ADDITIVE MANUFACTURING: Revolutionizing industries around the world

Additive Manufacturing

Additive manufacturing technology provides the ability and accessibility to custom-create products, and in the process aims to redefine the current manufacturing scenario.

This article provides a concise analysis of all aspects surrounding additive manufacturing. It lays out the tools necessary to help with your prospective manufacturing ventures.

In this deep-dive, we aim to cover the following ideas:

  • What is Additive Manufacturing (AM)?
  • How does it work?
  • Types of additive manufacturing
  • Additive manufacturing technologies
  • Materials used in additive manufacturing
  • Advantages of additive manufacturing
  • Applications of additive manufacturing

What is Additive Manufacturing?

Additive manufacturing (AM) is the customary industrial production term for 3D printing. A revolutionary approach, it stacks layer upon layer of the primary material. Computer-controlled processes are a major factor of AM, enabling the manufacturing of stronger, lighter, and cheaper products. Meanwhile, its traditionally manufactured counterparts are often heavier, costlier, and difficult to produce.

Additive manufacturing is often lumped together with 3D printing. But it is in fact an umbrella term, that encompasses processes such as Rapid Prototyping (RP), and Direct Digital Manufacturing, and of course, 3D printing.

How does it work?

AM technologies often rely on computer-aided design (CAD) or 3D object scanners. It directs custom-designed machinery to deposit layers of the material with geometric precision. The object builds from the ground up by adding upon layers of the material, in direct contrast to the traditional manufacturing methods. There, they often reduce the required product to the requisite shape using tedious methods like machining, milling or carving out the surplus material.

AM technologies often rely on computer-aided design (CAD) or 3D object scanners. It directs custom-designed machinery to deposit layers of the material with geometric precision.
Computer-Aided Design (Image Courtesy Cad, Design, Mechanical by Ye_Olde_Inke_Pot Licensed under Pixabay)

The digital 3D-scanned object is then “sliced” using another purpose-built software. This, in effect, literally slices the 3D model of the object into two-dimensional slices that the printer can read and print one slice at a time.

3D model Slicing
3D model Slicing

The additive layer technology might seem rather simplistic in its purview. And the needs of the consumers are ever so diverse. To save the day, a host of sophisticated collaborative technology exists to combat it. The following section strives to elaborate further.

Additive manufacturing: types and technologies

There are 10 variants of Additive manufacturing to suit a host of applications. 

  1. Directed Energy Deposition (DED)
  2. Binder Jetting
  3. Powder Bed Fusion
  4. Fused Deposition Modelling
  5. Stereolithography
  6. Material Jetting
  7. Sheet Lamination
  8. Vat polymerization
  9. Sintering
  10. Electron Beam Melting

Directed Energy Deposition (DED)

The clue is in the name of this one. A directed source of energy such as a laser or an electron beam deposits the material on a surface. Said material melts onto the surface with a nozzle on a multi-axis arm. It can move in many directions, allowing for requisite deposition.

The material deposited at first is either a wire or powder, each possessing distinct benefits. While the wire provides increased efficiency of material usage, the powder leads to enhanced accuracy in printing.

Binder Jetting

Binder jetting has a distinguishing feature, marking it up as a highly prominent technology. It is the use of a liquid binder over a layer of printed powder acting as an adhesive. An inkjet nozzle spreads an initial coat of powder on the bed, not dissimilar to one found in a 2D printer.
Binder Jetting (Image Courtesy: Binder Jetting Process by
FM1418
Licensed under CC BY-SA 4.0)

Binder jetting has a distinguishing feature, marking it up as a highly prominent technology. It is the use of a liquid binder over a layer of printed powder acting as an adhesive. An inkjet nozzle spreads an initial coat of powder on the bed, not dissimilar to one found in a 2D printer. It hovers over the bed, depositing the binding agent to bind the particles together, forming one layer of additive manufacturing. This process repeats until the desired 3D structure is complete, after which pressurized air blasts away the excess powder.

Powder Bed Fusion

Powder bed fusion comprises a variety of intricate AM technologies. Direct Metal Laser Melting (DMLM), Direct Metal Laser Sintering (DMLS), Electron Beam Melting (EBM), and Selective Laser Sintering (SLS) make the roster.
Powder Bed Fusion (Image Courtesy: Schematic of selective laser melting by Materialgeeza Licensed under CC BY-SA 3.0)

Powder bed fusion comprises a variety of intricate AM technologies. Direct Metal Laser Melting (DMLM), Direct Metal Laser Sintering (DMLS), Electron Beam Melting (EBM), and Selective Laser Sintering (SLS) make the roster. The general premise is that concentrated heat, i.e. electron beams or lasers, melts the fine layers of material on a powder bed.

Fused Deposition Modelling

Fused Deposition Modelling or FDM is one of the most popular AM processes. Here extruded spooled polymers draw through a heated nozzle mounted on a mobile arm. The melted material builds layer by layer as the nozzle moves across while the bed moves upwards. Chemical bonding agents provide thorough adhesion between layers aided by precise temperature controls.

Typically, the fiber strands are cut very short to make them printable. This causes the material to lose some of its potential strength from cross adjoining layers. Continuous Fiber 3D printing, a variation of the FDM process, uses a spool of fiber instead of many shorter strands embedded in the material while printing. This provides a substantial increase in the tensile strength and stiffness of the printed material due to the long strands of fiber layered on top of one another in a resin.

Fused Deposition Modelling or FDM is one of the most popular AM processes. Here extruded spooled polymers draw through a heated nozzle mounted on a mobile arm. The melted material builds layer by layer as the nozzle moves across while the bed moves upwards.
(Image Courtesy: 3D Printer Liquefier or 3D Printer Extruder by
Priybrat
Licensed under CC BY-SA 3.0)

Stereolithography

Stereolithography uses an ultraviolet laser aimed at a liquid thermoset resin surface. It is comparable to vat polymerization technology.
Stereolithography (Image Courtesy: Stereolithography apparatus schematic by Materialgeeza Licensed Under CC BY-SA 3.0)

Stereolithography uses an ultraviolet laser aimed at a liquid thermoset resin surface. It is comparable to vat polymerization technology. Stereolithography is also well renowned for its tremendous accuracy. Thus, it can produce torque-resistant parts capable of withstanding extreme temperatures.

Material Jetting

Material Jetting is perhaps the closest additive manufacturing technology to its 2D printing contemporary. The printing material is deposited onto the surface using either a continuous or Drop on Demand (DOD) approach.

A directed nozzle moves across the build surface across the x and y axes. The layers are allowed to cool and harden using Ultraviolet (UV) light.

Sheet Lamination

Two distinctive technologies make up the Sheet Lamination enterprise. They are ultrasonic additive manufacturing (UAM) and laminated object manufacturing (LOM). UAM is a low-energy, low-temperature process that uses ultrasonic welding to join consecutive thin metal sheets. Metals like titanium, stainless steel, and aluminum are prominent.

On the other side, LOM employs alternate layers of paper and adhesive instead of welding. Most often used for visual, aesthetic models instead of sturdy structural ones.

Sheet Lamination Overview
Sheet Lamination Overview

Vat Polymerization

Vat polymerization operates in a process called photopolymerization. It turns liquids into solids by exposing the liquid polymers to ultraviolet (UV) light. The 3D design projects UV light onto a vat of liquid polymers, layer by layer. Draining and exposure to UV light repeats until the design is complete, when the vat is drained, leaving the desired 3D solid behind.

Sintering

Sintering is forming a solid material aided by heat or pressure. But it works without melting it to the point of liquefaction. It is a step advanced from traditional photocopying where the toner melts to form an image on paper.

Direct Metal Laser Sintering or DMLS, is a direct offshoot of sintering. It sinters every successive layer of powdered metal to fuse the particles. After each layer, the build platform moves downwards. This allows the re-coater blade to shift across and deposit the next layer. This process repeats until the manufacture of the desired object is complete.

Electron Beam Melting

Electron Beam Melting
Electron Beam Melting

Electron beam melting or EBM is a contemporary of laser melting. It makes use of a concentrated electron beam to melt the layer of metal powder on the build platform. Again, after every next layer, the platform moves downwards to deposit the next layer.

Materials used in Additive Manufacturing

It is more or less possible to use any material in the additive manufacturing processes. But there are a few that lend themselves to be ideal for a high final finishing and quality.

Advantages of Additive Manufacturing

Additive manufacturing has some enormous advantages over traditional manufacturing methods, such as:

  1. Streamlined production: More than anything, AM has reduced the need for multiple complex single-purpose machines because of singular, multi-purpose 3D printing machines.
  2. Less energy, lesser waste: Elimination of conventional manufacturing processes like milling, sawing, mould-creating, etc. have not only brought down the amount of excess raw materials required but also cut down significantly on the energy requirements of a production plant.
  3. Save time, and effort: Additive manufacturing’s design-driven process has allowed on-the-go alterations to be made much more efficiently, saving precious amounts of time and energy.
  4. Update the outdated: Thanks to the highly individualized applications of additive manufacturing, it has become much easier to replace or update any old, outdated parts of a machine. All while more and more advanced resolutions are discovered with the passage of time.

Applications of Additive Manufacturing

Aerospace

Additive manufacturing has found a major player in the aerospace industry. From aircraft wings to helicopter blades, it has helped save plenty of time, money, and energy.

The growing advancements in technology and improving quality standardizations mean that a 100% carbon fiber aircraft may not be an element of science fiction for long
3D printed aircraft parts (Image Courtesy: Maquette d’un LEAP CFM International by KGG1951 Licensed under CC BY-SA 3.0)

In the aerospace industry, it bodes well to remember one simple tidbit. For anything that has to fly, any reduction in its weight can be a blessing in plain sight. And it hasn’t taken aircraft manufacturers long to jump on this technology, which promises to create components like printed carbon fiber parts that possess a higher tensile strength than steel, while at the same time being significantly lighter.

Although larger parts like exoskeletons of aircraft are not quite suitable yet, the growing advancements in technology and improving quality standardizations mean that a 100% carbon fiber aircraft may not be an element of science fiction for long

Healthcare

Applications in the healthcare industry are blossoming with advancements in technology. Often an obstacle with surgical implants or prosthetics is how highly individualized each situation pertains to be. Every new bone graft to be added needs to be of a specific shape, and it can be quite tedious having to saw and mill the additional material to shape the graft, while nearly impossible to have ready-made molds for every occasion.

3D printing has enabled surgeons to print grafts precisely for every individual scenario, and in the process eliminated expensive new moulds while saving precious time.
3D printed bone implants (Image Courtesy: 3D printed skull by Department of Engineering, University of Cambridge Licensed Under CC BY 2.0)

3D printing has enabled surgeons to print grafts precisely for every individual scenario, and in the process eliminated expensive new molds while saving precious time.

The growing promise of the fabrication of synthetic organs is another area to monitor. Niches such as dental restorations have also found advancements by this individualized production process.

Automotive

Automotive Industry
Automotive Industry

The automotive sector is another one that is beginning to realize the vast potential of additive manufacturing. Just as with things that fly, things that move along the ground could do with weight-reducing alternatives.

Carbon fiber is at the pole position of this revolution. Car companies like BMW and Volkswagen are actively pursuing advancements in this sector, with the latter reportedly aiming to manufacture over 100,000 parts using additive manufacturing.

With AM, car manufacturers have found a potentially era-defining technology that has helped them streamline prototyping, production, and manufacture of high-end vehicles, reducing the overall assembly cost by simplifying the process flow.

Conclusion:

The flexibility of additive manufacturing is being more and more realized with every passing day.

To sum it up, additive manufacturing is essentially building stacks of material on top of each other in a design-driven, digital process. For your every potential manufacturing need, there is likely an additive manufacturing solution with its wide range of technologies like:

  1. Directed Energy Deposition (DED)
  2. Binder Jetting
  3. Powder Bed Fusion
  4. Fused Deposition Modelling
  5. Stereolithography
  6. Material Jetting
  7. Sheet Lamination
  8. Vat polymerization
  9. Sintering
  10. Electron Beam Melting

If you are looking for an alternative production process for your dream start-up. If you are a part of aerospace, healthcare, automotive, food-processing, waste-management, or chocolate-making, or even if you are a visual artist, visit our website fabheads for all-things additive manufacturing, and add priceless tangible value to the venture of your dreams.

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