The Role of Grain Size in the Jewelry Alloy
Chris Corti manages his own consultancy business COReGold. A small consultancy centred on precious metals science and technology, and its applications in industry and particularly in the jewelry sector
What is the importance of grain size in a jewelry alloy? The grain (crystal) size is important in jewelry because it can influ- ence the mechanical properties and physical appearance of the jewelry. We desire a small (fine) grain size to optimise the mechani- cal properties and to make manufacturing easier. A large grain size can lead to poorer strength, ductility, enhance embrittlement and tendency to crack. The surface will also appear rougher (“orange peel” appearance).
Are there any differences between alloys and their grains? Some of them tend to have larger (coarser) grains, but it’s the casting and the mechanical processing of the alloys that have the major effect.
How do the jewelry companies control the provenance and the quality of the grains? It is done by careful control of alloy composition and the subsequent processing of the alloy to finished jewelry. This requires metallurgical expertise.
What are the main criticalities when working with low quality grains? It is not a question of low quality but control of grain size. Low quality is only important in the context of deleterious impurities in the alloy composition that may, for example, cause embrittlement of the alloy. Too much silicon addition will cause embrittlement for example.
What would you suggest the companies should do to prevent any troubles? It is all down to metallurgical knowledge and careful control of casting and subsequent mechanical processing.
How should the companies approach the innovation to be more competitive? Technical innovation and design innovation is crucial to success in the jewelry market. Technical innovation helps to lower production costs, speeds up getting new products to the market place and enables bigger design opportunities to create more desirable jewelry.
Are there any differences between alloys and their grains? Some of them tend to have larger (coarser) grains, but it’s the casting and the mechanical processing of the alloys that have the major effect.
How do the jewelry companies control the provenance and the quality of the grains? It is done by careful control of alloy composition and the subsequent processing of the alloy to finished jewelry. This requires metallurgical expertise.
What are the main criticalities when working with low quality grains? It is not a question of low quality but control of grain size. Low quality is only important in the context of deleterious impurities in the alloy composition that may, for example, cause embrittlement of the alloy. Too much silicon addition will cause embrittlement for example.
What would you suggest the companies should do to prevent any troubles? It is all down to metallurgical knowledge and careful control of casting and subsequent mechanical processing.
How should the companies approach the innovation to be more competitive? Technical innovation and design innovation is crucial to success in the jewelry market. Technical innovation helps to lower production costs, speeds up getting new products to the market place and enables bigger design opportunities to create more desirable jewelry.
