Additive Manufacturing(AM), or 3D printing, is a process used to create a physical (or 3D) object by layering materials Layer upon Layer based on a digital model. Additive Manufacturing technologies can produce complex geometries without the need for expensive tooling. Additive manufacturing can encompass multiple processes, depending on the hardware, material, and principle of working. Additive Manufacturing is used in many industries, including Automotive, Architecture, Fashion, Medical, Aviation, Space, and consumer goods. Some of the popular Additive Manufacturing (AM) processes are Fused Deposition Modeling (FDM), Stereolithography (SLA), Selective Laser Sintering (SLS), and Powder Bed Fusion (PBF). These AM processes build up layers of material to create a final object, with each process using different materials and methods to do so.
Even though Additive Manufacturing has been in existence since the 1980s. Initially, it was mainly used for prototyping. However, with recent technological advancements, Additive Manufacturing has become easily accessible. This has led to an increase in its use for producing end-use parts in a wide range of industries ranging from construction to medical. Furthermore, new materials specifically designed for AM are being developed, allowing for new designs and applications. As technology continues to evolve, it is anticipated that AM will become more widespread and have a transformative impact on many industries.
Here are the 3 general steps in the Additive Manufacturing process:
Designing and preparing the 3D model
Printing the object layer by layer
Finishing & Inspection of the product
We have already seen that Additive Manufacturing or 3D printing, is a process that converts digital inputs, such as computer-aided design files, into tangible objects that may be the end product. To export a file suitable for 3D printing, a user Starts with a digital CAD file and then needs to create an STL (Standard Tessellation Language), The STL file is used to plan the build and to generate support.. The slicer software then imports the STL file and translates it into a layer file. The machine parameters are assigned to this layer file. Layer by Layer, the build platform continues to add successive layers, fusing them together with heat, chemical reactions, or other bonding methods, depending on the material used. The process continues until the object is complete. Post-processing may be required after the object is printed to achieve the desired surface finish or texture, such as cleaning, sanding, or painting. Different types of AM technology use different materials and methods, such as Fused Deposition Modeling (FDM), which melts and extrudes thermoplastic filament, and Stereolithography (SLA), which uses a laser to solidify liquid photopolymer resin layer by layer. Despite these differences, all AM processes follow the fundamental principle of building up objects layer by layer.
There are several basic types of Additive Manufacturing. A few of the widely used ones are listed below:
Vat Photopolymerization creates 3D objects by selectively curing liquid resin through targeted light-activated polymerization. Stereolithography (SLA), Digital Light Processing (DLP) and Scan, Spin & Selectively Photocure (3SP) are a few sub-sets of this technology.
Material Extrusion is a popular Additive Manufacturing technique that involves the layer-by-layer deposition of materials to create three-dimensional objects. Also known as fused filament fabrication (FFF) or fused deposition modeling (FDM), material extrusion utilizes a filament or wire-like material, typically thermoplastics, that is melted and then extruded through a nozzle. The molten material is carefully deposited onto a build platform, where it solidifies to form the desired shape. This process is repeated layer by layer until the entire object is created. Material extrusion is widely used due to its simplicity, cost-effectiveness, and versatility in producing functional prototypes, complex geometries, and end-use parts in various industries.
Material Jettingalso called drop-on-demand or photopolymer jetting, is an Additive Manufacturing technique that uses inkjet printheads to deposit liquid materials. The materials are jetted onto a build platform or previous layers and then rapidly solidified through curing methods like UV light or heat. Material jetting allows for high-resolution printing, intricate details, and smooth surface finishes. It enables the use of multiple materials or colors in a single print job and finds applications in industries requiring precise details and customization, such as product design, jewelry, dental, and healthcare.
In Binder Jetting a binding agent is selectively deposited to bind the powder material to form a 3D part. Binder jetting can be used to print various materials, including metals, sands, and ceramics. The process is most suitable for high-volume and complex components.
Powder Bed Fusion is an Additive Manufacturing process that involves melting and fusing powder to create 3D objects. There are several variations of Powder Bed Fusion, each with its own unique characteristics.
Direct Energy Depositioninvolves adding or fusing material onto an existing part or creating a new one using powder or metal wire and an energy source. There are variations in this process as well, such as
Sheet Laminationinvolves fusing layers of material such as paper,plastic or metal together to create parts. Ultrasonic Additive Manufacturing and Laminated Object Manufacturing (LOM) are the variations in this form of 3d additive manufacturing.
There are several materials that can be utilized in Additive Manufacturing. The primary material categories used in 3D printing are polymers, metals, and composites. Polymers are a frequently used material in 3D printing, including thermoplastics (such as polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS)), high-performance materials (like polyetheretherketone (PEEK) and polyetherketoneketone (PEKK)), nylons, and thermoplastic polyurethane (TPU). The commonly 3D printed metals are aluminum, titanium, stainless steel, Inconel, and cobalt chrome. Composites that combine different materials are also increasingly used in 3D printing. Additionally, biocompatible materials, such as hydrogels and biodegradable polymers, can be utilized in Additive Manufacturing to produce personalized medical devices and implants.
The applications of Additive Manufacturing technologies are rapidly expanding. Here are some of the sectors currently using Additive Manufacturing:
Additive Manufacturing offers the aerospace industry the ability to create intricate, lightweight components, streamline designs, and improve fuel efficiency. Through AM, rapid prototyping accelerates the pace of aerospace technology advancement.
Additive Manufacturing enhances industrial production by allowing on-demand customization and efficient design modifications. Manufacturers use AM for jigs, fixtures, and tooling, while also 3D printing challenging spare parts, reducing costs and waste
Additive Manufacturing aids the oil and gas sector by crafting complex, durable parts for exploration and production. With AM's use of high-temperature and corrosion-resistant materials, components like valves and impellers last longer. In remote locations, AM boosts efficiency and cuts costs.
Additive Manufacturing in the medical field facilitates the creation of custom implants and devices using body-compatible materials. The technique enables the design of intricate structures, including curves and internal chambers, in medical products.
Additive Manufacturing empowers the athletic sector with customized footwear and sporting gear, optimizing fit and performance. The technique speeds up product development and extends to insoles and accessories, pushing innovation in consumer goods
Additive Manufacturing is pivotal for major engineering firms like Boeing and General Electric, playing a key role in their production processes. Beyond rapid tooling, AM aids in equipment repair and replacements, curbing maintenance costs and extending machinery lifespan.
So far we have seen that, Additive manufacturing, also known as 3D printing, is a revolutionary technology that has transformed manufacturing processes across various industries. Now let us looks at some of the advantages it offers to businesses:
Using Additive manufacturing technologies is cost-effective for small production runs or when parts require customization as it eliminates the need for tools or moulds. Even the cost of entry for AM has consistently been falling with Industrial-quality printers now available at highly affordable rates making the initial capex low.
Additive manufacturing (AM) enables on-demand production of parts, eliminating the need for large inventory stockpiles and reducing inventory costs for companies. This approach allows companies to produce parts when needed, in the exact quantity required, and respond quickly to changes in demand or design without disposing of obsolete inventory. Additionally, 3D printing enables the production of complex or low-volume parts, expanding the range of products and variations offered to customers without maintaining high inventory levels.
The most transformative aspect of additive Manufacturing or industrial 3D printing is its capacity to produce highly intricate and personalized components. It offers greater design flexibility at a reduced cost and in less time than traditional manufacturing techniques. With AM, the constraints of conventional manufacturing methods such as tooling, molding, casting, and subtractive machining are eliminated. This allows designers and engineers to create parts with complex geometries, internal structures, and features that were previously unattainable or challenging to produce using traditional methods. The layer-by-layer construction process of AM provides precise control over material deposition and the ability to create internal structures that are not possible with traditional methods.
Any process is bound to have both pros & cons and 3d Additive Manufacturing is no different. Here are some of its prominent disadvantages:
Currently, there is a limit to the types of materials that can be processed within Metal AM specifications. These are typically pre-alloy materials in a base powder form. This can limit the range of applications for which Additive Manufacturing is suitable.
Compared to traditional manufacturing methods, additive manufacturing is a relatively slower process due to the layer-by-layer construction. This can be particularly time-consuming for larger or more intricate parts. Certain Additive Manufacturing technologies necessitate post-processing procedures like finishing, polishing, or painting to attain the required surface finish and visual appeal. These extra steps can increase the total time taken for the manufacturing process.
A big challenge in additive manufacturing is developing reliable and consistent processes for production, as factors such as temperature, humidity, and material quality can affect the quality of the final product. Standardized testing methods and certifications are still in the nascent stage, which can make ensuring the quality and reliability of AM parts difficult, particularly in industries high-precision industries.
Additive manufacturing is a promising and exciting technology which is expected to continue to evolve and improve, enabling the production of highly complex and customized parts with greater design freedom. Moreover, the incorporation of Additive Manufacturing technologies with other technologies such as artificial intelligence and robotics is anticipated to transform the manufacturing process and open up new opportunities for customization, efficiency, and sustainability. In general, AM is expected to become an increasingly significant component of the manufacturing sector, providing new possibilities for product innovation, supply chain optimization, and sustainability.