Modelling of microstructural evolution in multi-layered overlay coatings
journal contributionposted on 21.07.2017, 10:30 by Mudith Karunaratne, Mark JepsonMark Jepson, N.J. Simms, J.R. Nicholls, Rachel ThomsonRachel Thomson
Functionally graded, multi-layered coatings are designed to provide corrosion protection over a range of operating conditions typically found in industrial gas turbines. A model incorporating diffusion, equilibrium thermodynamics and oxidation has been developed to simulate the microstructural evolution within a multi-layered coating system. The phase and concentration profiles predicted by the model have been compared with an experimental multi-layered system containing an Al-rich outer layer, a Cr-enriched middle layer and an MCrAlYtype inner layer deposited on a superalloy substrate. The concentration distribution and many microstructural features observed experimentally can be predicted by the model. The model is expected to be useful for assessing the microstructural evolution of multilayer coated systems which can be potentially used on industrial gas turbine aerofoils.
This work was the supported by the Energy Programme, which is a Research Councils UK cross council initiative led by EPSRC and contributed to by ESRC, NERC, BBSRC and STFC, and specifically the Supergen initiative (Grants GR/S86334/01 and EP/F029748) and the following companies: Alstom Power Ltd., Corus, E.ON, National Physical Laboratory, QinetiQ, Rolls-Royce plc, RWE npower, Sermatech Ltd. and Siemens Industrial Turbomachinery Ltd.
- Aeronautical, Automotive, Chemical and Materials Engineering