High-pressure flank cooling and chip morphology in turning Alloy 718Show others and affiliations
2021 (English)In: CIRP - Journal of Manufacturing Science and Technology, ISSN 1755-5817, E-ISSN 1878-0016, Vol. 35, p. 659-674Article in journal (Refereed) Published
Abstract [en]
The use of cutting fluids is commonly considered a necessity while machining Heat Resistant Super Alloys (HRSA). Specifically, cutting fluids applied under high-pressure, which for many decades have been the solution for the most demanding applications. The results might be diverse and vary between applications, but typically leads to improved tool life, enhanced chip breakability, lower temperature in the cutting zone and better surface quality of the finished product. The available high-pressure cutting fluid delivery systems are usually designed with the intention to improve the cutting fluid penetration at the vicinity of the cutting edge on the rake face side of the insert. However, there has been limited interest in investigating high-pressure cutting fluid applied to its flank face. Both specifically and in combination with cutting fluid directed to the rake face. In this study, the focus has been to investigate the chip formation process during the turning of Alloy 718 (Inconel 718). Particularly, for a defined turning operation where high-pressure cutting fluid is applied to the flank side as well as the rake side of an uncoated carbide insert. Several combinations of pressure levels and jet directions were investigated. The corresponding effects on the tool-chip contact zone and chip characteristics were studied for two cutting speeds. The results of the investigation showed a substantial improvement in lowering the tool-chip contact area at a rake pressure of 16 MPa. At which pressure, additional cutting fluid applied to the flank at a moderate pressure of 8 MPa had no dominant effect on chip formation (chip break). However, flank cooling of the cutting zone supports chip segmentation and thus indirectly chip breakability. For cutting fluid applied to the rake side at a more moderate pressure of 8 MPa, more prominent effects on the insert became apparent when additional cutting fluid was applied to the flank side. This was particularly noticeable when cutting fluid was directed towards the flank side of the insert at the same pressure level as the cutting fluid applied towards its rake face. The additional thermal transfer was seen to have a significant effect on the material deformation phenomena in the primary shear zone (lowering shear angle) as well as the sliding and sticking conditions of the tool-chip interface. Based on the evidence from this study, it can be concluded that cutting fluid applied towards the flank side of the insert has a significant impact on the cutting process. In particular, if applied in combination with a rake pressure at a similar level, in this case, 8 MPa. © 2021 The Authors
Place, publisher, year, edition, pages
Elsevier Ltd , 2021. Vol. 35, p. 659-674
Keywords [en]
Carbide cutting tools; Carbides; Cutting; Cutting fluids; Morphology; Shear flow; Thermal management (electronics); Turning, Chip segmentation; Lower temperatures; Material deformation; Moderate pressures; Tool-chip contact; Tool-chip contact area; Tool-chip interface; Turning operations, Cutting tools
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
URN: urn:nbn:se:hv:diva-17512DOI: 10.1016/j.cirpj.2021.08.012ISI: 000704828400002Scopus ID: 2-s2.0-85115002466OAI: oai:DiVA.org:hv-17512DiVA, id: diva2:1599208
Funder
Region Västra Götaland
Note
The authors would like to thank both the national funding organizations/projects, Sweden: Västra Götalands Regionen (VGR), PROSAM project (Dnr RUN 612-0974-13) and Czech Republic: This work was supported by the project Novel nanostructures for engineering applications No. CZ.02.1.01/0.0/0.016 026/0008396. We would also like to thank Sandvik Coromant for the support with inserts. A special thanks goes to Andreas Gustafsson at University West and Andreas Lindberg at GKN Aerospace Engine Systems AB for helping with experiments. Sauruck Clemens, Bruker Alicona, Austria in helping with the license of 3-D measurement software.
2021-09-302021-09-302022-01-20