Filament extrusion-based additive manufacturing of 316L stainless steel: Effects of sintering conditions on the microstructure and mechanical properties
OPEN ACCESS
Loading...
Author / Producer
Date
2022-11
Publication Type
Journal Article
ETH Bibliography
yes
Citations
Altmetric
OPEN ACCESS
Data
Abstract
Filament extrusion-based additive manufacturing of metals offers an alternative to the widespread beam-based counterparts. The microstructure obtained from extrusion-based techniques differs greatly from the ones obtained by beam-based additive manufacturing, as a sintering process is used, in contrast to the rapid solidification of a melt pool. In this study, the microstructure of 316L stainless steel fabricated by filament extrusion is investigated as a function of debinding and sintering conditions. High-speed nanoindentation correlated with energy-dispersive X-ray mapping is employed for microstructural characterization. High sintering temperatures of 1350 °C, an atmosphere of pure H2, and a cooling rate of 60 K/m are found to result in the optimal microstructure. High densities are obtained due to accelerated densification, enabled by the introduction of diffusion paths due to δ-ferrite formation. At the same time, hard phases like oxides or σ-precipitates with detrimental effects on the mechanical properties can be avoided. It is shown that the porosity can be quantified by analysis of hardness and modulus data from nanoindentation mapping. The values obtained are in good agreement with optical and Archimedes immersion method measurements. Tensile tests of 3D-printed and sintered specimens show excellent ductility and strength in comparison to literature. We demonstrate that 3D printing of 316L filaments and sintering with the optimized conditions results in material properties comparable to bulk values.
Permanent link
Publication status
published
External links
Editor
Book title
Journal / series
Volume
59
Pages / Article No.
103147
Publisher
Elsevier
Event
Edition / version
Methods
Software
Geographic location
Date collected
Date created
Subject
Fused filament fabrication of metals; High-speed nanoindentation mapping; Sintering of 316L steel; Porosity analysis; Fused deposition modeling of metals
Organisational unit
03692 - Spolenak, Ralph / Spolenak, Ralph