Ermüdungsfestigkeit drahtfunkenerodierter Nickelbasiswerkstoffe für Triebwerksanwendungen; 1. Auflage

The improvement of thermal efficiency in aircraft engines to enhance overall performance is accompanied by increasing demands on the dynamic strength design of engine components made from materials such as the nickel-based alloy IN718. Consequently, the expanding aerospace sector requires alternatives to established manufacturing routes. The wire electrical discharge machining (WEDM) process, based on the principle of material removal via electrical discharges, is particularly suitable for producing high-precision geometries in demanding materials, such as the manufacture of profile grooves in turbine disks. However, the technological development of a certified manufacturing process involves time- and cost-intensive iterations. The present work addresses this issue with the aim of systematically developing the specifics of WEDM for a knowledge-based, strength-oriented technology design and investigating its correlation with the dynamic component strength based on signal characteristics. Initially, the fundamental individual energetic events of the process – the individual discharges – were examined, the influences on the removal characteristics were described, and different types of discharges were differentiated. Subsequently, several variants of a multi-cut technology were characterized using spatially resolved offline and online process analysis and energetically compared based on derived specific characteristic values. The previously determined fundamental data formed the basis for the generation of the characteristic values. Finally, fatigue tests were conducted to determine the dynamic strength of the WEDM technology variants, a grinding process, as well as process chains of the WEDM or grinding process combined with additional post-processing. Depending on process design, WEDM achieved either higher or lower fatigue strengths compared to grinding, which could be further enhanced through the application of post-processing methods. The previously extracted spatially resolved process parameters enabled extensive insights into the underlying relationship between process design and dynamic strength, particularly elucidating the effects of the inherently inhomogeneous gap condition of WEDM processes.