While the market has been recognizing an increasing interest in 950 palladium jewelry, the development of Pd casting alloys and casting procedures for consistently high quality outcome has remained a real challenge for alloy suppliers and casting companies for some time. Among others this is related to some unique material properties of palladium compared to other jewelry components and the relative young history of investment casting Pd jewelry, which lead to a large spectrum of different casting process conditions favored by jewelry casters. The present paper first briefly reviews background information from literature, followed by a summary of the main results of a casting study sponsored by the Palladium Alliance International (PAI) and conducted at the German Research Institute for Precious Metals and Metal Chemistry (FEM). In the second part the paper reports on alloy development work at Legor: alloy design considerations and corresponding alloy properties, followed by results from casting trials at the Legor casting lab and manufacturing companies in the US. The paper is an update of the work already presented at the Santa Fe Symposium in 2007, which showed that consistently good quality casting of 950 Pd jewelry with reasonably high as-cast hardness and low susceptibility to cracking is possible with the combination of strict casting process control and optimized alloy composition.

Author(s): Dr. Jörg Fischer-Bühner,  Dr. Andrea Basso, Massimo Poliero