Diffusion of Germanium in Binary and Multicomponent Nickel Alloys

Interdiffusion and impurity diffusion of Ge is studied in Ni and multicomponent alloys over the temperature range of 1150-1250 °C. The diffusion is investigated using diffusion couples, which are evaluated using microprobe measurements. The interdiffusion coefficients are calculated with the den Broeder method, while the impurity diffusion coefficients are determined with the Hall method. A model for the diffusion simulation software DICTRA is developed by mobility assessments. Further on, the diffusion of Ge in the multicomponent superalloys PWA1483 and René N5 is investigated. The Ge diffusion coefficient in René N5 is 4.5 × 10⁻¹⁴ m²/s at 1180 °C which is similar to other alloying elements such as Co, Cr, Mo or Ta.