Additive Manufacturing (AM)
DAU GLOSSARY DEFINITION
A process of joining materials to make parts from three-dimensional model data, usually layer by layer, also known as three-dimensional printing.
DoD Instruction 5000.93, Use of Additive Manufacturing in the DoD
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).