| 研究課題/領域番号 |
20K04192
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| 研究機関 | 京都大学 |
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研究代表者 |
ブカン アントニー 京都大学, 工学研究科, 特定准教授 (30756838)
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| 研究期間 (年度) |
2020-04-01 – 2023-03-31
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| キーワード | nano-abrasive blasting / super-fine finishing / particle agglomerates / material removal rate / surface roughness / acoustic streaming |
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| 研究実績の概要 |
In this second phase of research, the process characteristics of nano-blasting system were investigated. A prototype system consisting of high-pressure (2 MPa) air supply, Venturi effect nozzle, powder feeder, and the ultrasonic disintegration system developped in previous year, was assembled. The following was observed:
(1) Powder processed by ultrasound flowed more uniformly out of the nozzle. CFD simulations reveal that the powder, fed discontinuously from the screw-based feeder, becomes more evenly dispersed with air due to acoustic streaming in the cavity.
(2) Under identical process condition (same abrasive mass transfer and nozzle pressure), the ultrasound processed powder achieves 30% lower removal rate but a significantly improved surface roughness (up-to 3 time lower roughness Ra).
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
1: 当初の計画以上に進展している
理由
In accordance with the implementation plan (phase 2), homogenous mixing of abrasives with air inside the powder processing system was confirmed. The powder flows out of the nozzle substantially more uniformly when compared with the conventional system attached directly to a screw based powder micro-feeder. Using CFD simulations, the homogenous mixing was linked to acoustic streaming of the air circulating inside the cavity.
Thanks to the smooth progress of this phase, it was also possible to start work on the next phase by performing basic processing experiments on glass to assess the material removal rate and surface roughness. While material removal rate appears slightly lower (30%), surface roughness is significantly improved (3x) when compared with a conventional blasting system.
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| 今後の研究の推進方策 |
In accordance with the remaining contents of the implemtation plan (phase 3), the developped nano-blasting system will be used to process ductile material (metals) as well as the brittle material (glass) already tested. Again, the material removal rate and surface roughness will be used to quantify the acoutic assisted system performance.
As planned, the observed differences in material removal characteristics with conventional blasting systems will be simulated by smooth particle hydrodynamics (SPH) method. In particular, a model of aggregated particles based on Van der Waals energy potential will need to be developped in order to correctly model the respective behaviours of aggregated and disaggregated abrasive particles.
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| 次年度使用額が生じた理由 |
The purchased equipment in this fiscal year was slightly cheaper than expected, thanks to academic discounts.
The remaining amount (21,105円) will be used in next fiscal year to buy extra workpieces for the planned blasting process trials.
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