Method for fabricating superplastically formed/diffusion bonded structures
US4220276A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 25, 1978 |
| Grant date | Sep 2, 1980 |
| Priority date | — |
| Expiry date | Aug 25, 1998 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12806
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method for fabricating superplastically formed/diffusion bonded structures wherein metal blanks of a titanium alloy are joined at selected areas by diffusion bonding and expanded superplastically to form a desired sandwich or integrally stiffened structure. In such method, the metal blanks are treated in selected areas with a "stopoff" material to prevent bonding at those areas during diffusion bonding and to permit forming or shaping at the same areas during superplastic forming. An improved stopoff compound is provided for this purpose, in the form of yttria of relatively coarse particle size, coarser than 5 microns, in a suitable volatilizable vehicle. Such stopoff compound is inert to reactive metals such as titanium at the high diffusion bonding temperatures, and permits relatively low breakthrough pressure-time product during superplastic forming, thereby preventing excessive strain or rupture of the metal through non-superplastic deformation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.