Additive manufacturing and industrial 3D printing technologies
Additive manufacturing processes or industrial 3D printing systems allow the design of new parts with complex geometries, or with new functionalities in sectors as varied as the aeronautics industry, energy, the manufacture of tools or prototypes. All have one thing in common: the construction of an object by adding material, thanks to the successive deposit of a thin layer of material.
In most additive manufacturing processes, throughout the value chain, gases provide essential functions to guarantee the final quality or parts and reduce their production time:
- Process safety (protection against the risk of ignition or powders)
- Protection against oxidation and humidity of materials
Find all our solutions for additive manufacturing
Air Liquide offers gases and gas mixtures that meet the quality requirements of all techniques related to additive manufacturing.
Air Liquide solutions for additive manufacturing processes
Air Liquide supports you in the development of the production of parts by additive manufacturing and offers you the best gas solutions according to your type of production process.
The manufacture of metal powders
The metal powders often used in the additive manufacturing method are mainly produced by a so-called gas atomisation system. The stability of production parameters such as the pressure and temperature of Argon or Nitrogen is crucial to ensure the quality of the powders produced in order to optimize the particle size of the powders for the additive manufacturing market.
The quality of the parts depends on the quality of the powders. Proper conservation and controlled recycling helps to limit their oxidation.
The manufacture of parts with the different 3D printing technologies
The different process families are classified according to ISO and ASTM standards:
- Material Extrusion: wire extrusion process (Fused Deposition Modeling / FDM). Beyond applications for 3D printing intended for the general public, also used in industrial manufacturing.
- Binder Jetting: materials ranging from ceramics, polymers and plastics, to certain metals in powder form.
- Projection of materials (Material Jetting): fine particles are deposited then solidified (ex: photopolymers).
- Deposition of matter under concentrated energy (Directed Energy Deposition / DED): the printing material is directly melted by an energy source using a laser or an electric arc. Argon and Ar-CO2 mixtures are used here.
- Powder bed fusion (PBF) for metals, plastics or polymers already makes it possible today to produce many industrial parts in series production. The energy source of the powder bed fusion process is often a Laser (Selective Laser Melting / SLM, Selective Laser Sintering / SLS, Direct Metal Laser Sintering / DMLS…). Argon or nitrogen are used as shielding gases. The electron beam (Electron Beam Melting EBM) is sometimes encountered for metal parts. In this case, helium is used with a low helium back pressure to avoid splashing.
- Lamination of layers (Sheet Lamination / SL): technique for printing by superimposing successive layers of sheets bound or glued together by binder.
- In-vessel photopolymerization (Vat Photopolymerization) such as stereolithography (SLA) which selectively solidifies a liquid photopolymer.
Additive manufacturing and finishing operations
After the construction phase, the parts are subject to finishing operations:
- Cooling under neutral atmosphere, nitrogen or argon.
- The removal of the supports, made with the part
- Cleaning, possibly with the cleaning process with carbon dioxide in supercritical form.
- Stress relieving treatment to evacuate residual stresses
- Possible additional heat treatments under controlled atmosphere to give the parts the mechanical characteristics
- Surface treatment to achieve the targeted surface condition (roughness for example) or machining, or cryo machining (oil-free) if necessary
Additive manufacturing is in constant development, the news is full of innovations. In recent years, the substitution of traditional manufacturing methods by additive manufacturing technologies has undeniably had advantages (optimized design, lighter parts, rapid prototyping, simplification of the supply chain, optimization of the overall cost of the part, etc.). To take full advantage of this potential, this manufacturing method should be considered right from the part design stage.