Investment casting brittle, reactive materials
US6024163A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 7, 1997 |
| Grant date | Feb 15, 2000 |
| Priority date | — |
| Expiry date | Jan 7, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB33Y80/00
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Investment casting shells, methods for their manufacture and methods for casting metals and alloys using such shells are disclosed. One feature of the shells is that the facecoat plus interior backup layers are purposefully designed to have substantially similar coefficients of thermal expansion to the seal dip layers. This helps reduce the occurrence of dimensional casting defects caused by differential thermal expansions of the layers comprising the shell. One embodiment of such a shell comprises a facecoat, plural interior backup layers and plural intermediate backup layers wherein at least one of the plural intermediate backup layers comprises a material capable of undergoing a volumetric transformation during cool down, and wherein the seal-dip layers have a coefficient of thermal expansion that varies from the coefficient of thermal expansion of the facecoat and interior backup layers by less than about 10 percent. A particular embodiment of the method is useful for investment casting aluminides, particularly TiAl, using a shell having an alumina facecoat.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.