Concept and Objectives:
In the project ADMAP-GAS new Unconventional Advanced Manufacturing Processes for Gas-Engine Turbine Components will be developed in order to substitute the critical conventional broaching process for fir tree profiles between rotating blades and disks. Therefore the two manufacturing technolgies “High Speed Wire-EDM Broaching” and “Abrasive Water Jet Broaching” – W² – will be developed, optimised and evaluated highlighting their individual performance and effectiveness for the machining task. High material removal rates and highest surface finishing will be achieved resulting in an equal or even better workpiece performance. By using these two unconventional manufacturing technologies with their inherent advantages a much higher technological and time based flexibility in production of fir tree profiles can be achieved. Failure risks and machining costs will be drastically decreased due to faster and more efficient machining in combination with a higher degree of automation. Tool wear and time consuming tool renewal can be avoided. Machine tool footprints (in comparison to conventional horizontal broaching centers) or machine heights and fundaments (vertical centers) will be drastically reduced. Energy consumption will be reduced and environment will be preserved. ADMAP-GAS addresses the relevance to the call by the “development of techniques for increased flexible tooling” for the manufacture of gas turbine components. The W² technologies will also enable the application of innovative and light weight design concepts (more complex shapes, tighter tolerances, etc.) for the turbine components that were not possible due to the technical limitations of the broaching process. This will additionally result in reduced production costs across the whole production cycles. Production waste and consumables will be minimised. A high degree of automation and faster machining times will result in a highly effective machining process with virtually no failure risk.
ADMAP-GAS Results in brief:
Flex tooling for gas turbine components
EU-funded scientists developed two alternative machining processes to broaching for the aeronautics industry. The advances offer improved cutting rates and decreased cost.
High market demand for gas-engine turbines in the aircraft industry has driven the need for more efficient, reliable and flexible manufacturing technologies for producing turbine components. The EU-funded project ‘Unconventional (advanced) manufacturing processes for gas-engine turbine components’ (ADMAP-GAS) developed two new, advanced systems in this respect. It focused on improved ways to manufacture ‘fir tree’ profiles that connect rotating blades and discs (blisks) in engines.
ADMAP-GAS evaluated abrasive water jet cutting (AWJC) and high-speed wire electrical discharge machining (HS-WEDM) to improve overall machining operations. No special tool had to be manufactured and tool wear had no influence on the workpiece performance. These new unconventional processes also helped to overcome machining challenges posed by the thermal and mechanical hardiness of nickel-based superalloys.
Scientists showed that both manufacturing technologies hold great promise for machining fir tree geometry profiles. Both processes improved material removal rates in combination with high form accuracy and surface quality. Compared to broaching, they allowed very flexible production of different profile geometries.
The developed AWJC process proved to be suitable for roughing cuts, which require a very economic technology to process hard-to-machine alloys. The process monitoring system, the multi-axis cutting head and the new developed nozzle geometry were all developed within ADMAP-GAS.
Furthermore, the HS-WEDM process also proved to be a serious alternative to broaching, especially in terms of surface fatigue behaviour. Through optimising technology, scientists improved cutting rates and achieved very good surface integrities (minimal surface layer and contamination, and absence of cracks).
Failure risks of engine discs decreased through the developed process monitoring systems. A life-cycle cost analysis showed a 25 % decrease in machining costs for producing a fir tree profile using one of the developed processes. Furthermore, both showed a large decrease in the environmental impact of machining processes, as much as 60 %, through reduced energy consumption.
Beyond the aeronautics industry, both technologies also offer much promise for the automotive industry.