Article Article
Computed Tomography for the Nondestructive Testing of Additive Manufactured Components: Opportunities and Limitations

The additive manufacturing (AM) process has grown from university research laboratories into a production process for complex-shaped components. Due to the uniqueness of the manufacturing process, new challenges have arisen regarding process control, quality assurance, and surface finishing. This paper will show how the nondestructive radiographic testing (RT) technique computed tomography (CT) can make a valuable contribution to quality assurance at each step of the AM process. The use of CT is demonstrated using an example of chrome-nickel steel nozzles manufactured using the laser powder bed fusion (LPBF) process. The surface of the nozzles is then reworked with the Hirtisation process, a trademarked part finishing technology that is based on a combination of electrochemical pulse methods, hydrodynamic flow and particle assisted chemical removal, and surface treatment. In addition to the already known use of CT for detecting internal discontinuities, CT can be used to ensure sufficient wall thickness, measure internal channel surface roughness, and gauge the geometrical correctness of parts. In this paper, it is demonstrated how to use this RT technique to optimize the design and production process during the component development phase.

DOI: https://doi.org/10.32548/2021.me-04207

References

Aalco, 2020, “Stainless Steel – Austenitic – 1.4404 (316L) Bar and Section,” updated 13 March 2020, https://www.aalco.co.uk/datasheets/Stainless-Steel -14404-316L-Bar-and-Section_39.ashx

ASTM, 2015, ISO/ASTM52900: Standard Terminology for Additive Manufacturing – General Principles – Terminology, ASTM International, West Conshohocken, PA

Cai, Y., Z. Liu, and Z. Shi, 2017, “Effects of Dimensional Size and Surface Roughness on Service Performance for a Micro Laval Nozzle,” Journal of Micromechanics and Microengineering, Vol. 27, No. 5, https://doi.org/10.1088/1361-6439 /aa6552

du Plessis, A., I. Yadroitsev, I. Yadroitsava, and S.G. Le Roux, 2018, “X-Ray Microcomputed Tomography in Additive Manufacturing: A Review of the Current Technology and Applications,” 3D Printing and Additive Manufacturing, Vol. 5, No. 3, pp. 227–247, https://doi.org/10.1089/3dp.2018.0060

Fraunhofer IAPT, 2020, Additive Manufacturing Surface Finishing Study: Benchmark of Surface Finishing Processes for Metal AM Components, Hamburg, Germany

Hansal, W., S. Hansal, R. Mann, and G. Sandulache, 2017, Electropolishing Method and System Therefor, US 20190345628, filed 7 December 2017, and issued 14 November 2019

Kourra, N., J.M. Warnett, A. Attridge, G. Dibling, J. McLoughlin, S. Muirhead-Allwood, R. King, and M.A. Williams, 2018, “Computed Tomography Metrological Examination of Additive Manufactured Acetabular Hip Prosthesis Cups,” Additive Manufacturing, Vol. 22, pp. 146–152, https://doi.org/10.1016/j.addma.2018.04.033

Kruth, J.-P., M. Badrossamay, E. Yasa, J. Deckers, L. Thijs, and J. Van Humbeeck, 2010, “Part and Material Properties in Selective Laser Melting of Metals,” eds. W. Zhao, J. Ye, and D. Zhu, Proceedings of the 16th International Symposium on Electromachining (ISEM XVI), pp. 3–14

Kumbhar, N.N., and A.V. Mulay, 2018, “Post Processing Methods used to Improve Surface Finish of Products which are Manufactured by Additive Manufacturing Technologies: A Review,” Journal of The Institution of Engineers (India): Series C, Vol. 99, pp. 481–487, https://doi.org/10.1007 /s40032-016-0340-z

Oettmeier, K., and E. Hofmann, 2015, “Acceptance of Additive Manufacturing Technologies – An Interdisciplinary Perspective,” EurOMA 2015: 22nd Conference of the European Operations Management Association, Neuchâtel, Switzerland

Petrovic, V., J.V.H. Gonzalez, O.J. Ferrando, J.D. Gordillo, J.R.B. Puchades, and L.P. Griñan, 2011, “Additive Layered Manufacturing: Sectors of Industrial Application Shown through Case Studies,” International Journal of Production Research, Vol. 49, No. 4, pp. 1061–1079, https://doi.org /10.1080/00207540903479786

Saadlaoui, Y., J.-L. Milan, J.-M. Rossi, and P. Chabrand, 2017, “Topology Optimization and Additive Manufacturing: Comparison of Conception Methods Using Industrial Codes,” Journal of Manufacturing Systems, Vol. 43, pt. 1, pp. 178–186, https://doi.org/10.1016/j.jmsy.2017.03.006

Sing, S.L., and W.Y. Yeong, 2020, “Laser Powder Bed Fusion for Metal Additive Manufacturing: Perspectives on Recent Developments,” Virtual and Physical Prototyping, Vol. 15, No. 3, pp. 359–370, https://doi.org/10.1080 /17452759.2020.1779999

Snyder, J.C., and K.A. Thole, 2020, “Tailoring Surface Roughness Using Additive Manufacturing to Improve Internal Cooling,” Journal of Turbomachinery, Vol. 142, No. 7, https://doi.org/10.1115/1.4047380

Stelzer, N., M. Scheerer, Z. Simon, L. Baca, T. Sebald, H. Gschiel, M. Hatzenbichler, and B. Bonvoisin, 2018, “Mechanical Properties of Surface Engineered Metallic Parts Prepared by Additive Manufacturing,” 15th ECSSMET, Noordwijk, The Netherlands

Thompson, A., I. Maskery, and R.K. Leach, 2016, “X-Ray Computed Tomography for Additive Manufacturing: A Review,” Measurement Science and Technology, Vol. 27, No. 7, https://doi.org/10.1088/0957-0233/27/7/072001

Villarraga-Gómez, H., E.L. Herazo, and S.T. Smith, 2019, “X-Ray Computed Tomography: From Medical Imaging to Dimensional Metrology,” Precision Engineering, Vol. 60, pp. 544–569, https://doi.org/10.1016/j.precisioneng.2019.06.007

Yao, Z., J. Stiglich, and T.S. Sudarshan, 1999, “Molybdenum Silicide Based Materials and Their Properties,” Journal of Materials Engineering and Performance, Vol. 8, pp. 291–304, https://doi.org/10.1361/105994999770346837

Zanini, F., E. Sbettega, and S. Carmignato, 2018, “X-Ray Computed Tomography for Metal Additive Manufacturing: Challenges and Solutions for Accuracy Enhancement,” Procedia CIRP, Vol. 75, pp. 114–118, https://doi.org /10.1016/j.procir.2018.04.050

 

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