ECM roughing of profiled grooves in nickel-based alloys for turbomachinery applications

Abstract

The connection of turbine blades and discs in turbomachinery is realized via profiled grooves. To manufacture these slots in turbine discs, made of hard to machine nickel-based alloys, broaching with high speed steel is state of the art. With improving materials, this process becomes less productive. Alternative manufacturing processes like electrochemical machining (ECM) have to be investigated with regard to their technical capability to fulfil the high requirements by the aerospace industry. Hence, in this paper the principle of ECM machining of profiled grooves in a nickel-based alloy with frontal gap flushing is outlined. A machining setup for a first experimental approach is designed, built and profiled grooves are machined. The grooves are measured with regard to the geometrical accuracy. The completion of the investigations is a comparison with other manufacturing processes in order to define an appropriate finishing process.