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AM Terminology

June 29, 2020

Filed under: 3D printing,additive manufacturing — Terry Wohlers @ 09:44

Standard terminology for additive manufacturing and 3D printing is critical when communicating. It puts everyone on the “same page” and more accurately conveys thoughts and ideas when conversing, presenting, and publishing. Ignoring terminology standards and using whichever terms you prefer can cause confusion or worse.

The first version of the ASTM F2792 Standard Terminology for Additive Manufacturing Technologies defined 26 terms and was published in 2009. At the time, I served as the chairman of the ASTM F42.91 Terminology Subcommittee, so the subject is near and dear to my heart. This work led to today’s ISO/ASTM 52900 Standard Terminology for Additive Manufacturing, which is recognized worldwide. It includes nearly five pages of terms, along with additional pages of diagrams and information.

I cringe when I hear non-standard terms when formal industry standard versions are available and were established after a tremendous amount of work by many organizations and bright people worldwide. An example is “selective laser metal (SLM),” a term that some will use instead of metal powder bed fusion (PBF), the correct phrase according to the ISO/ASTM 52900 standard. One problem with using SLM is that it is a part of a company name (SLM Solutions), which offers metal PBF systems. The incorrect use of SLM could lead to a serious blunder when negotiating a legal agreement, for example.

The following are seven key terms and definitions from the ISO/ASTM 52900 standard. They represent the major processes that most AM systems fall within.

  • Material extrusion—an additive manufacturing process in which material is selectively dispensed through a nozzle or orifice
  • Material jetting—an additive manufacturing process in which droplets of build material are selectively deposited
  • Binder jetting—an additive manufacturing process in which a liquid bonding agent is selectively deposited to join powder materials
  • Sheet lamination—an additive manufacturing process in which sheets of material are bonded to form a part
  • Vat photopolymerization—an additive manufacturing process in which liquid photopolymer in a vat is selectively cured by light-activated polymerization
  • Powder bed fusion—an additive manufacturing process in which thermal energy selectively fuses regions of a powder bed
  • Directed energy deposition—an additive manufacturing process in which focused thermal energy is used to fuse materials by melting as they are being deposited

If you are not using these and other industry standard terms, I strongly urge you to do so. It will help with your communication, demonstrate your recognition of international standards, and reduce the possibility of errors and other problems.