Session: 18-08 Advanced Manufacturing and Design II

Paper Number: 123636

123636 - Tool Wear Prediction in Broaching Based on Tool Geometry 

Due to its central function, the engine of an aircraft is a safety-critical assembly. Constructive modifications resulting in ecological and economic improvements of the operating turbine led to changes in the manufacturing processes. The turbine discs in the low-pressure section are made of temperature resistant nickel-based superalloys. For the connection of the turbine blades with the disc, fir tree slots are manufactured in broaching. The broaching process achieves highest geometrical accuracy as well as process reliable rim zone properties.

Especially in finishing operations, the tool geometry is complex, so that in current research work, first the local rake angle and, as a result, the acting cutting forces were determined analytically. Based on these findings, the relationship between tool geometry and cutting force and tool wear will be investigated in this work to enable a cutting length dependent prediction of tool wear. The aim of the investigation is a model-based prediction of tool wear for a given cutting length at a previously unknown. For this purpose, the tool and process parameters rake angle, clearance angle, cutting speed and chip thickness are varied and the wear during the machining of Inconel 718 DA is empirically investigated by means of analogy tests. Chip formation simulations were also carried out to improve the understanding of the process. The results of the investigation are statements about the relationships between the varied parameters and the tool wear, which can be transferred into an empirical-analytical model.

With the results of this work, it is not only possible to identify critical points on newly developed broaching tools by maxima in the force, as was previously the case, but also to predict the wear locally, depending on the cutting length. As a result, component-specific tools can be optimized, and the efficiency of the broaching process can be increased.

Presenting Author: Christoph Zachert Werkzeugmaschinenlabor WZL Der RWTH Aachen

Presenting Author Biography: Christoph Zachert is a research associate at the Laboratory for Machine Tools and Production Engineering WZL at RWTH Aachen University. After his studies at RWTH Aachen University and a trainee position at Premium Aerotech GmbH, he has been conducting research in the field of machining technology since November 2020. His scientific focus is the broaching manufacturing process, which is used for grooving turbine disks in the aerospace sector.

Authors:

Christoph Zachert Werkzeugmaschinenlabor WZL Der RWTH Aachen
Markus Meurer Werkzeugmaschinenlabor WZL der RWTH Aachen
Thomas Bergs Werkzeugmaschinenlabor WZL der RWTH Aachen