Performance of precious metal alloys can be usefully compared by applying engineering design theory and heat-flow properties to small scale jewellery. The mechanical and physical properties of carat golds determine the possible processing routes and their limitations in manufacturing gold jewellery. Property data of some carat gold alloys are published, but seldom related to jewellery manufacture of through the application of engineering design principles. This paper describes such an approach and demonstrates how the alloy properties impact on some important processes used in the manufacture of gold jewellery. Examples include stone-setting, ring band design, chain-making, and localised heating for annealing or joining. This type of mechanical design approach requires a more analytical interpretation of alloy properties data than has been traditionally employed. The influence o f the alloy composition and cold-working on the limitations imposed on design and on processing is illustrated. New developments in quality controlled jewellery making, such as powder metallurgy, metal injection moulding and electro-forming are more likely to result from a technological approach than a traditional approach.

Authors: Dr. John C. Wright, Dr. Christopher Corti