Gaining knowledge of 'what is additive manufacturing' is crucial for manufacturing business owners. It's a computer-controlled method of 3D printing that deposits materials, typically in layers, to produce three-dimensional things. It's also known as additive layer manufacturing (ALM).
Having understood what is additive manufacturing, let's understand how it works.
How Does Additive Manufacturing Work?
Additive manufacturing (AM) leverages computing technology to create plastic models directly from a computer and has gained popularity for this ability. Since then, the phrase '3D printing' has gained popularity, even though the method has fundamentally altered, particularly concerning using raw metal materials.
Components are produced in layers using AM. Several approaches might be utilized, depending on the application. Every time, metal powder and a digital, three-dimensional design that the 'printer' can understand and use serve as the foundation.
Types of Additive Manufacturing
1. Binder Jetting
One of the most prevalent forms of additive manufacturing is binder jetting, also known as material jetting or inkjet powder printing.
This technology produces three-dimensional items, which is the sole factor that sets it apart from your typical office printer. Instead of shooting ink onto a sheet, binder jetting propels glue into a powdery substance. The print head rotates vertically and horizontally with each pass, adding a new layer of building material.
2. Directed Energy Deposition (DED)
Three-dimensional objects are made using directed energy deposition (DED) welding principles. A focused energy source, such as a laser or electron beam, melts the substance, commonly a metal wire or powder. After precisely pouring the liquid material onto the build platform, it swiftly solidifies and forms a layer. Until the object is finished printing, this procedure is repeated.
3. Material Extrusion
Material extrusion serves similar purposes to a hot glue gun. When a coil of material is fed into the printer, it is heated until it melts at the nozzle's tip.
Material extrusion has limits while being the most affordable additive manufacturing technique. You can only use plastic polymers since the heating components lack the strength to melt high-density materials like metal, making them unsuitable for applications like tooling and fixturing.
4. Powder Bed Fusion (PBF)
The process of powder bed fusion, also known as electron beam melting (EBM), begins with a sizable bed of material that has been powdered, usually composed of sand, metal, plastic, or ceramic powders.
PBF produces items with a high degree of complexity, making them more durable than those made by some other additive manufacturing methods. With this method, it can get challenging to keep the workplace tidy because a bed of powder is needed.
5. Sheet lamination
A form of additive manufacturing called sheet lamination, also known as ultrasonic additive manufacturing (UAM) or laminated object manufacture (LOM), involves stacking thin sheets of material and joining them via ultrasonic welding, bonding, or brazing.
6. Vat Polymerization
Like powder bed fusion, vat polymerization uses a vat or tank of photopolymer resin hardened in layers by an ultraviolet laser rather than a powder bed. As one layer is finished, another layer is constructed by adding more wax. The process is repeated until the item is complete.
7. Material Jetting
Material jetting builds objects by layering materials, much like binder jetting. Material streaming, on the other hand, melts wax-like materials and accurately deposits droplets onto the build platform instead of building adhesive over a bed of powder. While layers are added, items contain the shape of layers themselves.
Additive Manufacturing Processes
Although these additive manufacturing techniques employ 3D parts with different additive manufacturing process flow, they all essentially follow the same principle of additive manufacturing to produce the finished product.
Step for making a 3D model
The designer initially creates a 3D model of the object that will be printed using computer-aided design (CAD) software or a 3D object scanner. Since the part is a replica of the 3D model, it must be correct in every detail and have its external geometry adequately defined.
Even though additive manufacturing (AM) can print complex parts, the product designer must follow certain guidelines and restrictions to achieve the best results. The design manuals change depending on the type of additive manufacturing technique and material choice. Manufacturers of machinery and companies that offer services with additive manufacturing have substantial design manuals.
Step for making an STL file
When the designer is satisfied, the user changes the CAD file to standard tessellation language (STL). STL is a format for AM that 3D Systems created in the late 1980s for use in their Stereolithography (SLA) machines.
Any model can be saved as an STL file in most CAD programs, including SolidWorks, Inventor, and Catia. Yet, all printer producers offer software that can convert any CAD format into an STL file.
Transfer of STL files phase
Afterward, the STL file is sent to the printer, frequently with the help of specialized machine software, where the model will be adjusted to align for printing.
Equipment setup
Setting up a new printing job involves different steps and prerequisites for each additive manufacturing technology and its variants. The setup includes material selection, printer orientation, temperature control, support structure, and build platform leveling. Also, it entails inserting consumables like binders and print media into the machine. The machine software subsequently converts the STL file's data into G-code. G-code instructions tell actuators, such as motors, where to go, how fast to go, and which direction to go.
Building in part
Once the build has begun, the design is gradually constructed one layer at a time. An intermediate layer has a thickness of about 0.1 mm, although it can be as thin as 20 microns, depending on the technology and material.
Step after processing
Almost all additive manufacturing processes call for post-processing in some capacity. Depending on the AM technology employed and the part's intended function, it might range from straightforward cleaning and polishing to part machining and heating treatment. Lastly, it may be necessary to perform post-processing, such as cleaning, polishing, and painting.
Additive Manufacturing Technologies
Some people still link AM to prototyping. However, this is no longer true. Several standard procedures now have tools that can be produced via 3D printing. Moreover, manufacturers will benefit by learning about additive manufacturing examples before getting into full-scale production. Three categories can be used to classify AM technologies broadly.
The first is sintering, which involves heating the material without liquifying it to produce intricate, high-resolution shapes. Whereas selective laser sintering employs a laser to make the particles of thermoplastic powder stick together, direct metal laser sintering uses metal powder.
The second AM technology completely melts the materials, and this comprises electron beam melting and direct laser metal sintering, which both employ lasers to melt layers of metal powder.
Stereolithography, is the third type of technology employing a method called photopolymerization. In this method, ceramics are produced under high temperatures by blasting ultraviolet laser into a vat of photopolymer resin supported by torque resistance.
The Advantages and Disadvantages of Additive Manufacturing
Advantages of Additive Manufacturing:
Here is the list of benefits of additive manufacturing:
- AM can print intricate 3D geometries with interior features without using any tools.
- Less waste than with machining.
- A part can be produced directly from a 3D model without a sketch.
- Making prototypes more quickly enables designers to test various variations, hastening the design cycle phase.
- For smaller batches, no or less tooling is required compared to conventional machining.
- Printing of production tools is possible.
- Various materials can be combined to produce a special alloy during printing.
- The same alloy may be used in multiple ways in different parts.
Disadvantages of Additive manufacturing:
Here is the list of disadvantages of additive manufacturing
- The construction procedure is slow and expensive because the technology is still developing.
- High equipment costs are the cause of high manufacturing costs.
- Different post-processing tasks are necessary depending on the type of additive manufacturing used.
- The construction volume is small compared to other manufacturing part sizes, such as sand casting.
- Because of poor mechanical characteristics, post-processing is required.
- The surface smoothness and texture could be better than manufacturing techniques like computer numerical control (CNC) and investment casting.
- Compared to manufacturing techniques like CNC machining, investment casting, and die casting, the strength of the products is noticeably lower.
Issues With Additive Manufacturing
The challenges of additive manufacturing are also numerous. The cost of additive manufacturing equipment can reach hundreds of thousands of dollars, and it takes longer to use them to produce substantial lot sizes than conventional manufacturing.
Also, many additively made items need post-processing, such as cleaning and smoothing off sharp edges. Experts say that ensuring your end product has good qualities is one of the most challenging problems. It presents additive manufacturing with its most incredible material science difficulty. How can the potential number of flaws be decreased?
Metals are not the only materials that can have flaws when made additively. Because additive manufacturing is still relatively new, researchers are attempting to comprehend its various components, the interactions between the materials, and the best ways to reduce the possibility of finished goods' flaws.
Additive Manufacturing vs Rapid Prototyping vs 3D Printing
According to our common impression, those working in an industrial or manufacturing environment favor additive manufacturing since it seems more professional. In contrast, the term '3D printing' is preferred by the media and hobbyists. Since less expensive desktop printers gained popularity, 3D printing has been used more frequently.
Rapid prototyping is not the same as additive manufacturing or 3D printing, and creating a prototype model from a CAD file is known as rapid prototyping. Thus, rapid prototyping is the outcome, while 3D printing or additive manufacturing is the method. Rapid prototyping is one of the many additive manufacturing and 3D printing uses.
What Materials Can Be Used in Additive Manufacturing?
With procedures like machining, the amount of material is known. A part initially exists as a block of material, forging, or casting. Although it undergoes machining, its inherent material properties remain unchanged.
Yet, in additive manufacturing, the part's shape is established simultaneously with the material properties. This presents opportunities as well as additional obstacles that are specific to additive. It is feasible to deliberately and accurately regulate the material's properties in particular parts by introducing attributes like porosity, stiffness, or flexibility when the material's properties are determined alongside the geometry.
Polymers, ceramics, and metals are the three materials that can be utilized in additive manufacturing. Although polymers are more frequently employed than other materials, all AM procedures allow for using these materials, even though some additive techniques encourage using particular materials over others. Materials are frequently manufactured as wire feedstock or in powder form.
Additional materials include polymer or adhesive sheets for LOM, paper, adhesive papers, and chocolate. Materials like composites and sand can also be used in AM. The final quality will mostly depend on the material. Printing any material using a layer-by-layer technique is possible, and high temperatures and pressures can alter a material's microstructure.
The Potential of Additive Manufacturing Technologies
The production of innovative bulk-form materials with intended compositions, microstructures, and characteristics has a bright future thanks to AM techniques. Yet, the unpredictable and uncontrollable character of the production of phases and microstructures in an AM method remains a substantial obstacle due to the extensive nonequilibrium nature of laser processing and the intricate mutual interaction of material and process parameters.
Hope you have gained an in-depth idea of what is additive manufacturing, its techniques, and how it works. To lay a solid theoretical framework for AM processes, it is essential to identify the underlying physical and chemical metallurgical mechanisms that affect microstructural and mechanical characteristics. TranZact is a modern, cloud-based business automation software that integrates diverse functions within a manufacturing business, making it easier to manage and monitor complex business processes and scale better.
FAQs on Additive Manufacturing
1. What is additive manufacturing?
Additive Manufacturing (AM), also known as 3D printing, is a manufacturing process that builds objects layer by layer using digital 3D models as a blueprint. Instead of subtractive manufacturing, where the material is removed from a block or sheet of material, additive manufacturing adds material to build the final product.
2. What sector employs additive manufacturing?
Several industries, including aerospace, dental, medical, and automotive, can benefit from innovations, process improvements, and increased agility provided by additive manufacturing. The versatility of 3D printers allows them to create complex or unique objects.
3. What is an example of additive manufacturing?
Additive manufacturing is used in various ways by operators in the industrial sector. For instance, 3D printing is used by companies that produce medical devices to create high-variation products like dental implants.
