Optimisation of a Jewellery Platinum Alloy for Precision Casting: Evaluation of Mechanical, Microstructural and Optical Properties
[62, (4), 364 ]
An optimal platinum alloy for precision casting was developed by taking 25 possible alloying elements into consideration. In order to rank these elements an equation was designed. The ranking allowed five promising alloy compositions to be identified. From these five alloys arc melted buttons were produced and tested for homogeneity and hardness to ensure their suitability as jewellery alloys. A pyrometer was used to measure solidus temperatures. In a second iteration, the five alloys were further improved and the most promising alloys were cast and compared to a commonly used jewellery alloy: platinum-copper-gallium (PtCuGa). The comparison was based on the melting interval and on microstructural investigations, carried out by scanning electron and optical microscopy, while mechanical properties were determined by tensile testing. Additionally, optical properties such as reflectivity and colour were investigated. After the second iteration two very promising compositions were identified: PtCuFeMnCr and PtCuFePdVY.