Powder Bed Fusion
Powder bed fusion describes a group of different additive technologies.
These technologies can be separated by the materials being processed.
Most machines process polymers or metals. Ceramics and special sands
can also be processed.
Even by separating the technologies by materials the terminology might be still confusing.
Very similar sounding, trademark protected, names are used for this different technologies.
These are some of the most common used names for powder bed fusion processes:
Selective Laser Melting (SLM™)
Selective Laser Melting is widely used by industry and in academia.
SLM™ is a trademark registered by REALIZER GmbH
Direct Metal Laser Sintering (DMLS)
Direct Metal Laser Sintering is a term used by Electro Optical Systems GmbH
The term was coined in early times when laser power and beam quality were
not sufficient to fully melt the material. Green parts with low density had
to be infiltrated in a second process step. Technology moved on and today
DMLS produces fully dense parts but the term “Sintering” stayed.
LaserCUSING® is a term created and protected by ConceptLaser GmbH a GE company.
However in academic papers and media it is oftentimes referred to SLM
even if the parts have been created on machines from Concept Laser GmbH.
Laser Metal Fusion
Laser Metal Fusion (LMF) is a process name used by TRUMPF
Electron Beam Melting (EBM®)
Electron Beam Melting is a technology by Swedish company ARCAM AB a GE company.
ARCAM is also using the term CAD TO METAL® for the process.
How does powder bed fusion work?
Disregarding the material processed the process is always very similar.
The material is in powder form and spread in a thin layer on a platform.
Energy is applied by laser or electron beam to fuse the cross-section selectively.
The build platform drops by one layer thickness, the next layer is applied and the
new cross-section is fused on top of the previous. The cycle continuous until the
last layer of the part is generated. When the process is finished the platform can be
moved up, not fused powder being extracted and the part be removed.