Additive Manufacturing popularly known as 3D Printing is one of the digital manufacturing processes and a key enabler of Industry 4.0. It is a process of layer-by-layer deposition of material and realizing a 3D object. It can be termed several other names also, based on its application to the manufacturing community. Why additive manufacturing is referred to by different terminology has been discussed in this module. What are the unique capabilities possessed by additive manufacturing and how are they useful in real-life applications have been discussed in this module. Freedom of design, mass customization, waste minimization, and the ability to manufacture complex structures, as well as fast prototyping, are the main benefits of additive manufacturing. In particular, there are some revolutionary applications of AM in biomedical, aerospace, buildings, and protective structures that are discussed in this section. Moreover, based on what criteria the ASTM F42 committee had classified, the AM process is also covered in this module.

Most liquid-based additive manufacturing systems build parts in a vat of photo-curable liquid resin, an organic resin that cures or solidifies under the effect of exposure to light, usually in the UV range. The light cures the resin near the surface, forming a thin hardened layer. Once the complete layer of the part is formed, it is lowered by an elevation control system to allow the next layer of resin to be coated and similarly formed over it. This continues until the entire part is completed. The vat can then be drained and the part removed for further processing, if necessary. There are variations to this technique by the various vendors and they are dependent on the type of light or laser, method of scanning or exposure, type of liquid resin, and type of elevation and optical system used. Different technologies have been developed based on liquid AM by changing its sub-systems, those commercially available tech parts are discussed in this module. Moreover, a deep insight has been made in water based rapid freezing technology and its working conditions.

Sheet based additive manufacturing is also known as laminated object manufacturing or sheet lamination, shares similar fabrication principles with other AM processes. But instead of using liquid or powder or wire as feedstock, sheet lamination uses foil to make an object. This AM technique was first demonstrated by Helisys Inc. Different materials can be processed using this sheet lamination technique like paper, composite, and selective metal lamination. In the paper-based lamination, papers/foils are glued together layer by layer and precisely cut to the designed geometry to make the final object. Potentially any sheet material that can be precisely cut using cutting tools like laser, mechanical cutter, etc., and the same can be bonded using adhesive, soldering, brazing, welding, etc., for part construction. The paper thicknesses usually range from 0.07 to 0.2 mm. Composite lamination has a similar principle, but some reinforcement can be added to the buck material to improve the strength of the fabricated part. Rather than adding glue to all over the layer, a binder can be selectively applied in certain locations of that layer to fabricate the part. Different sheet lamination processes had demonstrated in past years which would be discussed in details in this module.

This module deals with different AM processes which uses wire as a feedstock material to construct a 3D object. The classifications have been made based on various sub-systems used in wire based AM technology. There are multiple options available as wire material like plastic, wax, composites, and metals; each of the material incorporated in part fabrication required different set of machine arrangement. All commercially available wire based AM process have been covered in this module. Moreover, the function of essential accessories and influence of design parameters are also discussed under individual systems. The most important factors in metal wire based AM technology are omnidirectionality, geometric processing, single bead, multi-bead disposition strategy. All mentioned factors need to be thoroughly studied and planned according to machine environment before starting the material deposition or part fabrication.

This module deals with powder based additive manufacturing systems or direct energy deposition. Like wire based AM processes here metallic or ceramic powders are used as a feed stock material to realize an object. There are two types of material handling mechanism involved, one is powder-feed on contentious or pulse setting mode and another is powder-bed. Both approaches have its own benefits and limitations. Moreover, there are processes like selective laser sintering (SLS) and selective laser melting (SLM) in which powder gets partially or completely melted and fused together and bonding takes place between powder molecules. The binder-jetting is also a suitable approach for powder based AM. However, powder based AM systems have different set of subsystems as compared to other AM process. These sub-systems are powder metering, conveyance, and delivery, mainly involved in powder feed unit. Different commercially available powder based AM systems has been discussed with proper video demonstration.