| About this Abstract |
| Meeting |
MS&T21: Materials Science & Technology
|
| Symposium
|
Computation Assisted Materials Development for Improved Corrosion Resistance
|
| Presentation Title |
Modelling Microstructural Evolution of Aluminide Coatings on Ni-based Superalloys |
| Author(s) |
Wencai Leng, Dmitry Naumenko, Rishi Radhakrishnan Pillai |
| On-Site Speaker (Planned) |
Wencai Leng |
| Abstract Scope |
Aluminide coatings enhance the oxidation resistance of Ni-based alloys used in aero-engine and power-generating gas turbines. The degradation of aluminized Ni-based superalloys was investigated during cyclic oxidation in air at temperatures of 950 - 1100 °C. A thorough analysis of the coating microstructures in the as-manufactured condition and after thermal cycling was performed using SEM / EDX / WDX / EBSD. A coupled thermodynamic-kinetic model was used to predict the coating microstructural changes simultaneously considering oxidation and interdiffusion processes. Excellent agreement was observed between experimental and modelling results, which correctly predicted transformation of NiAl into Ni3Al and γ-Ni, overall Al-depletion, and precipitation and dissolution of TCP phases, carbides and borides in the coating. The composition of the substrate alloy was found to have a major impact on the coating systems by influencing not only Al loss due to interdiffusion but, after long exposure time, also the oxidation behavior. |