Links Between Machining Parameters and Surface Integrity in Drilling Ni-Superalloy

Abstract:

In aerospace industry, the manufacturing of critical parts (high energy components) requires an important validation process to guarantee the quality of the produced parts, and thus their fatigue lifecycle. Globally, this validation consists in freezing the cutting conditions using metallurgical analysis or fatigue trials, and a test on the first article. This process is extremely complex and expensive. In this way establishing the correlation between the cutting conditions and the surface integrity will help us to optimize the manufacture of those parts. In this article, by the means of an experimental method, we define a domain of validation by combining the cutting conditions according to the classic criteria established by AFNOR E66-520 norm (Couple-Tool-Material) and the criteria of surface integrity for the drilling of a Nickel-base superalloy. The experimental device consists in drilling a Ø15.5 mm hole on a 3-axis milling centre instrumented by a 4 components Kistler dynamometer (Fx, Fy, Fz and Mz), a spindle power sensor “Watt-pilote” and three accelerometers placed following the directions X, Y and Z. Scanning Electron Microscopy (SEM) observations, micro-hardness tests and topographic measurements with an optical profilometer, are carried out to characterize the metallurgical state of the holes manufactured. Finally, correlations were respectively made between the cutting conditions, the recorded signals and the metallurgical state of the holes.

• Periodical: Advanced Materials Research (Volume 112)
• Pages: 171-178
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.112.171
• Online since: May 2010
• Authors: Vincent Dutilh, Gilles Dessein, Joel Alexis, Géraldine Perrin
• Keywords: Drilling, Process Monitoring, Surface Integrity, Udimet 720

References

[1] H.T. Pang, P.A.S. Reed. Microstructure effects on high temperature fatigue crack initiation and short crack growth in turbine disc nickel-base superalloy Udimet 720Li. Journal of Materials Science and Engineering, A 448, 67-79 (2006).

DOI: 10.1016/j.msea.2006.11.016

[2] G. Perrin. Étude métallurgique, mécanique et thermique de l'intégrité de surface des pièces percées au foret hélicoïdal dans l'Inconel 718TR - Détection et quantification des anomalies par Process Monitoring. Thèse de doctorat, Ecole des Mines de Paris (2004).

DOI: 10.1051/ptox/2009015

[3] A. Sharman, A. Amarasinghe, and K. Ridgway. Tool life and surface integrity aspects when drilling and hole making in Inconel 718. Journal of Materials Processing Technology , 200, 424-432 (2008).

DOI: 10.1016/j.jmatprotec.2007.08.080

[4] J. Kwong, D. Axinte, and P. Withers, The sensitivity of Ni-based superalloy to hole making operations: Influence of process parameters on subsurface damage and residual stress. Journal of Materials Processing Technology, In Press, Corrected Proof, (2008).

DOI: 10.1016/j.jmatprotec.2008.09.014

[5] E.O. Ezugwu. Key improvements in the machining of difficult-to-cut aerospace superalloys. International Journal of Tools & Manufacture 45, 1353-1367 (2005).

DOI: 10.1016/j.ijmachtools.2005.02.003

[6] A. Sharman, J. Hughes, and K. Ridgway. An analysis of the residual stresses generated in Inconel 718(TM) when turning. Journal of Materials Processing Technology , 173, 359-367 (2006).

DOI: 10.1016/j.jmatprotec.2005.12.007

[7] MANHIRP Project. Integrating Process Controls with Manufacturing to Produce High Integrity Rotating Parts for Modern Gas Turbines. Final Report (2005).

[8] D. Novovic, R. C. Dewes, D. K. Aspinwall, W. Voice, and P. Bowen. The effect of machined topography and integrity on fatigue life. International Journal of Machine Tools and Manufacture, 44, 125-134 (2004).

DOI: 10.1016/j.ijmachtools.2003.10.018

[9] AFNOR Norm NF E66-520 . Working zones of cutting tools - Couple tool-material (2000).