| Abstract Scope |
Ni-based alloys designed for high homologous temperature applications are among the most advanced metallic materials available. Their exceptional combination of high strength and excellent oxidation resistance makes them indispensable in aerospace, power generation, and nuclear industries. The long-term performance of Ni-based superalloys under harsh conditions is largely determined by the alloying elements, their concentrations, and the morphology of the primary strengthening phases. In this work the thermodynamic simulations of the Rene 125 microstructure were performed using ThermoCalc software with TCNi10 database. The scope of work included simulations of the solidification process using the Scheil model (no back diffusion) and analysis of phase stability under equilibrium conditions (presence of back diffusion). The thermodynamical predictions have been compared with the microstructure analysis carried out with scanning electron microscopy. According to the Scheil model, the following precipitates precipitate during crystallization in the Rene 125 superalloy: matrix, MC carbides, M5B3 borides, Ni7(Hf, Zr)2 intermetallic phase, and P phase. Based on the microstructure observations, the presence of secondary γ’ precipitates, MC carbides, M5B3 borides, and Ni7(Hf, Zr)2 intermetallic phase was confirmed.
The authors gratefully acknowledge the funding by the National Centre for Research and Development Poland under grant FENG.01.01-IP.01-000E/23. |