59266 - Tolerance-Based Optimization of Sinking Edm for Industrial Seal-Slot Manufacture
Seal plates for turbine vanes significantly reduce gap losses and thus play a major role in increasing the efficiency of turbines. The industrial production of seal slots, which position the seal plates in the turbine vanes, is driven by the need for high productivity in combination with a reliable processing of necessary geometrical and surface integrity features. A machining technology that is able to machine hard-to-cut materials such as nickel based alloys is electrical discharge machining. Due to its electro-thermal working principle it is able to machine materials independently from their mechanical properties even at high aspect ratios. Achievable removal and wear rates as well as the resulting surface properties strongly depend on the discharge energy. Furthermore, the discharge energy affects the working gap sizes and therefore flushing efficiencies when machining high-aspect ratio cavities. This relationship is investigated taking into account various contemporary generator technologies and graphite grades from both, published literature and own experimental investigations. Their effect on machining performance focussing on productivity, white layer thickness and crack formation is quantified. Based on this data a novel empirical model for tolerance-based optimization is developed. The model is used to perform an optimization on an existing serial production and implementation has been proven successful.
Tolerance-Based Optimization of Sinking Edm for Industrial Seal-Slot Manufacture
Paper Type
Technical Paper Publication
Description
Session: 18-02 Subtractive Manufacturing
Paper Number: 59266
Start Time: June 9th, 2021, 09:45 AM
Presenting Author: Timm Petersen
Authors: Timm Petersen Laboratory for Machine Tools and Production Engineering (WZL) of RWTH Aachen University
Markus Zeis MTU Aero Engines AG
Thomas Bergs Laboratory for Machine Tools and Production Engineering (WZL) of RWTH Aachen University