Multi-Criteria Assessment of Machining Processes for Turbine Disc Slotting

Abstract

Many different process chains are possible to manufacture profiled grooves in turbine discs. Broaching with high speed steel tools is still state of the art today but as a consequence of the rising demand for aero engines, the disc manufacturers are striving for alternative high performance processes to increase both flexibility and productivity in the manufacturing of these safety critical features. Broaching machines are oftentimes at a bottleneck in the production of rotating turbine discs. Several other machining processes have been discussed in the context of slotting, such as broaching with carbide tools, milling, water jet machining, W-EDM and grinding. Within this paper a multi-criteria assessment approach is presented dealing with slotting processes. The assessment comprehends economical, ecological, flexibility and productivity criteria, and is based on data gathered with an aero engine OEM. The technological aspects such as tool life and productivities are based on real machining tests that have been carried out within the project HoFePro. The assessment is conducted for multiple profile shapes that represent different sizes and geometrical complexities of profiled grooves. The manufacturing processes within the assessment include broaching with HSS and carbide, milling with ceramics and carbide (side and end) as well as profile milling with carbide tools. The underlying workpiece material is a nickel-based alloy.

Investigation of the Influence of Reduced Graphene Oxide Flakes in the Dielectric on Surface Characteristics and Material Removal Rate in EDM

“…One of the main nonconventional technologies that is widely used to manufacture conductive parts regardless of their hardness is electrical discharge machining (EDM). EDM has been widely used for the manufacturing of dies and molds and of aerospace parts [1,2,3,4]. The mechanism of material removal is the result of electrical discharge, which causes local melting and evaporation of a small volume of material.…”

Wire Electrochemical Machining with Pulsating Radial Electrolyte Supply and Preparation of Its Tube Electrode with Micro-Holes

“…Figure 8a shows a contour plot of the diameter, showing how the feed rate and the applied voltage influence the diameter. Figures 7b and 8b show the results corresponding to Figures 7a and 8a, but plotted using Equation (1). The left side of the yellow lines in Figures 7b and 8b are generated by equation, which cannot be acquired by experiments.…”

“…Then, we could find a reasonable parameter combine from the equation or the contour plot when drilling a specific diameter micro-hole. Figures 7a and 8a, but plotted using Equation (1). The left side of the yellow lines in Figures 7b and 8b are generated by equation, which cannot be acquired by experiments.…”

“…Low-cost precision machining presents a bottleneck when fabricating parts with ruled surfaces like the fir-tree slots in a turbine disc [1]. They are commonly made of difficult-to-cut materials such as nickel-based alloys and titanium alloys, and require strict surface integrity, allowing no recast layers nor microcracks.…”

Multi-Objective Parameter Optimization for Disc Milling Process of Titanium Alloy Blisk Channels

“…A current technique challenge was to calculate the tool orientation and locations (called plunger paths) in four-axis rough plunging of open blisks, so that the residual raw material left on the blades after roughing was closed to the specified value [11]. Klocke et al [12] presented a multi-criteria assessment approach to deal with turbine disc slotting process. Based on data gathered with an aero engine OEM, the assessment included economical, ecological, flexibility and productivity criteria.…”