Thermophysical properties of platinum-rich alloys measured by sessile drop experiments
Ulrich E. Klotz and Yuriy Plevachuk
mination of the melting range and measurements of the density as a function of temperature and composition of Pt-rich alloys (8 binary: PtRu1, PtRu3, PtRu5, PtCo1, PtCo3, PtCo5, PtCu5, PtAu5 and 6 ternary: PtCo1.5Ru3.5, PtCo3.5Ru1.5, PtCu1.5Ru3.5, PtCu3.5Ru1.5, PtAu1.5Ru3.5, PtAu3.5Ru1.5) were carried out by a sessile drop method. The contact angles between the alloys and the Al2O3 substrate at the liquidus temperature were determined. All specimens revealed a wide range of supercooling (up to 300°C), which enabled to investigate the alloys in the liquid state during cooling. The images were analysed using an edge detection algorithm based on the software ImageJ. The data of liquidus and solid temperatures were compared with the corresponding calculated values from thermodynamic simulations, the density values were compared with experimental data from literature.
Keywords: Platinum, density, melting range, investment casting, sessile drop