The basic metallurgy of Sterling Silver with copper as the alloying element is discussed and the typical microstructural features are explained from the classical non-equilibrium solidification model. Quantification of copper segregation is also derived from the model. Precipitation hardening and annealing behavior are described with practical processing tips.

Replacement of all or some of the copper by other elements has been studied throughout at least the last 60 years. Alternate Sterling compositions have been designed for specific purposes, such as investment casting, reduced fire staining or improved tarnish behavior. This paper provides a basic understanding of some of the alternate compositions andthe effects of element additions such as Zn, Ge, Si, etc. on Sterling characteristics.

Author: Aldo M. Reti