processes for cutting
processes for cutting edge rounding or chamfering include dry and wet abrasive waterjet, brushing, drag finishing, magneto abrasive machining and laser machining [13, 14] , as shown in figure 3. Abrasive jet machining Brushing Drag finishing Surface functionalization by means of microstructures In terms of tool wear mechanisms, adhesion is quite promi - nent in machining ductile materials like some low-carbon mild steels, aluminum and titanium alloys. Material adhesion is generally associated with built-up edges and built-up layers, which interfere with the cutting process in a way that the effective cutting edge geometry is changed and hence the surface integrity of the workpiece deteriorates. Magneto abrasive machining Abrasive flow machining Measures to alleviate adhesion comprise low friction coating systems, use of lubrication and the functionalization of tool faces by means of micro structures. The first two aspects are already state of the art, the latter aspect of micro structured tools is still under research. Grinding Electrical discharge machining Laser machining figure 3 Methods for cutting edge preparation [13] With laser technology, advantages concerning precision and reproducibility can be combined. Ultra-short pulsed (USP) lasers allow a virtually athermal processing with almost no thermal conductivity. On the other hand, the thermal impact can be used to alloy or disperse the fringe of HSS-tools by short-term melting. In terms of edge preparation, laser process can be used to constitute a purpose specific edge geometry in a multitude of cutting materials [15] . The non-contact nature of laser material interaction also means advantageous wear free processing and hence high reproducibility in industrial series production. To this day, conventional cutting preparation techniques still prevail. With the continuing understanding of laser-material interaction and better process guidance, the application of laser in respect of edge preparation may soon offer a viable technological alternative. USP laser systems achieve the implementation of defined nano- and microscale structures on the tool surface with very high precision and least thermal impact. In academia micro structured tool faces are investigated in a variety of processes. Research activities indicate promising potential in reducing process forces and adhesion combined with benefits of longer tool life and better quality performance [16, 17, 18] . Lower cutting forces and less adhesion are confirmedly explained by better tribological characteristics and less friction [19] . The microstructures in question are in most cases defined technical geometries like dots or line-like pitches as given exemplary in figure 4. The surface preparation contributes to less contact between chip and tool, higher shear angles and higher lubrication effectiveness [16, 20] . The cavities function as a reservoir and supply lubrication under concealed conditions when the cutting tool is engaged [17, 21] . Some researchers also consider bio-inspired surface designs in order to achieve higher anti-adhesion features and better lubrication distribution. The transformation from prototype status and laboratory conditions onto production tool has yet to be implemented in any case. Still, legitimate questions on real tool performance behavior and tool life have to be addressed. figure 4: Miroscopic images of tools with different rake face structuring [19] 30 no. 2, June 2020
processes Conclusion The performance requirements in modern machining processes demand for new cutting materials but also affect the production process. The progressive understanding of toolmaterial interaction, wear mechanisms and working material behavior create new approaches in tool optimization. The cutting tool micro geometry, pre- and post-treatment steps but also new high-strength cutting materials come in focus, raising the questions of how to process and realize the features. Laser technology has greatly evolved in recent years and new applications arose in many technical fields. With respect to cutting tool manufacturing, laser application delivers the access to further possibilities. With new USP laser systems high efficiency on the one hand and high precision processing on the other can be achieved. As this article stated, the application of laser is suitable in macro working of cutting tools as an alternative or logical addition to grinding but also in the field of micro working to precisely define cutting edge conditions or micro structured surfaces. Literature [1] Friemuth, T. (2002): Herstellung spanender Werkzeuge. Postdoctoral thesis. in: Fortschrittberichte VDI: Reihe 2, Betriebstechnik 615 (2002) [2] Klocke, F.; König, W. (2007): Fertigungsverfahren 1. Drehen, Fräsen, Bohren 8., neu überarbeitete Auflage [3] Denkena, B.; Köhler, J.; Rehe, M. (2010): Einsatz hochharter Schneidstoffe beim Schleifen in: Wissenschaft und Forschung 3 (2010), page 26-32. accessible: https://d-nb.info/1006343032/34 [4] Körber Schleifring GmbH (2011): Effektiv lasern und schleifen accessible: https://⁄ [5] Ewag AG (2017): Werkzeugbearbeitung via Laser: Ultrakurzpuls-Technologie meistert schwierigste Aufgaben beim Werkzeugschleifen accessible: https://mav.industrie.de/fertigung/ maschinen/werkzeugbearbeitung-via-laser/ [6] Kötter, D. (2006): Herstellung von Schneidkantenverrundungen und deren Einfluss auf das Einsatzverhalten von Zerspanwerkzeugen, Doctoral thesis [7] Pulsar Photonics GmbH (n.d.): Bearbeitung von Technischer Keramik mittels Ultrakurzpuls Laserstrahlung accessible: https://www.pulsar-photonics.de/ bearbeitung-von-technischer-keramik/ [8] Marcatis Laserbearbeitung (2019): Mikrolasergravur von Spanleitstufen und Spanbrechern bei MARCATIS accessible: https://www.marcatis.de/mikrolasergravur-vonspanleitstufen-und-spanbrechern-bei-marcatis/ [9] Biermann, D. (2012): Spanende Fertigung: Prozesse, Innovationen, Werkstoffe 6. Ausgabe, Essen: Vulkan-Verlag [10] Tikal, F.; Bienemann, R. (Hrsg.) (2009): Schneidkantenpräparation: Ziele, Verfahren und Messmethoden; Berichte aus Industrie und Forschung Kassel: Kassel Univ. Press [11] Denkena, B.; Köhler, J.; Mengesha, M. S. (2012): Influence of the cutting edge rounding on the chip formation process: Part 1. Investigation of material flow, process forces, and cutting temperature In: Production Engineering 6 (4-5), page 329-338 [12] Denkena, B.; Boehnke, D.; Leon-Garcia, L. (2005): Einfluss der Schneidkantengeometrie auf die Zerspankräfte und auf das Verschleißverhalten in: ZWF 100 (9), page 490-494 [13] Denkena, B.; Biermann, D. (2014): Cutting edge geometries in: CIRP Annals - Manufacturing Technology 63 (2), page 631-653 [14] Heisel, U. (2014): Handbuch Spanen 2., vollst. neu bearb. Aufl., München: Hanser. [15] Haferkamp, H; Bunte, J; Becker, H; Deutschmann, M. (2004): Lokale lasergestützte Verschleißreduzierung bei spanenden Schaftwerkzeugen in Verbindung mit Multilayer-Dünnschichten Forschungsbericht P 521 [16] Zhang, K.; Deng, J.; Sun, J.; Jiang, C.; Liu, Y.; Chen, S. (2015): Effect of micro/nano-scale textures on anti-adhesive wear properties of WC/Co-based TiAlN coated tools in AISI 316 austenitic stainless steel cutting in: Applied Surface Science 355, page 602-614 [17] Arulkirubakaran, D.; Senthilkumar, V.; Kumawat, V. (2016): Effect of micro-textured tools on machining of Ti-6Al-4V alloy: An experimental and numerical approach in: International Journal of Refractory Metals and Hard Materials 54, page 165-177 [18] Enomoto, T; Sugihara, T. (2010): Improving anti-adhesive properties of cutting tool surfaces by nano-/micro-textures in: CIRP Annals - Manufacturing Technology 59 (1), page 597-600 [19] Kawasegi, N.; Sugimori, H.; Morimoto, H.; Morita, N.; Hori, I. (2009): Development of cutting tools with microscale and nanoscale textures to improve frictional behavior in: Precision Engineering 33 (3), page 248-254 [20] Enomoto, T; Sugihara, T. (2011): Improvement of anti-adhesive properties of cutting tool by nano-/micro-textures and its mechanism in: Procedia Engineering 19, page 100-105 [21] Sharma, V.; Pandey, P. M. (2016): Recent advances in turning with textured cutting tools: A review in: Journal of Cleaner Production 137, page 701-715 further information: www.ipa.fraunhofer.de no. 2, June 2020 31
