PBF vs. DED: Which Metal 3D Printing Process Should You Choose?

Metal is one of the most widely used materials, along with plastic, in additive manufacturing. The properties of this material make it suitable for the most demanding markets including for high-performance applications. In this article, we are comparing two of the main metal printing processes: Laser-Powder Bed Fusion (L-PBF) and Directed Energy Deposition (DED). We will be examining the characteristics, most common applications and leading manufacturers of each technology, highlighting their similarities and differences.

To begin with a brief introduction, PBF encompasses several additive manufacturing processes that involve the use of a powder bed, be it plastic, ceramic or metal. As you may have guessed, today we will be focusing on metals. This process can use a laser or an electron beam as an energy source, for example electron beam melting (EBM), introduced by the manufacturer Arcam in 2002. However, in order to compare more directly, we will only be focusing on the process that uses a laser as a heat source. The process is also known by other names, depending on the designations of the various manufacturers, such as DMLS, a term patented in 1994 by EOS, a leader in metal 3D printing. The acronym comes from the German “Direkt Metall Laser Schmelzen” which translates into English as Direct Metal Laser Melting. It can also be called SLM for Selective Laser Melting, a term introduced by the Fraunhofer Institute in 1995.

The PBF process

In contrast, DED is a more recent method than other metal powder bed technologies. It has been known for longer, but has only become truly effective in the last decade. The process uses a material, in powder or wire form, that is melted by a direct energy source while being deposited directly onto the part. The process is best known for its ability to repair and/or coat large metal objects. DED technology can use different energy sources such as laser, plasma or electron beam. For example, WAAM (Wire Arc Additive Manufacturing) technology falls into this category. It is therefore not easy to compare PBF and DED processes, as they are two very different technologies. We will therefore try to understand how they work, how they differ and how they can be complementary.