses a...
| Main Authors: | , |
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| Format: | Article |
| Language: | Japanese |
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The Japan Society of Mechanical Engineers
2022-06-01
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| Series: | Nihon Kikai Gakkai ronbunshu |
| Subjects: | |
| Online Access: | https://www.jstage.jst.go.jp/article/transjsme/88/910/88_22-00057/_pdf/-char/en |
| _version_ | 1817970406426935296 |
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| author | Kazuki YOSHIMURA Kazuya SAITO |
| author_facet | Kazuki YOSHIMURA Kazuya SAITO |
| author_sort | Kazuki YOSHIMURA |
| collection | DOAJ |
| description | Gas atomization, in which high-pressure gas jet impinges on molten metal stream from the melt tube to atomize it, is a popular method of producing fine metal powders. In this study, we focused on a swirling flow of the injection gas as a factor affecting the produced powder. Computational analyses and experiments were carried out to investigate the effect of the swirling gas flow on the atomization process. First, a single-phase flow analysis was performed considering only the injection gas. The simulated aspiration pressure agreed well with the experimental results. The behavior of the aspiration pressure against the gas injection pressure depended on the presence of the swirling flow. The simulation results clarified that the aspiration pressure was decreased by backflow into the melt tube in the case of the non-swirl nozzle. The backflow was caused by a vortex just below the melt tube tip, which was generated by the injected gas. On the other hand, in case of the swirl nozzle, the swirling flow decreased the pressure at the center of gas flow and inside the melt tube, which caused a high and stable aspiration pressure. Next, the effect of the swirling flow on the melt behavior and particle atomization was investigated numerically. A low-velocity region was generated at the center of the gas flow as a result of the mass loading of the melt, which was larger in the swirl nozzle. Consequently, the particles in the swirl nozzle were coarser than those in the non-swirl nozzle because some of the particles flying in the low-velocity region could not be atomized enough. Finally, metal powders were produced using a gas atomization plant, and the powder sizes and the surface images were compared. The powder size distribution showed that the non-swirl nozzle produced finer powders than the swirl nozzle did, as in the simulation results. |
| first_indexed | 2024-04-13T20:33:39Z |
| format | Article |
| id | doaj.art-df5b312d37614d28a99496f2afb4b1d3 |
| institution | Directory Open Access Journal |
| issn | 2187-9761 |
| language | Japanese |
| last_indexed | 2024-04-13T20:33:39Z |
| publishDate | 2022-06-01 |
| publisher | The Japan Society of Mechanical Engineers |
| record_format | Article |
| series | Nihon Kikai Gakkai ronbunshu |
| spelling | doaj.art-df5b312d37614d28a99496f2afb4b1d32022-12-22T02:31:06ZjpnThe Japan Society of Mechanical EngineersNihon Kikai Gakkai ronbunshu2187-97612022-06-018891022-0005722-0005710.1299/transjsme.22-00057transjsmeProduction of metal powders by gas atomization using swirl and non-swirl nozzlesKazuki YOSHIMURA0Kazuya SAITO1Hitachi, Ltd., Research and Development GroupHitachi Metals, Ltd., Yasugi WorksGas atomization, in which high-pressure gas jet impinges on molten metal stream from the melt tube to atomize it, is a popular method of producing fine metal powders. In this study, we focused on a swirling flow of the injection gas as a factor affecting the produced powder. Computational analyses and experiments were carried out to investigate the effect of the swirling gas flow on the atomization process. First, a single-phase flow analysis was performed considering only the injection gas. The simulated aspiration pressure agreed well with the experimental results. The behavior of the aspiration pressure against the gas injection pressure depended on the presence of the swirling flow. The simulation results clarified that the aspiration pressure was decreased by backflow into the melt tube in the case of the non-swirl nozzle. The backflow was caused by a vortex just below the melt tube tip, which was generated by the injected gas. On the other hand, in case of the swirl nozzle, the swirling flow decreased the pressure at the center of gas flow and inside the melt tube, which caused a high and stable aspiration pressure. Next, the effect of the swirling flow on the melt behavior and particle atomization was investigated numerically. A low-velocity region was generated at the center of the gas flow as a result of the mass loading of the melt, which was larger in the swirl nozzle. Consequently, the particles in the swirl nozzle were coarser than those in the non-swirl nozzle because some of the particles flying in the low-velocity region could not be atomized enough. Finally, metal powders were produced using a gas atomization plant, and the powder sizes and the surface images were compared. The powder size distribution showed that the non-swirl nozzle produced finer powders than the swirl nozzle did, as in the simulation results.https://www.jstage.jst.go.jp/article/transjsme/88/910/88_22-00057/_pdf/-char/engas-liquid two-phase flownumerical simulationatomizationswirling flowmetal powderadditive manufacturing |
| spellingShingle | Kazuki YOSHIMURA Kazuya SAITO Production of metal powders by gas atomization using swirl and non-swirl nozzles Nihon Kikai Gakkai ronbunshu gas-liquid two-phase flow numerical simulation atomization swirling flow metal powder additive manufacturing |
| title | Production of metal powders by gas atomization using swirl and non-swirl nozzles |
| title_full | Production of metal powders by gas atomization using swirl and non-swirl nozzles |
| title_fullStr | Production of metal powders by gas atomization using swirl and non-swirl nozzles |
| title_full_unstemmed | Production of metal powders by gas atomization using swirl and non-swirl nozzles |
| title_short | Production of metal powders by gas atomization using swirl and non-swirl nozzles |
| title_sort | production of metal powders by gas atomization using swirl and non swirl nozzles |
| topic | gas-liquid two-phase flow numerical simulation atomization swirling flow metal powder additive manufacturing |
| url | https://www.jstage.jst.go.jp/article/transjsme/88/910/88_22-00057/_pdf/-char/en |
| work_keys_str_mv | AT kazukiyoshimura productionofmetalpowdersbygasatomizationusingswirlandnonswirlnozzles AT kazuyasaito productionofmetalpowdersbygasatomizationusingswirlandnonswirlnozzles |