Page 21 - MSAM-1-1

Materials Science in Additive Manufacturing

ORIGINAL RESEARCH ARTICLE
Plasma spheroidization of gas-atomized 304L

stainless steel powder for laser powder bed
fusion process

1
M. Hossein Sehhat *, Austin T. Sutton , Chia-Hung Hung , Ben Brown ,
2
4
3
5
Ronald J. O’Malley , Jonghyun Park , Ming C. Leu *
1
1
1 Department of Mechanical and Aerospace Engineering, Missouri University of Science and
Technology, Rolla, MO 65409, USA
2 Los Alamos National Laboratory, Los Alamos, NM 87545, USA
3 Department of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan
4 Materials Engineering, Kansas City National Security Campus, Kansas City, MO 64147, USA
5 Department of Materials Science and Engineering, Missouri University of Science and Technology,
Rolla, MO 65409, USA

Abstract

Particles of AISI 304L stainless steel powder were spheroidized by the induction plasma
spheroidization process (TekSphero-15 spheroidization system) to assess the effects of
the spheroidization process on powder and part properties. The morphology of both
as-received and spheroidized powders was characterized by measuring particle size and
shape distribution. The chemistry of powders was studied using inductively coupled
plasma optical emission spectroscopy for evaluation of composing elements, and the
powder’s microstructure was assessed by X-ray diffraction for phase identification and
*Corresponding authors:
M. Hossein Sehhat (hsehhat@mst.edu) by electron backscattered diffraction patterns for crystallography characterization. The
Ming C. Leu (mleu@mst.edu) Revolution Powder Analyzer was used to quantify powder flowability. The mechanical
properties of parts fabricated with as-received and spheroidized powders using laser
Citation: Sehhat MH, Sutton AT,
Hung CH, et al., 2022, Plasma powder bed fusion process were measured and compared. Our experimental results
spheroidization of gas-atomized showed that the fabricated parts with plasma spheroidized powder have lower
304L stainless steel powder for tensile strength but higher ductility. Considerable changes in powder chemistry
laser powder bed fusion process.
Mater Sci Add Manuf, 1(1): 1. and microstructure were observed due to the change in solidification mode after
https://doi.org/10.18063/msam.v1i1.1 the spheroidization process. The spheroidized powder solidified in the austenite-to-
Received: February 4, 2022 ferrite solidification mode due to the loss of carbon, nitrogen, and oxygen. In contrast,
the as-received powder solidified in the ferrite-to-austenite solidification mode. This
Accepted: February 23, 2022
change in solidification mode impacted the components made with spheroidized
Published Online: March 18, 2022 powder to have lower tensile strength but higher ductility.
Copyright: © 2022 Author(s).
This is an Open Access article
distributed under the terms of the Keywords: Powder characteristics; Mechanical properties; Plasma spheroidization; Laser
Creative Commons Attribution powder bed fusion; Additive manufacturing; 304L stainless steel
License, permitting distribution,
and reproduction in any medium,
provided the original work is
properly cited.
1. Introduction
Publisher’s Note: Whioce
Publishing remains neutral with Additive manufacturing (AM) is poised to revolutionize the way components are created
regard to jurisdictional claims in
published maps and institutional by enabling the construction of complex geometries and allowing more freedom and
affiliations. flexibility during the design process [1,2] . AM can unify all the steps of a conventional

Volume 1 Issue 1 (2022) 1 http://doi.org/10.18063/msam.v1i1.1