Luminescence Piezo-spectroscopy for Lifetime Assessment and Improvement of Thermal Barrier Coatings

Completed

Energy Efficiency(Transport)
Other Power and Storage Technologies(Electric power conversion)
Fossil Fuels: Oil Gas and Coal(Oil and Gas, Oil and gas combustion)

Basic and strategic applied research

PHYSICAL SCIENCES AND MATHEMATICS (Metallurgy and Materials)
ENGINEERING AND TECHNOLOGY (Mechanical, Aeronautical and Manufacturing Engineering)

Not Cross-cutting

Professor A Atkinson
Materials
Imperial College London

Standard

EPSRC

01 April 2005

30 September 2008

42 months

£314,870

Materials processing

London

Metals Programme -- Materials, Mechanical and Medical Eng

Professor A Atkinson, Materials, Imperial College London

Professor K Nikbin, Department of Mechanical Engineering, Imperial College London

Project Contact, Turbine Surface Technologies Limited
Project Contact, Chromalloy UK Ltd
Project Contact, Alstom Power Ltd

Gas turbine engines rely on thermal barrier coatings (TBCs) on high pressure turbine blades to allow higher gas temperatures and achieve greater fuel efficiency and the integrity and lifetime of the TBC are crucial for future competitive performance. The overall aim of the project is to develop more reliable approaches to predicting the failure of TBCs on high pressure turbine blades and design improved TBC systems. This will be done by combining photo-luminescence piezo-spectroscopy, finite element mechanistic modelling and customised TBC fabrication methods. Piezospectroscopy is a non-destructive technique for monitoring the stress in the thermally grown aluminium oxide (TGO),that forms at high temperature in the coating. When the TGO is damaged locally, this can be seen in the spectroscopic signal. This is a powerful tool for monitoring the accumulation of damage and could form the basis of an NDE method for estimating residual life in service. The stresses that cause damage willbe estimated by the numerical modelling and then used to calculate the piezo-spectroscopic signatures of typical defects in order to validate interpretation of the spectra. The modelling approach will be extended to cover nucleation and growth of the damaged regions and how this depends on coating parameters. The customised TBCs will be used to isolate particular parameters (such as coating thickness and interface roughness) for investigation by piezospectroscopy in order to validate the model.Finally the understanding will be applied to develop methodology for the design of better coatings and give more accurate approaches to estimating their lifetime. The project will be carried out jointly by Imperial College and Cranfield University working in close collaboration with commercial producers and users of TBCs (Rolls-Royce, Chromalloy, Alstom and DSTL)

01/01/07