US 12,077,839 B1
Alloy with interference thin film and method for making the same
Wai Kei Cheung, Hong Kong (CN); Shuk Kwan Mak, Hong Kong (CN); and Candice Wing Jong Tong, Hong Kong (CN)
Assigned to CHOW SANG SANG JEWELLERY COMPANY LIMITED, Hong Kong (CN)
Filed by Chow Sang Sang Jewellery Company Limited, Hong Kong (CN)
Filed on Aug. 29, 2023, as Appl. No. 18/239,747.
Claims priority of application No. 32023076637.2 (HK), filed on Jul. 26, 2023.
Int. Cl. C22C 5/02 (2006.01); C22C 1/02 (2006.01); C22F 1/02 (2006.01); C22F 1/14 (2006.01); C23F 1/00 (2006.01)
CPC C22C 5/02 (2013.01) [C22C 1/02 (2013.01); C22F 1/02 (2013.01); C22F 1/14 (2013.01); C23F 1/00 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An alloy with an interference thin film, wherein:
i. said alloy consists essentially of 55.0-78.0 wt % Au, 8.0-24.0 wt % Ag, 8.0-24.0 wt % Cu and 0.0-3.0 wt % deoxidizer;
ii. said interference thin film is grown directly from within said alloy onto a surface of said alloy and has a thickness of less than 200 nm;
wherein said interference thin film exhibits a desired patination color.