Method for preventing elution of Bi from copper alloy
US10000854B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 24, 2011 |
| Grant date | Jun 19, 2018 |
| Priority date | — |
| Expiry date | Nov 25, 2031 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE03B7/006
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Provided is a method for preventing the elution of Bi from copper alloy, in which the elution of Bi is prevented in leadless copper-alloy plumbing equipment and the like containing a trace of lead and a predetermined amount of Bi. The present invention relates to a method for preventing the elution of Bi from copper alloy in which at least Bi present on the surface of copper alloy containing Bi is selectively removed by preferentially dissolving Bi in a 4 to 20 mass % concentration of nitric acid while suppressing Cu dissolution. Furthermore, elution of Pb is suppressed using a 10-20 mass % concentration of nitric acid. In this case, by removing at least Bi present on the surface of copper alloy containing Bi using nitric acid and then treating the surface of the copper alloy by shot-blasting corrosive products, such as oxides, produced from the nitric acid are removed, and gloss is imparted to the surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.