This paper introduces the basic metallurgy of jewelry metals (gold, silver, platinum and palladium alloys) to those involved in the design and manufacture of jewelry. The variation of properties with alloy composition is shown in the context of the influence of alloying additions and the microstructure. The basis for this is explained in simple mechanistic terms. The effects of working and heat treatment on mechanical properties and the recovery of ductility by annealing are also explained in terms of changes to the alloy’s microstructure; how these can be influenced is also shown. The influence of minor alloying additions and impurities on structure and properties is discussed in terms of grain-size control and embrittlement. The importance of phase diagrams as a 'road map' to predicting microstructure and properties such as workability is explained. The basis of solders is also covered.

Author: Dr. Christopher W. Corti