As a follow-up to last year's presentation, this year's topic will go into more depth to introduce attendees to the metallurgical concepts underlying alloying behavior. After a brief review of the nature of metals and their characteristics (such as atomic and crystal structure, physical and chemical properties, etc.), the mechanisms of alloy formation will then be considered. This will include a discussion of the construction and interpretation of alloy phase diagrams with particular reference to alloy systems relevant to the jewellery and silverware industries. The properties of alloys, i.e., strength, hardness and ductility, can be influenced by heat treatment, and examples will be given as to how this can be achieved in certain carat gold and platinum alloys and in sterling silver. Finally, a brief summary will be given of the main classes of alloys used in jewellery manufacture and the effects of certain additives such as zinc, silicon and grain refiners on alloy properties.

Author: Mark Grimwade