Method and apparatus for generating microshells of refractory materials
US4670035A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 2, 1985 |
| Grant date | Jun 2, 1987 |
| Priority date | — |
| Expiry date | Jul 2, 2005 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03B19/10
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A system is described for forming accurately spherical and centered fluid-filled shells, especially of high melting temperature material. Material which is to form the shells is placed in a solid form in a container, and the material is rapidly heated to a molten temperature to avoid recrystallization and the possible generation of unwanted microbubbles in the melt. Immediately after the molten shells are formed, they drop through a drop tower whose upper end is heated along a distance of at least one foot to provide time for dissipation of surface waves on the shells while they cool to a highly viscous, or just above melting temperature so that the bubble within the shell will not rise and become off centered. The rest of the tower is cryogenically cooled to cool the shell to a solid state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.