Additive Manufacturing

additive manufacturing (3d printing)

What is Additive Manufacturing?

Additive Manufacturing is defined as the process of joining materials to make objects from 3D model data.

Unlike traditional mechanical processes, such as CNC milling that starts from a solid piece and “subtract” material (subtractive technologies), Additive Manufacturing (AM) “adds” material layer upon layer.   

With Additive Manufacturing technologies different materials can be processed, such as polymers (different types of plastics), composites (filled plastics), metals. Depending on the material, several additive technologies can be used.

As regard metals, we can recognize Additive Manufacturing technologies according to when the sintering process is performed.  

For metals that undergo an instant sintering:

  • SLM (Selective Laser Melting) — laser source
    The object is built by means of the selective melting of a powder bed
  • DED (Direct Energy Deposition) o LENS (Laser Engineered Net Shaping) — laser source
    The object is built by means of a powder supplied at the sides of the source and then melted 
  • EBM (Electron Beam Melting) — electron beam source
    The object is built by means of the selective melting of a powder bed
  • WAAM (Wire and Arc Additive Manufacturing) — plasma, TIG, MIG/MAG source
    The object is built by means of the fusion of a metal wire-shaped filament

For metals that undergo a post printing sintering:

  • FDM (Fused Deposition Melting) 
    The object is built by means of the fusion of a wire shaped metal-containing plastic filament 
  • BJ (Binder Jetting)
    The object is built by means of the selective deposition of a binder on a powder bed
  • NPJ (Nanoparticle Jetting)
    The object is built by means of the selective deposition of a suspension of nanoparticle in a solvent

It is well known that subtractive and forming technologies (molds and die cast) are largely diffused, thanks to the fact that they allow to produce large amounts of parts using a lot of different materials, but these technologies have limits that Additive Manufacturing does not have. 

What are the benefits of industrial Additive Manufacturing?

  • Total customization (the digital model can be continuously modified and printed)
  • Obtaining of complex geometries not achievable through traditional technologies
  • Reduction of the design costs 
  • Obtaining of objects made by materials normally not processable (e.g. titanium alloys)

How important is gas in the additive process?

In Additivite Manufacturing gas is highly important, it acts on the entire productive process chain, from powders production to the heat treatments performed after the printing process.

Its purity is essential: a not pure gas used during powder production could lead to a high Oxygen content and impurities in the final product. Moreover, during the printing process an impure gas can lead to the formation of oxides that could precipitates in the object: as a consequence these undesired oxides could be potential crack points as well as responsible for poor mechanical properties. 

equipment for additive manufacturing (3d printing)

Thanks to its in-depth knowledge of gases applied to the industrial world, Rivoira has recently developed gas management equipment for the 3D printing process. 

3D Pro® Dry tube

The 3D Pro® Dry Tube is a multilayer tube for the cylinder-printer connection able to avoid Oxygen, moisture and impurities permeability. Using 3D Pro® Dry Tube the purging time of the chamber can be sensitively reduced, since during the use this tube prevent moisture and Oxygen absorption. 

3D Pro® Purifier

3D Pro® Purifier is able to retain pollutants and impurities, leading their content in the gas below the ppm threshold. Thanks to this purifier it is possible to keep constant and very low Oxygen and impurities content during the entire printing process. Hence in this way we can effectively eliminate two parameters from all those managed in this special process.