Dr. Joerg Fischer-Buehner - Legor Group S.p.A., Italy
Dr. Fischer-Buehner holds a diploma and a Ph.D. in physical metallurgy and materials technology from Technical University of Aachen, Germany. Since 2007 he has been active in research and development with Legor Group S.p.A., Italy, Indutherm GmbH, Germany, and BluePower Casting Systems GmbH, Germany. He was formerly head of the Physical Metallurgy and Precious Metals Research division of the Research Institute for Precious Metals & Metal Chemistry in Schwaebisch Gmuend, Germany. He is a recipient of the Santa Fe SymposiumÒ Research (two times), Ambassador, Outstanding Technical Presentation, Applied Engineering, and Collaborative Research (four times) Awards. This is his eleventh presentation at the Symposium.
A New 925 Silver Alloy with Increased Tarnish Resistance: From R&D through Real-Life Testing to Manufacturing
A new silver alloy has been developed with increased long-term tarnish resistance comparable to low-karat gold alloys and which requires no additional protective coatings. The paper reports on the alloy development, balancing hardness, manufacturing properties, tarnish resistance as well as metal costs (summarizing the results of an oral Santa Fe Symposium® presentation given in 2015). Results of accelerated lab tarnish tests are presented and compared with extensive real-life, long-term wear tests. Finally, examples of manufacturing trials from cooperating jewelry and watch manufacturers are presented, with a special focus on casting properties of the new silver alloy (silicon- and germanium-free) compared to regular sterling silver and fire scale-resistant alloys. The outcomes are discussed, keeping in mind consumer expectations and market approach.