Practical experience shows that gold alloy castings with homogeneous composition (and fineness) can only be obtained if some specific rules are respected. When the producer does not utilize the best practices for the preparation of the material, non-homogeneous castings could be obtained resulting in jewelry pieces that do not comply with the claimed fineness. In this work, we considered the homogeneity of the castings (obtained by means of investment casting or ingot casting) that were produced using different practices, i.e. with or without a pre-melting operation. The experiments were carried out with alloys of different fineness and color. Our experiments showed that pre-melting guarantees a better composition homogeneity in all parts of a casting.

Author: Dr. Alessandro Zocca, Dr. Daniele Maggian, Dr. Silvano Bortolamei,  Paolo Baretta, Dr. Andrea Trentin, Cemil Dogan