A high temperature coating integrated with a high performance heat exchanger for turbine blade tip cooling

"Turbine blade tip failure is one of the most critical issues facing future development of gas turbine engines. This proposal describes an inexpensive method to deposit a highly effective micro heat exchanger made from a MCrAlY alloy on the tip of ablade. The combination of the very efffectively cooled tip and the excellent mechanical and oxidation resistant properties of MCrAlY alloys will allow the tip to better survive the harsh environment associated with the hot gas path of gas turbines. Theprocess involves using the LIGA micromachining process to mass-produce disposable silicone masks that can be easily applied to a surface of interest. Proprietary electrodeposition techniques at PraxAir are then used to electroplate the M+CrAlY heatexchanger through the mask. After deposition, a heat treatment results in the desired MCrAlY properties, while the masking process provides the desired geometry associated with the intricate micro heat exchanger. The focus on improved tip, blade, and vane design to reduce associated heat load will lead to reduced coolant usage and thus provide higher overall efficiency. The mechanical integrity, life, efficiency, vibration, heat transfer, aerodynamic performance,and noise are all greatly influenced by the tip clearance. The trend towards higher loading, higher temperature, and lower aspect ratio intensifies the importance of the tip clearance effects to the turbine designer. The proposed te