With each passing season, processes become more refined and automated. This means that design engineers have to leave room for future innovations and upgrades so their operations can keep up and be more flexible and financially feasible. Under this scenario, additive manufacturing (AM) found its way into the manufacturing industry and shook up the old ways to tackle product design and furnishing. In this piece, I’ll share the basics of AM and how it is retooling the manufacturing world.
Is AM the next big innovation for your plant? Read along and make a decision.
What is additive manufacturing?
You have probably heard about 3D-printed objects. Over the past few years, they have been a fixed feature in popular media outlets, such as Mashable, and blockbusters, including Iron Man 2 and Ocean’s 8. Just to name a few. These cool and functional creations are only possible because of a technology known as additive manufacturing.
Additive manufacturing is the innovative process undergone to complete the industrial production of 3D objects through the subsequent addition of layers of materials. AM differs from conventional manufacturing methods because it does not require machining or other techniques to remove surplus material.
At its heart, additive manufacturing is a processor-controlled technology in which engineering-approved input data from computer-aided design (CAD) files instructs a machine on the steps to complete to manufacture a specified product.
The roots of AM can be traced back to the 1980s and stereolithography. But the first big break came in 2012, when GE Aviation started making their LEAP Fuel Nozzle in large numbers.
By all means, AM is a huge part of industry 4.0 and the IIoT era, enabling enterprise digital transformation. The technology is making a big splash because it enhances rapid prototyping and speeds up production time in industrial sectors, such as automotive, aerospace, and healthcare.
Big industries like BMW updated operations to leave room for AM, seeing a positive outlook on performance.
After this intro, I recommend that fellow engineers look at ISO/ASTM 52921-13 (2019) for expanded details on AM (standard terminologies, coordinate systems, and testing methodologies).
Additive manufacturing vs. 3D printing: How are they different?
People often mix up the process of 3D printing with additive manufacturing and vice versa. For that reason, it is worthy to touch the ground at the root of this confusion. Check out this level 1 comparison and see how they fare against each other.
|3D Printing||Additive Manufacturing|
|Objects come to life through material addition in a layer-by-layer approach.
CAD software instructs the printer on the amount of material to deposit and the location.
Mainly works with polymeric materials. Limited applications for metals and alloys.
The lead process technology is Fused Deposition Modeling (FDM).
Has a mechanism for rapid prototyping and finished product manufacturing.
|Objects become tangible through material addition, not necessarily layer-by-layer.
CAD software and a printing machine work together to manufacture products.
Works with ceramics, polymers, and metals. Thereby, it is well suited for industry use.
The principal process technologies are FDM, Powder Bed Fusion (PBF), and Material Jetting (MT).
It is also good for quick prototyping and product manufacturing.
The comparison allows me to see why AM is often confused with 3D printing. However, when carefully analyzing the differences in printing style, materials, and available technologies, it makes sense to place 3D printing as a technology servicing additive manufacturing. And not the other way around! For AM, the technology encompasses a broader scope of solutions and applications targeted at the same purpose:
- new production parts;
- assembling fixtures;
- legacy spare parts;
- topology optimization and generative design.
For the engineering field, AM is a high-performing digital resource at the service of engineers. It empowers them to become more visual and hands-on with their designs and R&D tasks. Whereas 3D printing is a way to gain a physical copy of their work for further review, polishing, and processing.
Types of additive manufacturing
Additive manufacturing is categorized into seven types. Each one plays a role in the latest advancements in materials and applications.
- VAT photopolymerization
As was mentioned earlier, AM derives from stereolithography (also called VAT photopolymerization). So, it’s only fair we address it first!
This process deploys a VAT of liquid photopolymer resin and a laser beam. The latter draws a shape in the resin to create a layer. Motor-controlled mirrors direct the UV light to cure the layer.
VAT photopolymerization is of great use in several industries. It is vastly used in the healthcare industry, where it helps build hearing aids, facial prosthetics, dental care, and surgical learning tools.
- Material extrusion
Material extrusion is often used for low-scale models, cheap prototypes, or at-home applications. The method involves pulling a polymeric material (in the form of a filament) through a heated nozzle in a moving header. Throughout the application, the material deposits in a continuous stream that forwards layer creation. Since the material is heated (melted), each new addition is able to fuse with the previous layer seamlessly. The bonding is controlled by temperature and chemical agents. FDM is the additive process of excellence for material extrusion.
- Material jetting
MJ is one of the fastest and most precise additive processes. This technology is based on the selective deposition of a mixture of photopolymer materials in droplets over a platform.
Layers are created in a single pass. Further curing and solidification are both achieved under UV lights.
Material jetting is ideal for producing realistic models and prototypes.
- Binder jetting
This additive process utilizes a binder and powder-based materials. The powder is applied with a roller. Afterward, the print head deposits the binder atop the built platform. Following the first application, the product is lowered, so the process can restart again to create a new layer. The binder’s role is to bond layers together, usually in liquid form.
Many experts consider binder jetting to be among the fastest AM methods. The process is suitable for various materials such as metals, polymers, and ceramics. The binder-powder ratio leaves room for product customization.
Binder jetting found deployment across several industries. Several contributions have been made to the manufacturing processes of dental and medical pieces and aerospace parts. When it was used to build structural components, results weren’t quite as favorable, though.
- Powder bed fusion
In PBF, powder particles melt by means of a heating source, laser, or electron beam. Subsequently, superimposed molten layers adhere to form parts. There are four variants to the powder bed fusion process:
- Selective laser melting (SLM)
- Selective laser sintering (SLS)
- Electron beam melting (EBM)
- Direct Metal Laser Sintering (DMLS).
There has been good PBF acceptance in the aviation sector, as well as other industries. The technology is suited for different materials, such as metals and polymers. Though it is not the fastest of additive processes, its results in the making of structural pieces are well accepted. Hence, it is often used for prototypes and visual models.
- Direct energy deposition
One of the more complex AM processes to date is direct energy deposition (DED). It requires a four to five axis arm to move around melted material, so it can be deposited in a fixed object.
DED is better suited for repair purposes. It provides high precision in material additions to existing components. Metals, ceramics, polymers, or wires are commonly used compatible materials. Their melting process is carried out with a laser or an electron beam. Final products support many industries, including aerospace, energy, military, and healthcare.
- Sheet lamination
Just as the name suggests. Sheet lamination (SL) is the additive manufacturing process where sheets of material bind together to form a 3D object.
Binding techniques depend on the material. Metal sheets require ultrasonic welding. Fiber-based material and ceramics demand thermal energy (e.g., from an oven) to join the layers. There are seven variants to SL:
- Laminated Object Manufacturing (LOM)
- Selective Lamination Composite Object Manufacturing (SLCOM)
- Plastic Sheet Lamination (PSL)
- Computer-Aided Manufacturing of Laminated Engineering Materials (CAM-LEM)
- Selective Deposition Lamination (SDL)
- Composite Based Additive Manufacturing (CBAM)
- Ultrasonic Additive Manufacturing (UAM).
Sheet lamination is a low-cost and speedy method. At times, it can require post-processing to fine-tune the pieces. The applications serve several industries. For instance, paper-based techniques found a place in full-color prints. Metal-based sheet lamination has a purpose in hybrid manufacturing. Overall, applications in prototyping are frequent.
For more in-depth information on the types of AM, check out ISO/ASTM 52900:2015.
Applications of additive manufacturing
Additive manufacturing has emerged as a powerful enabler of the manufacturing industry. A joint report by TCT magazine and Altair highlights how this technology came through during the COVID-19 crisis, assisting in the manufacturing of PPE items (desktop machinery), nasopharyngeal swabs (VAT photopolymerization), and final parts for ventilators (3D printing). Through it all, AM proved to be a driving force that helped get around the manufacturing and logistical bottlenecks that come with the production of long-lead items, ultimately offering a fitting solution to reduce tooling costs through the adoption of alternative processes.
The same report was a valuable source for finding encouraging results in industrial applications. Case and point:
- Bowman International switched to AM, adopting HP’s Jet Fusion) to produce bespoke ‘Roller Train’ cages made out of PA-11 (polyamide) to boast interlocking structures. Since then, Bowman increased the parts’ work life up to 500% (compared to the traditional counterparts) and improved 70% the load-bearing capacity.
- K3D (a division of the Kaak Group) built an industrial robot dough cutting knife in stainless steel 316L. The robot is used in the hospitality industry to cut 8,000 dough pieces per hour. K3D saved around 90% of its weight by using the Metalfab1 technology, thanks to a 20 to 1 part consolidation. A 60% reduction in lead time and cost was also achieved.
BMW is an AM pioneer in the automotive industry. They switched to 3D printing for part manufacturing, most famously with the i8 Roadster. About the switch, Dr. Jens Ertel, Director of the BMW Group AM Campus, shared that “the use of components made by additive manufacturing in series production of vehicles is increasing particularly strongly,” referring to the general landscape. Moreover, he addressed the company’s intent to forward AM through “technology scouting and evaluating innovative production systems.”
Lockheed Martin also uses AM for part manufacturing. They recently installed a Velo3D Sapphire metal 3D printing system at their Additive Design & Manufacturing Center. Their goal is to expand the application in their space program, enhancing traceability and layer-by-layer accounting to preserve design intent.
Benefits of additive manufacturing
There’s so much to be said about the benefits of additive manufacturing. I credit the technology for opening a window to accelerate prototyping, topology optimization, and generative design, saving time and money. Additionally:
- Engineers get a chance to look at their design with new eyes from an early stage and work on improvements directly over 3D physical objects, overcoming unforeseen and previous limitations.
- CAD files can be turned into tangible pieces in a matter of hours. Before AM, teams and enterprises had to wait for weeks to months before seeing their design come to life.
- Manufacturing processes are less energy-consuming and take less space. Big machines and complex systems with large feedstock and inventory are replaced by a 3D printer with lower energy and space demands.
- Direct synchronization between the work done in simulations, CAD files, and the final results takes place.
Challenges in deployment of additive manufacturing
So far, the AM industry has had good effects on engineering, manufacturing, and logistics. Yet, there are also weak spots that require visitation.
To that end, I particularly identify two critical issues that must be addressed before massification:
- Certification. Material, part, and process certifications are pressing challenges for the AM industry. Investing efforts to match or mimic the quality assurance of legacy production methods is something that demands utter priority. A starting point is to tailor developments catering to specific industries and products. Otherwise, continuing a one-size-fits-all approach will run its course soon. Even more, in those sectors that need long-lasting reliability certifications before and after installation.
- Human workforce. The other issue worth examining is how massification impacts the workforce. I expect the expansion of AM to cut jobs and human dependency to complete specific tasks. However, new opportunities will open in other areas, such as machine programming and maintenance. To do just that, defining the roles of future professionals (technicians and engineers) and focalized training are essential to undermining red flags and making a seamless transition.
Just like any solidified industry, AM can only benefit from standardization. It will help it reach hard-to-reach sectors and warrant the safety of applications. On the other hand, for companies to maximize the advantages of an additive process, they must up their teams’ disposition and skills. If those ingredients align, massification should be an undeniable success on both ends.
If you want to know more about additive manufacturing or need consulting, reach out to Verdusco today!
We look forward to helping you solve today’s problems with tomorrow’s technologies!
Message me at:
- Email: Raul@VerduscoConsulting.com
- Phone number: 248-622-2850.