High-speed fabrication of highly uniform metallic microspheres
US6562099B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 18, 2001 |
| Grant date | May 13, 2003 |
| Priority date | — |
| Expiry date | May 18, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K3/3478
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
In a high-speed fabrication process for producing highly uniform metallic microspheres, a molten metal is passed through a small orifice, producing a stream of molten metal therefrom. A series of molten metal droplets forms from the break up of the capillary stream. To achieve high uniformity of the spheres and avoid defects, the droplets are cooled before being captured. Separating the droplets, by causing them to travel in different paths than their adjacent droplets, helps to facilitate the cooling of the droplets. The droplets can be separated by electrostatically charging them as they break off from the capillary stream. The droplets are then passed through an electric field, which can be produced by a pair of deflection plates. The droplets are dispersed by varying the electric field—e.g., by rotating the plates or by varying the voltage applied thereto—or by varying the electrostatic charge of the droplets. Advantageously, the droplets can be actively cooled in flight by passing them through a cryogenic gas chamber.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.