U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.


Secure .gov websites use HTTPS
A lock () or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


  1. Home
  2. Additive Manufacturing (AM)

Additive Manufacturing (AM)


Alternate Definition

A process of joining materials to make parts from three-dimensional model data, usually layer by layer, also known as three-dimensional printing.

Alternate Definition Source

DoD Instruction 5000.93Use of Additive Manufacturing in the DoD

General Information

The American Society for Testing Materials (ASTM) defines seven fundamental processes in the realm of additive manufacturing. Each of these processes utilize different materials which require different 3D printers.  These seven processes are:

Process name Process description
1. Vat photpolymerization An additive manufacturing process in which liquid photopolymer in a vat is selectively cured by light-activated polymerization.
2. Material jetting An additive manufacturing process in which droplets of build material are selectively deposited.
3. Material extrusion An additive manufacturing process in which material is selectively dispensed through a nozzle and solidifies.
4. Powder bed fusion An additive manufacturing process in which thermal energy (laser or electron beam) selectively fuses regions of a powder bed.
5. Binder jetting An additive manufacturing process in which a liquid bonding agent is selectively deposited to join powder materials.
6. Sheet lamination An additive manufacturing process in which sheets of material are bonded to form an object.
7. Directed energy deposition An additive manufacturing process in which focused thermal energy is used to fuse materials by melting as they are being deposited.

The seven types of AM technologies come with various strengths and weaknesses. These strengths and weaknesses range from speed, precision, investment costs, etc. The key is matching the right AM technology to the requirement. These requirements range from simply producing a concept or appearance model to producing form, fit and function models which require much more precise AM technologies. Size of the end item being produced is a major consideration as is trade-offs in speed of production.

Currently within DoD, AM is generally suited for applications that have a low production volume and a complex part geometry. Applications include rapid prototyping like geometric fit checks, scale models, and working prototypes; rapid tooling like sand casts and trimming tools; rapid manufacturing like printed assemblies and legacy part development; repair applications like worn parts and over-machining repairs; and electronic applications like embedded sensors or printed electronics.  

For additional information, please view the many AM videos (links included below) or access the access the interactive AM Community of Practice (CoP).