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Porosity Measurements and Analysis for Metal Additive Manufacturing Process Control



John A. Slotwinski, Edward J. Garboczi, Keith M. Hebenstreit


Additive manufacturing techniques can produce complex, high-value metal parts, with potential applications as critical metal components such as those found in aerospace engines and as customized biomedical implants. Material porosity in these parts is undesirable for aerospace parts - since porosity could lead to premature failure - and desirable for some biomedical implants - since surface-breaking pores allows for better integration with biological tissue. Changes in a part's porosity during an additive manufacturing build may also be an indication of an undesired change in the build process. Here, we present efforts to develop an ultrasonic sensor for monitoring changes in the porosity in metal parts during fabrication on a metal powder bed fusion system. The development of well-characterized reference samples, measurements of the porosity of these samples with multiple techniques, and correlation of ultrasonic measurements with the degree of porosity is presented. A proposed sensor design, measurement strategy, and future experimental plans on a metal powder bed fusion system are also presented.
Journal of Research (NIST JRES) - 119.019
Report Number


Additive manufacturing, Archimedes, cobalt-chrome, Direct Metal Laser Sintering, porosity, powder bed fusion, ultrasonic NDT, X-Ray Computed Tomography


Slotwinski, J. , Garboczi, E. and Hebenstreit, K. (2014), Porosity Measurements and Analysis for Metal Additive Manufacturing Process Control, Journal of Research (NIST JRES), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed June 15, 2024)


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Created September 16, 2014, Updated November 10, 2018