Method of heat treatment of AL-based alloys containing Li and the product obtained by the method
US4897125A · kind A · utility
Inventors
Key dates
| Filing date | Oct 20, 1988 |
| Grant date | Jan 30, 1990 |
| Priority date | — |
| Expiry date | Oct 20, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22F1/04
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The invention concerns a method for final heat treatment tempering at Al alloys containing Li and at least one other major element selected from the group Cu, Mg and Zn, as well as possible minor elements such as Zr, Mn, Cr, Ni, Hf, Ti and Be, in addition to inevitable impurities such as Fe and Si. The treatment involves a principal tempering operation which takes place at a time and temperature in an area defined by a parallelogram on a temperature log-time diagram, whose corners have the following coordinates: (A) 270.degree. C.--3 min; (B) 270.degree. C.--48 min; (C) 225.degree. C.--9 hrs 30 min; (D) 225.degree. C.--35 min. The heat treatment makes it possible to produce a satisfactory array of mechanical characteristics such as mechanical strength, ductility, or toughness and resistance to corrosion, which are higher than those achieved by means of conventional treatments of type T6 or by under-ageing operations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.