This project aims at examining, understanding, and improving the mechanical properties of industrially used 18-carat gold alloys in a project supported by the Swiss CTI (Commission for Technology and Innovation) and Varinor, a manufacturer that refines and processes gold for the Swiss watch industry. Most of these alloys undergo an order-disorder transformation, which is critical for the ductility and hardness of the materials. Mechanical spectroscopy, provide a new way to investigate the crystal structure and the microstructure evolution as a function of thermo-mechanical treatments. The ordering mechanism is associated with a Zener peak characterizing the disordered state. Moreover, we investigate the casting process. The physical properties of different alloys are investigated and used for finite element simulation of the ingot microstructure and possible porosity.
Publications (2000-2009)
Hennig J, Mari D, Schaller R, Stress-induced and atomic ordering in 18-carat Au-Cu-Ag alloys. Materials Science and Engineering: A. 2009; 521-522, 47-51
