Additive Manufacturing (AM), often referred to as 3D printing, is a revolutionary approach to production that has been transforming industries worldwide. Unlike traditional manufacturing methods that subtract or carve out material from a larger block, AM adds material layer by layer to create intricate and detailed designs. This method offers unparalleled flexibility and precision, enabling the creation of structures and components that were previously deemed impossible or too complex to produce.
The Essence of Additive Manufacturing
At its core, AM is about building objects one layer at a time. This is achieved by depositing material, whether it’s plastic, metal, ceramic, or even biological matter, based on a digital 3D model. Each layer is a thinly-sliced cross-section of the final object.
There are several techniques within the AM domain, each with its unique approach:
The 7 Categories of Additive Manufacturing:
While the term “3D Printing” is often used to describe all Additive Manufacturing processes, there are distinct individual processes that differ based on the material and machine technology used. In 2010, the American Society for Testing and Materials (ASTM) group “ASTM F42 – Additive Manufacturing” established standards that classify Additive Manufacturing processes into 7 categories:
- VAT Photopolymerisation: This process uses a vat of liquid photopolymer resin to construct the model layer by layer.
- Material Jetting: Objects are created similarly to a two-dimensional ink jet printer. Material is jetted onto a build platform using either a continuous or Drop on Demand (DOD) approach.
- Binder Jetting: This process utilizes two materials; a powder-based material and a binder. The binder is typically liquid, and the build material is in powder form. A print head deposits alternating layers of the build and binding materials.
- Material Extrusion: Fuse deposition modelling (FDM) is a common method in this category. Material is drawn through a nozzle, heated, and then deposited layer by layer.
- Powder Bed Fusion: This category includes techniques like Direct metal laser sintering (DMLS), Electron beam melting (EBM), Selective heat sintering (SHS), Selective laser melting (SLM), and Selective laser sintering (SLS).
- Sheet Lamination: Processes in this category include ultrasonic additive manufacturing (UAM) and laminated object manufacturing (LOM). The Ultrasonic Additive Manufacturing process uses metal sheets or ribbons bound together using ultrasonic welding.
- Directed Energy Deposition: This category covers terms like ‘Laser engineered net shaping, directed light fabrication, direct metal deposition, and 3D laser cladding’. It’s a more intricate printing process often used to repair or add material to existing components.
Among the various techniques in Additive Manufacturing, powder fusion stands out as the most commonly method.
Why is AM a Game-Changer?
The capabilities of AM extend far beyond just creating objects. It’s about redefining how we approach design and production:
Complexity & Customization: AM allows for the production of parts with intricate internal geometries. This not only leads to weight and material savings but also enables the creation of customized parts tailored to specific needs.
Sustainability: With AM, material is added only where needed, leading to reduced waste. This is especially crucial when working with expensive or rare materials.
Speed: Prototyping has become significantly faster with AM. Designers and engineers can now move from a concept to a physical prototype in a matter of hours.
While AM started primarily as a tool for rapid prototyping, its applications have expanded dramatically. Today, industries ranging from aerospace to healthcare are harnessing the power of AM for end-use parts, custom implants, and even fashion and art.
For instance, in the aerospace sector, the ability to produce lightweight components can lead to significant fuel savings. In the medical field, surgeons can use AM to produce custom implants tailored to a patient’s anatomy, ensuring better fit and functionality.
Additive Manufacturing is not just a trend; it’s a paradigm shift in how we conceive, design, and produce. As we continue to explore its vast potential, it’s evident that AM will play a pivotal role in shaping the future of manufacturing and design.