Page 39 - MSAM-4-2

Materials Science in Additive Manufacturing Measuring the porosity of AM components

A B

Figure 8. Comparison of the variance and range of the analyzed density measurement methods for the individual additive printing processes
Abbreviations: EBM: Electron beam melting; FDM: Fused deposition modeling; LCM: Lithography-based ceramic manufacturing; SLS: Selective laser sintering
A B (B) Sintered parts

Sintered components made from 316L metal filament have
a different pore size and pore structure than the printed
316L green parts. The basic 316L filament consists of a
mixture of polymer binders and metal particles and is only
converted into a dense metal part after the printing process
through debinding and sintering processes. The pores
change in the various process phases from the green part
to the sintered component. After debinding, the polymer
components are largely removed, creating additional
open pores in the green part. During sintering, the metal
particles combine and sinter to form a dense component.
Due to incomplete fusion of the metal particles during
sintering, open and closed pores continue to occur. The
Figure 9. Micrographs (top) and binary images created using ImageJ pore size is usually smaller than the initial pore size of
(bottom) for micrograph analyses of FDM green parts made of 316L. the green parts after printing, but can still be in the range
(A) Section parallel to the build direction; (B) section perpendicular to
the build direction. Scale bar: 500 μm of a few micrometers. This means that the samples can
Abbreviation: FDM: Fused deposition modeling. also be easily analyzed with the measurement methods

Volume 4 Issue 2 (2025) 13 doi: 10.36922/MSAM025090010