Objectives

• To optimise and standardise the measurement of ductile brittle transition temperature and thermo-mechanical fatigue of corrosion resistant coatings
• To provide guidance to industry on the lifetime limiting factors affecting thermal barrier coatings in gas turbines

Introduction

Many high temperature components are now coated before entry into service to protect them from corrosion and to increase the maximum service temperature. There are generic issues regarding the performance of corrosion resistant coatings, particularly the definition and measurement of ductile brittle transition temperature (DBTT) and the determination of thermo-mechanical fatigue (TMF) behaviour. Test methods for these properties exist but there is a requirement to optimise and standardise them. There are also concerns that apply specifically to thermal barrier coatings (TBCs) in gas turbines. Gas turbines provide a low emission solution to power generation. Increased use of this technology will result in a reduction in CO₂ and NO_x emissions and thus help the UK to achieve the targets set under the Kyoto protocol.