What Directed Energy Deposition is

Directed Energy Deposition laser [2].

Directed Energy Deposition (DED) creates pieces by directly melting materials and deposing them on the piece in a layer by layer process. When the material is pushed through the nozzle, energy is focused on the flow, and the material is melted and deposited at the same time [2]. The focused energy source is usually a laser or electron beam, and the energy cource is mounted with a nozzle [2]. Once that layer is solidified, the process repeats until the piece is finished. This process is similar to material extrusion, but it requires more energy and the material can be deposited in several directions [2]. Laser engineered net shaping (LENS), directed light fabrication (DLF), direct metal deposition (DMD), Laser Deposition Welding (LDW), and 3D laser cladding are also process that fall under DED [2, 3].

 


Process

 

  1. An arm with a nozzle moves over the build platform.
  2. Material (wire or powder form) is deposited from the nozzle onto the existing surfaces.
  3. The material is melted using an energy source. These sources can be a a laser, electron beam, or plasma arc.
  4. The model is built up layer by layer [1].

Curing Process

There is no additional process for curing after the piece is made. Post-processing steps may occur only if a certain finish is requested.


Materials

This additive manufacturing technique is mostly used with plastic, metal, ceramic [2].

Equipment Used Today


Applications

Parts can be built from scratch, and DED can also be used to fix complex damaged parts, such as turbine blades or propellers [3].


Pros and Cons

Pros:

  • The ability to control the grain structure to a high degree allows high-quality repairs [1]
  • DED pieces can display mechanical properties comparable to (or better than) those of cast or wrought metals [2]
  • The nature of the DED process doesn’t require gravity, making it a potential process for applications in space [2]
  • LENS process can repair damaged parts that traditional methods can’t otherwise fix [2]

Cons:

  • Finishes can vary depending on paper or plastic material but may require post-processing to achieve the desired effect [1]
  • High equipment cost [2]
  • The speed can often be sacrificed for high accuracy and a pre-determined microstructure [1]
  • Most DED 3D printers are industrial machines with very large footprints that require a closed and controlled environment to operate [3]

Video Demonstration of the Directed Energy Deposition Process

Additive Manufacturing Media. (2019). What Is Directed Energy Deposition? Available at: https://www.youtube.com/watch?v=oPMjaYWM0X0. (12/28/20).



References

[1] https://www.lboro.ac.uk/research/amrg/about/the7categoriesofadditivemanufacturing/directedenergydeposition/

[2] https://all3dp.com/2/main-types-additive-manufacturing/

[3] https://make.3dexperience.3ds.com/processes/directed-energy-deposition

 

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