In 2011, a joint core removal research programme was instigated between Rolls-Royce, LBBC Technologies and the University of Birmingham to study the fundamental Physics and Chemistry of the Core Removal Process. Having now been undertaking this study for 1 year it is requested to present a paper with some of this research and the practical trials/case studies that have also been performed. By way of background, during operation gas turbine engine components are often exposed to extreme temperatures and pressures. Internal passageways through which cooling air is passed helps the components to survive in these harsh conditions. The cooling channels are formed via the placement of a ceramic core within a mould during the investment casting process. Once cast the core must then be removed. This has been achieved using a utilising a pressure swing system/autoclave. The current project focuses on understanding the physics and chemistry of the core removal process to enhance its industrial application. The paper will describe:

• The equipment used to facilitate the removal of cores. • The chemistry of the reagents used. • The physics behind the process. Rolls-Royce PLC is a global company, providing integrated power solutions for customers in civil and defence aerospace, marine and energy markets. LBBC Technologies have supplied over 50 core leaching autoclave systems over the last 25 years and have worked with the leading engine manufacturers throughout the world. A previous paper on the general principle of the autoclave core leaching process was presented by Howard Pickard, LBBC Technologies at the ICI show in 2011.