Gold diffusion process and shaped metal articles thereby
US3953246A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 14, 1974 |
| Grant date | Apr 27, 1976 |
| Priority date | — |
| Expiry date | Nov 14, 1994 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12903
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
An improved gold diffusion coated shaped copper alloy article is provided by forming a copper alloy with chemical composition in the range 1 to 10% of aluminum and/or 0 to 10% of tin and optionally from 0 to 5% of free machining additives such as lead, selenium, tellurium, silicon, or others, remainder copper, into a desired shape and heating the shaped article to a temperature of from 700.degree.C to 900.degree.C and thereafter quenching the article at a controlled rate either in a gas or liquid quenchant. The shaped and hardened article is then galvanically coated with a layer of gold or gold alloy from 1 to 5 microns thick, and the gold coating diffused into the hardened copper alloy body by heating at a temperature from 400.degree.C to 900.degree.C for from less than one minute to 30 minutes, thereby diffusing the gold into the hardened base copper alloy. The process is particularly useful in forming watch bezels. The heating and quenching of the shaped copper alloy article forms a fine-grained eutectoid duplex two phase structure which is believed to enhance the rate and depth of diffusion and evenness of penetration of the gold layer. Gold coated hardened copper alloy article…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.