Keywords
Inconel 718
PCBN microgeometry
cutting forces
surface roughness
tool wear
How to Cite
Abstract
This study investigates the effect of cutting edge microgeometry on the milling of Inconel 718, a superalloy widely used in aircraft engine components. Face milling tests were conducted using a Ø63 mm tool with unevenly distributed polycrystalline cubic boron nitride (PCBN) inserts, comparing inserts with a chamfered cutting edge (15° × 0.2 mm) and sharp cutting edges. The experiments examined cutting forces, surface roughness (parameters Ra and Rz), and tool wear at various cutting speeds (80–300 m/min). The results revealed that sharp inserts generated lower cutting forces compared to chamfered inserts, with the axial force being the greatest component for chamfered tools and the lowest for sharp ones. The dominant tool wear mechanism for both insert types was chipping; however, sharp inserts also exhibited built–up edge formation and, in one case, a significantly deeper crater compared to chamfered inserts which showed smaller crater depths. The study concludes that the cutting edge microgeometry significantly influences the machining performance in terms of cutting forces, surface quality, and tool wear when milling Inconel 718.
References
Breidenstein, B., Grove, T., Krödel, A., & Sitab, R. (2019). Influence of hexagonal phase transformation in laser prepared PcBN cutting tools on tool wear in machining of Inconel 718. Metal Powder Report, 74(5), 237–243. https://doi.org/10.1016/j.mprp.2018.12.077
Bushlya, V., Zhou, J., & Ståhl, J. E. (2012). Effect of cutting conditions on machinability of superalloy Inconel 718 during high speed turning with coated and uncoated PCBN Tools. Procedia CIRP, 3, 370–375. https://doi.org/10.1016/j.procir.2012.07.064
Chen, L., Stahl, J. E., Zhao, W., & Zhou, J. (2018). Assessment on abrasiveness of high chromium cast iron material on the wear performance of PCBN cutting tools in dry machining. Journal of Materials Processing Technology, 255, 110–120. https://doi.org/10.1016/j.jmatprotec.2017.11.054
Denkena, B., Grove, T., Krödel, A., & Ellersiek, L. (2018). Increased performance in high speed turning of Inconel 718 by laser structuring of PcBN tools. Procedia CIRP, 77, 602–605. https://doi.org/10.1016/j.procir.2018.08.202
Dogra, M., Sharma, V. S., Sachdeva, A., Suri, N. M., & Dureja, J. S. (2010). Tool wear, chip formation and workpiece surface issues in CBN hard turning: A review. International Journal of Precision Engineering and Manufacturing, 11(2), 341–358. https://doi.org/10.1007/s12541-010-0040-1
ElementSix™. (2025). Precision machining: Giving toolmakers a competitive edge. Retrieved May 4, 2025, from https://e6-prd-cdn-01.azureedge.net/mediacontainer/medialibraries/element6/documents/brochures/ element-six-metalworking-brochure-en.pdf?ext=.pdf
Gutnichenko, О., Bushlya, V., Zhou, J., & Ståhl, J. E. (2014). Influence of cutting speed and tool wear on vibrations and process stability when turning Inconel 718 with PCBN tools. International Journal of Manufacturing Research, 9(2), 173–193. https://doi.org/10.1504/IJMR.2014.062444
International Organization for Standardization. (1989). Tool life testing in milling Part 1: Face milling (ISO Standard No. 8688-1:1989). https://www.iso.org/standard/16091.html
International Organization for Standardization. (2017). Balancing of rotating tools and tool systems (ISO Standard No. 16084:2017). https://www.iso.org/standard/68452.html
Jacquet, T., Fromentin, G., Prat, D., & Viprey, F. (2024). Modeling of high-feed milling and surface quality applied to Inconel 718. Procedia CIRP, 123, 113–118. https://doi.org/10.1016/j.procir.2024.05.022
Jeyapandiarajan, P.,& Anthony, X. M. (2019). Influence of cutting condition on machinability aspects of Inconel 718. Journal of Engineering Research, 7(2), 315-332.
Lindvall, R., Lenrick, F., Persson, H., M’Saoubi, R., Ståhl, J. E., & Bushlya, V. (2020). Performance and wear mechanisms of PCD and pcBN cutting tools during machining titanium alloy Ti6Al4V. Wear, 454–455, Article 203329. https://doi.org/10.1016/j.wear.2020.203329
Liu, H., Meurer, M., & Bergs, T. (2024). Surface integrity analysis in orthogonal milling of Inconel 718. Procedia CIRP, 123, 191–196. https://doi.org/10.1016/j.procir.2024.05.035
Piorkowski, P., Borkowski, W., & Skoczynski, W. (2024). Comprehensive evaluation method for high-performance milling of Inconel 718 Alloy. Applied Sciences, 14(19), Article 19. https://doi.org/10.3390/app14199023
Rolled Alloys. (n.d.). 718 (AMS 5663). Retrieved May 4, 2025, from https://www.rolledalloys.com/products/nickel/alloy-718-ams5663/
Smak, K., Szablewski, P., Legutko, S., Petru, J., Kratochwil, J., & Wencel, S. (2024). Evaluation of the influence of the tool set overhang on the tool wear and surface quality in the process of finish turning of the Inconel 718 alloy. Materials, 17(18), Article 18. https://doi.org/10.3390/ma17184465
Society of Automotive Engineers. (1965a). Alloy Bars, Forgings, and Rings, Corrosion And Heat RESISTANT Nickel Base - 19Cr - 3.1Mo - 5.1(Cb + Ta) - 0.90Ti - 0.50Al Consumable Electrode or Vacuum Induction Melted, Solution Treated (SAE Standard No. AMS5662). https://www.sae.org/standards/content/ams5662/
Society of Automotive Engineers. (1965b). Alloy bars, forgings, and rings, corrosion and heat resistant nickel base - 19Cr - 3.1Mo - 5.1(Cb + Ta) - 0.90Ti - 0.50Al solution and precipitation heat treated consumable electrode or vacuum induction melted (SAE Standard No. AMS5663). https://www.sae.org/standards/content/ams5663/
Sommer, D., Hornung, S., Esen, C., & Hellmann, R. (2024). Surface roughness optimization of hybrid PBF-LB/M-built Inconel 718 using in situ high-speed milling. The International Journal of Advanced Manufacturing Technology, 132(3), 1741–1751. https://doi.org/10.1007/s00170-024-13382-5
Tsai, M. H., Chen, T. H., Lee, J. N., Hsu, T. L., & Huang, D. K. (2024). Five-axis finish milling machining for an Inconel 718 alloy monolithic blisk. Applied Sciences, 14(10), Article 10. https://doi.org/10.3390/app14104015
Veeranaath, V. (2018). Experimental investigation of process parameters in orthogonal machining of Ti6Al4V with TiC coated PCBN inserts – A finite element analysis. Materials Today: Proceedings, 5(9), 19547–19554. https://doi.org/10.1016/j.matpr.2018.06.316
Wang, G., Zhou, X., Wu, X., & Ma, J. (2019). Failure and control of PCBN tools in the process of milling hardened steel. Metals, 9(8), Article 8. https://doi.org/10.3390/met9080885
Yevdokymov, O., Kolesnyk, V., Peterka, J., Vopat, T., Gupta, M. K., Lisovenko, D., & Dovhopolov, A. (2023). Pareto analysis of machining factors significance when turning of nickel-based superalloy Inconel 718. Metals, 13(8), Article 8. https://doi.org/10.3390/met13081354
Zhou, J., Bushlya, V., Peng, R. L., Chen, Z., Johansson, S., & Stahl, J. E. (2014). analysis of subsurface microstructure and residual stresses in machined Inconel 718 with PCBN and Al2O3-SiCw tools. Procedia CIRP, 13, 150–155. https://doi.org/10.1016/j.procir.2014.04.026