Porosity Measurements and Analysis for Metal Additive Manufacturing Process Control

Published

September 16, 2014

Author(s)

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

Abstract

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.

Citation

Journal of Research (NIST JRES) - 119.019

Report Number

119.019

NIST Pub Series

Journal of Research (NIST JRES)

Pub Type

NIST Pubs

Download Paper

https://doi.org/10.6028/jres.119.019

Keywords

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

Citation

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], https://doi.org/10.6028/jres.119.019 (Accessed October 26, 2025)