Abstract
This work investigates the relationship between acoustic emission and chip segmentation frequency of Ti-6Al-4V at the external longitudinal turning process. Therefore, several sensors like structure borne sensors, microphones and a force dynamometer have been installed in a vertical turning machine. To induce a change of the segmentation frequency, several experiments with different feed rates have been carried out. From each experiment the acoustic emissions have been recorded and the generated chips have been analyzed. Since the chips get stretched or compressed during the chip formation the change in the length is calculated to get an estimation of the segmentation frequency. The comparison of the spectral analysis of the acoustic emission signals and the chip analysis has shown that both methods show the same tendency. The segmentation frequency decreases with increasing feed.
Zusammenfassung
In dieser Arbeit wird die Beziehung zwischen akustischer Emission und der Segmentspanbildungsfrequenz beim Außenlängsdrehen von Ti-6Al-4V untersucht. Dazu wurden in einer Vertikaldrehmaschine verschiedene Sensoren für Körperschall, Luftschall und eine Kraftmessplattform installiert. Um den Einfluss der Segmentspanbildungsfrequenz zu untersuchen, wurde bei den Experimenten der Vorschub variiert. Von jedem Experiment wurden die Schallemissionen aufgezeichnet und die dabei entstandenen Späne analysiert. Da die Späne während der Entstehung gedehnt bzw. komprimiert werden, wird die berechnete Längenänderung berücksichtigt, um eine Schätzung der Segmentspanbildungsfrequenz zu erhalten. Der Vergleich der Spektralanalyse der Schallemissionssignale und der Spananalyse zeigt, dass beide Methoden die gleiche Tendenz zeigen. Die Segmentierungsfrequenz nimmt mit zunehmendem Vorschub ab.
Dedicated to Fernando Puente León
Funding statement: The scientific work has been supported by the DFG within the research priority program SPP 2086 (ZA 785/3-1). The authors thank the DFG for this funding and intensive technical support.
About the authors
Daniel Schwär is research associate at the Institute of Industrial Information Technology at the Karlsruhe Institute of Technology. His current research interests in signal processing techniques and their application to acoustic emission at machining Titanium alloy.
Germán González studied mechanical engineering at the University of Oviedo and mechatronic engineering at the Karlsruhe University of Applied Sciences. After that he joined IDEKO research center where he worked on novel techniques for chatter suppression in machine tools. Since 2018, he works as research associate at the institute of production science (wbk) at the Karlsruhe Institute of Technology where he is pursuing research on process optimization to improve surface integrity of machined components.
After completion of an apprenticeship in metal forming, Eric Segebade studied Materials Science at the RWTH Aachen University, focusing on forming technologies and metal physics. Since 2015, he works on simulation based optimization of production processes at the institute of production science (wbk) at the Karlsruhe Institute of Technology.
Frederik Zanger holds the position as chief engineer of the research group ‘manufacturing and materials technology’ at wbk Institute of Production Science since 2012 and is currently heading the joint research group ‘Additive Manufacturing’ within the framework of an KIT-Industry Fellowship in cooperation with Rosswag Engineering. Furthermore he is responsible for the area of Mechanical Finishing at Edelstahl Rosswag. His research areas include machining, additive manufacturing and surface engineering.
Michael Heizmann is Professor of Mechatronic Measurement Systems at the Institute of Industrial Information Technology at the Karlsruhe Institute of Technology. His research areas include machine vision, image processing, image and information fusion, measurement technology, machine learning, artificial intelligence and their applications in industry.
Acknowledgment
The authors would like to thank Prof. Dr.-Ing. Fernando Puente León, who recently passed away unexpectedly, for his valuable support, and will always remember him.
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