Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Process and feedstock driven microstructure for laser powder bed fusion of 316L stainless steel

Journal Article · · Materialia
 [1];  [1];  [1];  [1];  [1];  [2]
  1. Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
  2. Univ. of Tennessee, Knoxville, TN (United States)

Here in the pursuit of improving additively manufactured (AM) component quality and reliability, fine-tuning critical process parameters such as laser power and scan speed is a great first step toward limiting defect formation and optimizing the microstructure. However, the synergistic effects between these process parameters, layer thickness, and feedstock attributes (e.g. powder size distribution) on part characteristics such as microstructure, density, hardness, and surface roughness are not as well-studied. In this work, we investigate 316L stainless steel density cubes built via laser powder bed fusion (L-PBF), emphasizing the significant microstructural changes that occur due to altering the volumetric energy density (VED) via laser power, scan speed, and layer thickness changes, coupled with different starting powder size distributions. This study demonstrates that there is not one ideal process set and powder size distribution for each machine. Instead, there are several combinations or feedstock/process parameter ‘recipes’ to achieve similar goals. This study also establishes that for equivalent VEDs, changing powder size can significantly alter part density, GND density, and hardness. Through proper parameter and feedstock control, part attributes such as density, grain size, texture, dislocation density, hardness, and surface roughness can be customized, thereby creating multiple high-performance regions in the AM process space.

Research Organization:
Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA)
Grant/Contract Number:
NA0003525
OSTI ID:
1855797
Alternate ID(s):
OSTI ID: 1962148
Report Number(s):
SAND2022-2187J; 703695
Journal Information:
Materialia, Journal Name: Materialia Vol. 21; ISSN 2589-1529
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English

References (18)

Density of additively-manufactured, 316L SS parts using laser powder-bed fusion at powers up to 400 W journal May 2014
The role of particle size on the laser sintering of iron powder journal October 2004
The role of process variables in laser-based direct metal solid freeform fabrication journal September 2001
Overview of Materials Qualification Needs for Metal Additive Manufacturing journal January 2016
Assessment of geometrically necessary dislocation levels derived by 3D EBSD journal October 2015
Effect of selective laser melting (SLM) process parameters on microstructure and mechanical properties of 316L austenitic stainless steel journal November 2017
Texture control of 316L parts by modulation of the melt pool morphology in selective laser melting journal February 2019
Effect of process parameters on the microstructure, tensile strength and productivity of 316L parts produced by laser powder bed fusion journal January 2020
Selective laser melting of stainless steel 316L with low porosity and high build rates journal August 2016
On the limitations of Volumetric Energy Density as a design parameter for Selective Laser Melting journal January 2017
Influence of laser processing parameters on the surface characteristics of 316L stainless steel manufactured by selective laser melting journal January 2020
Variation of elastic mechanical properties with texture, porosity, and defect characteristics in laser powder bed fusion 316L stainless steel journal August 2019
3D printing of Aluminium alloys: Additive Manufacturing of Aluminium alloys using selective laser melting journal December 2019
About quantitative EBSD analysis of deformation and recovery substructures in pure Tantalum journal August 2015
Application of dimensional analysis to selective laser melting journal January 2008
Power–Velocity Process Design Charts for Powder Bed Additive Manufacturing journal August 2017
New parameter of roundness R: circularity corrected by aspect ratio journal January 2016
Measurement Science Needs for Real-time Control of Additive Manufacturing Powder Bed Fusion Processes report February 2015