Characterization of Metal Powders Used for Additive Manufacturing

Published

September 16, 2014

Author(s)

John A. Slotwinski, Edward J. Garboczi, Paul E. Stutzman, Chiara F. Ferraris, Stephanie S. Watson, Max A. Peltz

Abstract

Additive manufacturing (AM) techniques can produce complex, high-value metal parts, with potential applications as critical parts such as those found in aerospace components. The production of AM parts with consistent and predictable properties requires input materials with known and repeatable characteristics, which in turn requires standardized measurement methods for powder properties. First, based on our previous work, we assess the applicability of current standardized methods for powder characterization for metal AM powders. Then we present the results of systematic studies carried out on two different powder materials used for additive manufacturing: stainless steel and cobalt-chrome. The characterization of these powders is important in NIST efforts to develop appropriate measurements and standards for additive materials and to document the property of powders used in a NIST-led additive manufacturing material round robin. An extensive array of characterization techniques was applied to these two powders, in both virgin and recycled states. The physical techniques included laser diffraction particle size analysis, X-ray computed tomography for size and shape analysis, and optical and scanning electron microscopy. Techniques sensitive to chemistry, including X-ray diffraction, energy dispersive analytical X-ray analysis using the X-rays generated during scanning electron microscopy, and X-Ray photoelectron spectroscopy were also employed. The results of these analyses show how virgin powder changes after being exposed to and recycled from one or more Direct Metal Laser Sintering (DMLS) additive manufacturing build cycles. In addition, these findings can give insight into the actual additive manufacturing process.

Citation

Journal of Research (NIST JRES) - 119.018

Report Number

119.018

NIST Pub Series

Journal of Research (NIST JRES)

Pub Type

NIST Pubs

Download Paper

https://doi.org/10.6028/jres.119.018

Keywords

Additive manufacturing (AM), Direct Metal Laser Sintering (DMLS), energy-dispersive x-ray, helium pycnometry, laser diffraction, metal powder, powder bed fusion, X-ray computed tomography, X-ray diffraction, scanning Electron Microscopy, X-ray photoelectron spectroscopy

Citation

Slotwinski, J. , Garboczi, E. , Stutzman, P. , Ferraris, C. , Watson, S. and Peltz, M. (2014), Characterization of Metal Powders Used for Additive Manufacturing, Journal of Research (NIST JRES), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/jres.119.018 (Accessed October 31, 2024)