METAL ADDITIVE MANUFACTURING

by Bhargav Panchal

Introduction to Additive Manufacturing and its History

Reference: https://www.3dnatives.com

Additive manufacturing (AM), commonly known as 3D Printing, is a technique used for creating three-dimensional parts layer by layer from a metal-based or polymer material. The process works by sending a digital data file to a machine, which then produces the component. Traditional techniques of making parts by machining, cutting, turning, shaping, milling, and other "subtractive" manufacturing processes can be augmented, and in some cases, replaced by additive manufacturing.

AM was founded in 1987 and gradually developed since then, with even greater leaps and bounds in recent years. Since its commercial introduction in the late 20th century, additive manufacturing has revolutionized the industrial business. Metal AM and multiple applications of the process are rising to the forefront of manufacturing as additive technologies take the industry by storm.

It helps make lighter, more complicated designs that would be difficult or expensive to make with standard manufacturing methods. AM has several advantages for rapid prototyping and manufacturing since it eliminates the need for molds, milling, and machining.

Metal Additive Manufacturing Techniques

Although the media likes to use the phrase "3D Printing" to refer to any Additive Production techniques, several distinct procedures differ in their layer manufacturing method. Each process is unique depending on the material and machine technologies employed. As a result, Additive Manufacturing processes are divided into seven distinct categories.

• Binder Jetting
• Directed Energy Deposition (DED)
• Material Extrusion
• Powder Bed Fusion (PBF)
• Sheet Lamination
• Material Jetting
• Vat Photopolymerization
  

Out of these seven processes, mainly DED, Material Extrusion, and PBF are widely used.

1. Directed Energy Deposition (DED)

Reference: https://www.beam-machines.com

DED produces 3D parts by melting and depositing powder- or wire-based materials using a focused thermal energy source such as an electron-beam, plasma arc, or laser. Although the technique may produce metal, ceramic, and polymer components, it is mainly utilized for metal parts and hybrid manufacturing. The substrate bed can be moved to generate complicated designs. DED is also known as laser metal deposition (LMD), 3D laser cladding, or direct light manufacturing. Finally, it is mainly utilized to repair or recondition existing pieces by adding material where needed.

2. Material Extrusion

Reference: https://www.lboro.ac.uk

Material Extrusion is the most popular AM process regarding general consumer demand and quality availability. To make 3D components, it uses a continuous filament of thermoplastic or composite material. In the form of plastic filament, the material is fed via an extruding nozzle, heated, and then deposited layer by layer onto the build platform.

3. Powder Bed Fusion (PBF)

Reference: https://www.3dnatives.com

Laser fused, electron beam fused, fused with agent and energy, and thermally fused are the four types of energy sources employed in PBF. The part is created by melting plastic or metal powder particles, solidifying and fusing in a pattern. The powder bed fusion process uses the build chamber, powder chamber, and coating roller. The coating roller rolls and spreads the powder material across the build chamber to deposit a thin layer of powder to produce the item. The energy source next melts the deposited top layer of the metal powder base. When the layer has been scanned and fused, the build platform is gradually lowered. At the same time, the powder chamber is gradually raised, and the procedure is repeated until object completion.

Conclusion

As AM machines become more affordable for machine shops, the flexibility in design and material properties provides many practical applications and uses.

AM enables the production of customized parts with complex geometries and minimal waste. The digital approach is ideal for rapid prototyping because it allows for quick and efficient design changes during the manufacturing process. Unlike more typical subtractive manufacturing techniques, AM has reduced lead times while reducing material waste. Furthermore, sections that formerly required numerous pieces to assemble can now be manufactured as a single entity, resulting in increased strength and durability. AM can also make one-of-a-kind items or replacement components for no more extended manufactured parts.

Additive manufacturing has advantages in the aerospace, automotive, and medical industries. The ability to repair parts, quick prototyping and low volume production are reasons for the emergence of this sort of manufacturing.

Bhargav Panchal

2020A4PS1862P