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What is Additive Manufacturing?
Additive manufacturing, also known as 3D printing, rapid prototyping or freeform fabrication, is “the process of joining materials to make objects from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing methodologies” such as machining. The term 3D printing can be defined as the fabrication of objects through the deposition of a material using a print head, nozzle, or another printer technology.”
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Additive Manufacturing technologies
There are 2 main families of additive manufacturing technologies
- Powder bed technologies
- Selective Laser Melting (SLM) where the metal powder is melted by a laser beam
- Electron Beam Melting (EBM) where the metal powder is melted by an electron beam after a preheating step
- Precision inkjet printing where the metal powder is mixed with a binder: after the printing operation, the part is consolidated by sintering
- Blown powder technologies, also known as Laser Metal Deposition or Laser cladding
- In this process, the metal powder is blown coaxially to the laser beam which melts the particles on a base metal to form a metallurgical bond when cooled
Selective Laser Melting
Features:
- Complex shapes & internal cavities
- Thin walls & lattice structures
- Better surface finish
Blown Powder Technolgy
Features:
- Both for cladding & Freeform
- Large part size possible
- High powder deposition rates possible
- Use of coarser powders
Inkjet Printing
Features:
- High tolerances, good surface finish & high resolution due to no melting during printing
- Suitable for thin walls & channels as cleaning is facilitated due to no melting during printing
- High productivity for small complex components
- Powder bed technologies
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The key benefits of Additive Manufacturing
- Freedom of design
- Complex shape, inner cavities or foam / lattice structures, impossible to produce by machining
- Thin walls & shapes impossible to produce by casting
- Light weight parts with lattice / foam inner structures
- Flexibility in design changes
- Customized design
- Multiple pieces built as one
- No tool needed
- Short production time (a few hours)
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A wide range of alloys possible
- Titanium alloys
- Aluminium Alloys
- Nickel base alloys
- Cobalt base alloys
- Stainless steels
- Tool steels
- Other Fe base alloys
- Copper base alloys
- Precious metals
- Others
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Metal Powders key features
For additive manufacturing, metal powders should have:
- spherical shape to ensure good flow and coating ability
- particle size usually below 50 μm or below 150 μm depending on machine type and surface finish required
- particle size distribution tailored to the application & properties
- controlled chemical composition
- controlled gas content
A selection of products created using Additive Manufacturing Technology are shown below:
Aerospace
Medical
Automotive, Industrial and Tooling
Consumer Goods