Page 19 - MSAM-1-2

Materials Science in Additive Manufacturing

ORIGINAL RESEARCH ARTICLE
Influence of powder morphology on laser

absorption behavior and printability of
nanoparticle-coated 90W-Ni-Fe powder during

laser powder bed fusion

Jingjia Sun, Meng Guo, Keyu Shi, Dongdong Gu*
Jiangsu Provincial Engineering Laboratory for Laser Additive Manufacturing of High-Performance
Metallic Components, College of Materials Science and Technology, Nanjing University of
Aeronautics and Astronautics, Nanjing, China

Abstract

In this work, mesoscopic simulation and experimental studies were applied to
investigate the influence of powder morphology and characteristics on laser
absorption behavior and printability of nanoparticle-coated 90W-Ni-Fe powder
during laser powder bed fusion (LPBF). The mechanism of laser-material interaction
and the thermal behavior of molten fluid during LPBF were revealed, thereby
optimizing the powder preparation parameters. It showed that when the powder
preparation parameters were optimized (i.e., ball-to-powder weight ratio of 1:2,
milling speed of 250 rpm, and milling time of 6 h), the Ni and Fe nanoparticles were
uniformly dispersed on W particles and, meanwhile, the sufficiently high sphericity of
*Corresponding author: the W matrix particles was maintained. The nanoparticle-coated 90W-Ni-Fe powder
Dongdong Gu had a sound laser absorption behavior with laser absorptivity of 93.51%, leading to
(dongdonggu@nuaa.edu.cn) the high LPBF printing quality with a smooth surface free of balling phenomenon
Citation: Sun J, Guo M, Shi K, and microcracks. Specimen fabricated using optimally prepared powder has a
et al., 2022, Influence of powder high density of 98% and a low surface roughness of 7.91 μm. The LPBF-processed
morphology on laser absorption
behavior and printability of 90W-Ni-Fe alloys had a uniform hardness distribution with an average value of
nanoparticle-coated 90W-Ni-Fe 439.47 HV and significantly enhanced compression properties with compressive
1
powder during laser powder bed strength of 1255.35 MPa and an elongation of 24.74%. The results in this work
fusion. Mater Sci Add Manuf. 1(2): 11.
http://doi.org/10.18063/msam.v1i2.11 provided a physical understanding of complex and interdependent laser-powder
interaction and melt pool formation mechanisms during LPBF of W-based alloys that
Received: April 11, 2022 are governed by powder characteristics.
Accepted: May 30, 2022
Published Online: June 14, 2022 Keywords: Laser powder bed fusion; Powder morphology; Laser absorption behavior;
Copyright: © 2022 Author(s). Mechanical properties
This is an Open Access article
distributed under the terms of the
Creative Commons Attribution
License, permitting distribution,
and reproduction in any medium, 1. Introduction
provided the original work is
properly cited. W-Ni-Fe has attracted a great deal of attention in the fields of national defense, industry, and
Publisher’s Note: Whioce military due to its high density, high melting point, and extremely low thermal expansion
Publishing remains neutral with coefficient [1,2] . However, at present, they are usually fabricated by conventional powder
regard to jurisdictional claims in
published maps and institutional metallurgy technique based on liquid phase sintering, which is characterized by costly
affiliations. mold cycles and difficulty in completely melting W particles, limiting the application of

Volume 1 Issue 2 (2022) 1 http://doi.org/10.18063/msam.v1i2.11