Microstructure Analysis of Selected Platinum Alloys

Metallographic analysis can be used to determine the microstructure of platinum alloys in order to set up working cycles and to perform failure analyses. A range of platinum alloys used in jewellery and industrial applications was studied, including several commonly used jewellery alloys. Electrochemical etching was used to prepare samples for analysis using optical metallography and additional data could be obtained by scanning electron microscopy and energy dispersive spectroscopy. The crystallisation behaviour of as-cast alloy samples and the changes in microstructure after work hardening and annealing are described for the selected alloys.