Properties of melt and thermal processes during solidification in jewellery casting

A survey is made of the significant thermal properties pertaining to liquid and solidifying jewellery alloys, and some properties of the investment are also considered. Values found in the literature, or measured in our own investigations are used together with estimates. A relatively simple model for solidification is presented. Some parameters such as volume/surface area ratio, superheat and solidification temperature are discussed. The solidification behaviour of a simplified ring is investigated in more detail using the model. In addition, some observations were made whilst casting spirals.