Design techniques relating to the creation of Cadmium-free gold brazing alloys for jewelry fabrication applications are discussed with reference to Cadmium toxicity, substitute material performance characteristics and economic considerations. Attributes such as colour, thermal properties, physical properties, fluidity and mechanical processing techniques are evaluated to facilitate comparison of current Cadmium-based solders with the new non-toxic counterparts.

Results of research at Imperial Smelting and Refining indicate that rationalization of alloy design concurrent with the elimination of Cadmium, in favour of Indium or Tin, produces a series of alloys in 10, 14 and 18 karat white and yellow gold with equivalent or improved performance attributes. Increased alloy costs due to the higher intrinsic value of substitute metals can be offset by superior fabrication characteristics, reduced capital costs for smelting engineering controls and improved industrial hygiene conditions.

Author: Greg Normandeau