What is Additive Manufacturing (AM)?
Additive Manufacturing describes a process or “approach” to build tridimensional objects from digital files. AM functions by “adding” material, layer by layer until the object is built. Additive Manufacturing represents a “Technology Classification”, where different specific implementations of this approach can be developed. 3D Printing is one of those technologies covered by this classification, where a nozzle or a LASER “draws” layer after layer with special materials that are melted or bonded together until the final object is created. But 3D Printing is not the only Additive Manufacturing Technology. Another example, one of the oldest available, is Laminated Object Manufacturing or "LOM", in which a LASER or blade cuts out profiles from sheets (paper, ceramics, metals), which forms the layers of the final part. Layers are bonded together using heat activated resin, ultrasonic bonding or other techniques.
As mentioned, AM is a technology and process that manufactures a 3D-solid object from a digital model. AM machines and 3D printers generate 3D solid objects for testing or assembling working mechanisms. AM is an alternative to machine tooling. Reduced hard tooling processes may provide opportunities for manufacturers to present customized products. AM technology has the potential to change the way we add value in various manufacturing settings. For low-volume production demand, AM provides faster lead times than conventional manufacturing methods. Manufacturing systems that have low-volume production, prototyping, and mold mastering are implemented in AM systems .
“Unlike most conventional manufacturing techniques, AM forms objects by building matter up, rather than removing it. Paired with computer-aided design (CAD) software, this technique affords the creation of new types of objects with unique material properties. But while AM is widely billed as ‘the next industrial revolution’, in reality there are still significant hurdles for successful commercialization of the technologies” .
AM systems have been utilized by Fortune 500 companies for a decade, and major progress has been achieved in AM over the last few decades. AM is proving to be an essential element for product designers and engineers. AM users anticipate that, in the future, AM will compete with mass production systems. It proposes new alternatives in shape and function for production .
Traditional machine tooling or "Subtractive Technologies", as CNC equipment, that remove layer by layer of unnecessary material from a solid volume, have many differences and disadvantages over Additive Manufacturing, here a list of some of the most important ones:
- Complexity is free: The cost is less to print a complex part instead of a simple cube of the same size. The more complex (or, the less solid the object is), the faster and cheaper it can be made through additive manufacturing.
- Variety is free: If a part needs to be changed, the change can simply be made on the original CAD file, and the new product can be printed right away.
- No assembly required: Moving parts such as hinges and bicycle chains can be printed in metal directly into the product, which can significantly reduce the part numbers.
- Little lead time: Engineers can create a prototype with a 3-D printer immediately after finishing the part’s stereo lithography (STL) file. As soon as the part has printed, engineers may then begin testing its properties instead of waiting weeks or months for a prototype or part to come in.
- Little-skill manufacturing: While complicated parts with specific parameters and high-tech applications ought to be left to the professionals, even children in elementary school have created their own figures using 3-D printing processes.
- Few constraints: Anything you can dream up and design in the CAD software, you can create with additive manufacturing.
- Less waste: Because only the material that is needed is used, there is very little (if any) material wasted (depend on the AM technology in use, in some case can be even recycled).
- Infinite shades and materials: Engineers can program parts to have specific colors as also material properties in their CAD files, and printers can use a combination of materials and any color to print them (high end multi-material color 3D printers).
Independent of the type of AM machine, in general there are always eight distinct steps in the process sequence:
- Conceptualization and CAD: Design the 3D part/model with Computer Aided Design (CAD) software.
- Conversion to STL: Transform the CAD file from the software format to a more open format as STL.
- Transfer and manipulation of STL file on AM machine: Usually using network, USB or SD cards.
- Machine setup: Configurations on the machine itself.
- Build sequence: Actual building of the 3D object.
- Part removal and cleanup: Remove from the machine, clean and support removable.
- Part post-processing: Surface finishing, hardening, etc.
- Application: Use of the part.
This concludes the summary of the module, Additive Manufacturing.