Process for identifying Al alloys by electrochemical means
US4898646A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 2, 1989 |
| Grant date | Feb 6, 1990 |
| Priority date | — |
| Expiry date | May 2, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/4161
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
This invention relates to a process for identifying the external surface or surfaces of an Al alloy of a homogeneous or composite material by electrochemical means. This method involves forming an anodic layer, in situ, on the products to be identified, by electrolysis under predetermined conditions and following or plotting the development of the voltage U at the terminals of the electrolyzer as a function of time t during an intentiostatic test. The shape and relative position of curves U=f(t), thus obtained, allows the various alloys tested to be identified from a comparison of the derived curve from a curve U=f(t) derived from a known sample. The present method has advantages over the earlier methods of marking in that it provides: non-destructive method employable in situ on products which may have large dimensions (coils, plates, sheets, etc.); almost instantaneous identification; high reliability; and is simple and economic to use.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.