Abstract
The attractive color of blue and especially purple gold alloys has always intrigued jewelry designers and producers. The reality of using these colors for jewelry has been very limited, however, mainly due to the inherent brittleness and poor corrosion resistance of this special class of gold alloys. The paper reports on some improvements in crack resistance that are obtained by particular additions to 14k blue- and 18k purple-gold colored alloys. Opportunities to incorporate such colors in jewelry design with these modified, colored-gold alloys using investment casting (as well as the still existing limitations) are discussed. Special attention is given to bi-metal casting technologies that can be used to manufacture multi-colored jewelry. A protective, transparent and wear-resistant coating finally needs to be applied to minimize corrosion and improve long-term stability of the colorful pieces.
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Dr.-Ing. Jörg Fischer-Büuhner holds a PhD in Physical Metallurgy and Materials Technology of the technical university RWTH Aachen, Germany. He is actually active in Research & Development for LegorGroup Srl (Bressanvido, Italy) as well as Indutherm Erwärmungsanlagen GmbH (Walzbachtal, Germany). Before he was Head of Division of Physical Metallurgy at FEM, Research Institute for Precious Metals and Metal Chemistry (Schwäbisch Gmünd, Germany).
Dr Andrea Basso is the R&D and technical manager of LegorGroup Srl in Italy. He has acquired experience on process engineering and research in the chemical industry for more than 10 years. Since 2000 he started to work at Legor on the manufacturing process development and since 2001 he has been in charge of the development of the research and development activities.
Massimo Poliero is the Managing Director of LegorGroup Srl. He holds a diploma in metallurgy and has acquired a direct and wide experience on the jewelry manufacturing technology as a technical director in several important jewelry companies of the Vicenza district. In 1992 he became the technical director of Legor snc and since 1995 he has been the managing director.
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Fischer-Bühner, J., Basso, A. & Poliero, M. Metallurgy and processing of coloured gold intermetallics — Part II: Investment casting and related alloy design. Gold Bull 43, 11–20 (2010). https://doi.org/10.1007/BF03214962
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DOI: https://doi.org/10.1007/BF03214962