associated with too many suppliers of individual parts drops; (vi) better overall performance, as it enables geometries that are desirable but cannot be made with conventional manufacturing.
AM allows for parts consolidation, even removing the need for assembly in some cases. Several applications of AM have obvious benefits for fostering product performance through lightweighting/consolidation without compromising high strength are: optimizing heat sinks to dissipate heat flux better, optimizing fluid flow to minimize drag forces, and optimizing energy absorption to minimize energy consumption. Figure 1.5 shows an example conducted by GE Additive. Almost 300 parts were consolidated in one part for the A‐CT7 engine frame. This consolidation also reduced the seven assemblies to one where more than 10‐pound weight was chopped off.
Figure 1.5 Consolidation of around 300 parts to one part printed by AM.
Source: Courtesy of GE Additive, open access [7], reproduced under the Creative Commons License.
Functionally graded materials (FGMs) and structures (FGSs): The integration of multiple advanced materials into one component is one of the most rapidly developing areas of AM technology. The capability to create multiphase materials with gradual variations in compositions is one of the important features of AM. During the layer‐by‐layer step of AM processes, the material composition can gradually be altered to obtain the desired functionality. AM also enables the development of FGSs with a single‐phase material, where the density is gradually changed through the addition of cellular/lattice structures; and embedding objects (e.g. sensors) within structures. Among AM processes, DED is the most promising technology to develop such structures, where different powders can be switched insitu to develop desired composition and alloys. Figure 1.6 shows different FGMs that can effectively be developed by DED. Figure 1.7 shows a cutting tool with an embedded fiber optic, as an FGS, developed by an AM‐based process.
Parts with conformal cooling channels for increased productivity: Cooling systems play a vital role in the productivity and performance of many parts. For example, in an injection molding process, the cooling period of a production cycle counts for more than 40% of cycle time. If this period drops by means of taking the heat out of the mold, the productivity increases dramatically. In an active antenna, developing conformal channels will be very important as the generated heat can be dissipated from the zone much effectively, not to affect the antenna performance. With AM, designers can have much more freedom to incorporate conformal cooling channels into their designs that facilitates uniform cooling over the entire surface. Sub‐conformal channels can be included in the optimization process. Figure 1.8 shows a design of an insert used in molds. The design includes a conformal cooling channel wherein the support cells are used to enhance the heat transfer.
Parts repair and refurbishment: Machining errors or last‐minute engineering changes can affect on‐time delivery of tooling and potentially impact the introduction date of a new product. AM, especially DED processes, can be applied as a safe technology to repair tooling, especially on critical contacting surfaces. AM increases tool life and, in many cases, can save a high‐value tool that would otherwise need to be replaced. Figure 1.9 shows an LDED process used in the in‐situ repair of turbine blades.
Figure 1.6 Functionally graded materials (FGMs); (a) Laser DED with multiple powder feeders is widely used for FGMs; (b) FGM with two alloys with gradual interface (c) FGM with two alloys with one sharp interface, (d) FGM with multiple interfaces, (e) FGM with three alloys, (f) FGM with selective deposition of secondary alloy.
Source: Redrawn and adapted from [8].
Figure 1.7 A fiber optic embedded in a metallic cutting part using a combined AM‐based process.
Source: Republished with permission from Elsevier [9].
Figure 1.8 A mold insert with (a) conformal cooling channels, (b) conformal and lattice structures to improve heat dissipation.
Source: Republished with permission from Elsevier [10].
Figure 1.9 LDED used to rebuild turbine blades.
Source: Courtesy of Rolls Royce [11].
A solution to supply shortages in critical crises: Interruption to the global supply chain during crises can be catastrophic to the health and well‐doing of society. The 2020 pandemic is evidence of how the supply chain of medical supplies could have been affected. AM processes can provide remedies during such crises. In March 2020, the 3D printing community got together to help in making medical devices during a very hectic period when medical centers were suffering from a lack of personal protective equipment (PPE). For example, the 3D printing community of the Waterloo region of Canada responded to the call from a local company called InkSmith to locally produce parts of PPEs. The call was received very well, and in a short period of time, more than 200 000 face shields were made and donated to hospitals until the global supply chain started to provide supplies seamlessly. The same model can be used in any crisis. The governments should proactively develop a workflow for critical crises when the AM community can be of tremendous help.
An effective solution to localized manufacturing: The 2020 pandemic has changed the world forever. The globalization idea has been hammered, and governments are now incentivizing local manufacturing to boost not only local communities but also be ready for future crises. AM will play an important role in the realization of local manufacturing. Besides, as reported in [12], more innovators and user entrepreneurs are turning into on‐demand manufacturers, utilizing the opportunities of access to flexible local production. Further advancements in AM will shift the production of innovative products from a centralized to a local production platform. A shift toward local manufacturing has been started.
Health and humanitarian
