A alloy product containing Li, resistance to corrosion under stress, and process to obtain said product
US4955413A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 17, 1988 |
| Grant date | Sep 11, 1990 |
| Priority date | — |
| Expiry date | Feb 17, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22F1/053
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The invention concerns an Al alloy product containing lithium, with great specific mechanical strength and high tolerance to damage, particularly resistance to corrosion under stress in processed state (quenched-tempered), particularly in recrystallized state, and a process to obtain said product. The products according to the invention present a specific microstructure, with numerous rather coarse precipitates of intermetallic phases which are rich in Al, Cu, Li, Mg and optionally also Zn, of which the volume fraction is between 0.6 and 4%. A differential enthalpic analysis allows verification that the product has been processed according to the method which is claimed. This method consists of applying the following thermal treatments to the alloy: PA0 an optional heat maintenance stage in the course of the manufacture (for wrought alloys) or before placement in solution (for the cast alloys) at a temperature of between 490.degree. and 250.degree. C. for 1 to 48 hours. PA0 a placement in solution between 460.degree. C. and T.sub.M (.degree.C.) =474+18.2 (%2i) 2% Cu (%Cu-1.7)+% Mg (-17.6+3.6% Li +4.3% Cu)-3% Zn. The recrystallized products which are thus treated are not sensitive t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.