'Tis the season of giving, so we at 3Diligent are excited to share what is hopefully a very useful gift.
As you know, 3Diligent works with hundreds of manufacturers around the world, representing thousands of machines, hundreds of branded manufacturing processes, and dozens of manufacturing brands. This covers a wide breadth of machine processes and even wider breadth of different materials. Some of these are more obscure. Others are better known. But all of them contribute to the global ecosystem of manufacturing.
For this reason, we are sharing an open source tool with the community for the searching of materials and machines in the digital manufacturing sphere!
The Technology Search Tool captures many of the different hardware options for the processing of digital manufacturing files. At the current moment, roughly 900 different branded technologies are captured in the database. Using our search bar, you can use your own search terms and phrases to identify the right solution. Additionally, there are some very useful filters to aid your search for the right technology; looking into the different listed technologies will give you a more detailed view.
With the Material Search Tool, we likewise capture the wide variety of materials in the market. Again, there are nearly 1,000 different materials captured in the database. With the power of the search bar, you can look for specific keywords of significance to you or leverage the filter functionality where appropriate.
Beta Stage and Open To Feedback
It should be noted that we are sharing this tool on a limited basis with our mailing list, and not announcing it for broader release. It is in beta state, and as you will see, there are certain functionalities that are still in progress. With that being said, our desire is to make this tool as comprehensive as possible for the community. So, if you don't see a particular material or technology that should be represented, or record that needs a tweak we want to know! You can simply click the green button for consultation and provide a message and links to relevant information there. Or if you're a material or equipment manufacturer seeking to make a bulk upload, email us and we'll send you a bulk upload spreadsheet.
More to Come
This is the first of many exciting announcements we looks forward to sharing with you over the next few months. So please keep your eyes peeled, join our mailing list if you haven't already, and have a very happy holiday season!
As you probably know, Fabtech is one of the nation’s largest manufacturing equipment shows and a week worth circling on the calendar every year. More than 48,000 attend and 1,700 companies exhibit to show off the latest in metal manufacturing.
Given 3Diligent’s commitment to always live on the leading edge of manufacturing technologies, we will be there too and we’d love to connect with you while there. There are multiple ways to meet up with us both at and outside the show…
First, given 3Diligent’s broad range of available metal 3D Printing technologies, we’ve been honored with a speaking slot to share our perspective on metal additive with attendees. At 2:30 on Monday in Room S403A, I’ll be on stage to discuss advancements in metal 3D Printing, the applications that are increasingly leveraging metal additive technologies, and a specific case study involving one of our metal additive projects – aluminum 3D printed nodes for the Rainier Square Tower in Seattle. Here are the details if you’re interested in attending.
Also, back by popular demand, we’ll be hosting discussions on top of the city after the trade show closes on Monday and Tuesday at the Metropolitan Club on the 67th floor of the Willis Tower. In these 30 minute meetings, we’d love to reconnect with you to discuss future opportunities and also share some forthcoming enhancements to our software and service. So if you’d like to see what’s coming soon and offer early feedback, it’s a great opportunity to do so. We’ll be hosting discussions from 5:00—7:30 P.M. on Monday and Tuesday.
Whether you’d like to chat at the show or schedule a meeting time on Monday or Tuesday evening, just email email@example.com and we’ll firm up a time to visit!
Not all that long ago we posted a blog about ways that urethane/silicone casting is better than injection molding. While that was certainly true for a significant number of circumstances, there is no doubt that injection molding is the better choice over casting for a substantial number of cases as well. In this post we will examine when those scenarios exist and summarize the ways that injection molding is better than casting.
Injection Molding Delivers a Lower Part Price
Injection molding can deliver more cost-effective part prices than can casting. This is probably the single most relevant input in the decision between the two processes. As production volume increases, so does the value of an automated process that injects and ejects material, respectively, to and from a molding tool. In contrast, casting is inherently manual in nature and the scale economies for urethane casting are not as significant. As a result, the per-part cost of an injection-molded item can be quite low — on the order of pennies or dollars when operating at high volumes — in contrast to casting's per-part cost that can be on the order of 5 to 50 times higher.
Injection Molding Utilizes a Wider Material Set
Another key benefit of injection molding is the wide variety of different materials, as long as they are offered in a pellet form. Even certain resins can be injection molded using the reaction injection molding process. Hence, the breadth of choices for resin and plastic injection molding is far broader than those available to casting; which creates a significant number of potential advantages related to material properties. While advances in polyurethane have enabled flame-retardant material and a wide variety of shore values, the range of casting options still pales in comparison to injection molding.
Injection Molding is Faster at High Quantities
Similar to its pricing benefits, injection molding can deliver significant speed gains at scale. The process of injection molding a part can take on the order of seconds to minutes. In contrast, the underlying process for each cast part can take on the order of minutes to hours. So while the amount of time required to set up for an injection mold may be significantly higher than it is for a cast part, the speed with which each individual part is created means that there is a crossover point where production of a volume of goods will be faster in molding versus casting. Since injection molding tools can take a couple of weeks or longer to set up, this crossover point typically occurs after the production of several 100 to several 1000 parts.
Injection Molding Has a Longer Tool Life
Another key benefit of injection molding over casting is the life of the molding tool. These tools are typically built out of aluminum, stainless, or tool steel. These durable metals can sometimes maintain their form over the course of millions of shots. In contrast, casting tools are far less durable. Silicone and resin can degrade after several dozen to several 100 uses. As a result, they are typically disposable items and those seeking to leverage recurring use of casting molds will want to arrange some kind of maintenance or production plan in advance.
So as we've seen here today there are a wide variety of ways in which injection molding is superior to casting, Just as there are a number of ways that casting is superior to injection molding. Which camp does your program fall into? At 3Diligent, we are happy to offer both technologies so we would encourage you to sign up and submit an RFQ today.
As the calendar turns to autumn, the trade show circuit kicks back into gear. With it, 3Diligent has two speaking events within two days on tap next week. Hopefully, you can catch us Monday in Colorado Springs or Tuesday in Long Beach. Reach out if you're planning to be at either show and would like to meet up. We'll get it on the books!
It's well documented that injection molding offers highly cost-effective options for large volumes of parts. But what about when you only need a few dozen or a few hundred parts for your application? In relatively low volume circumstances, urethane casting can be a much better way to go. Since the cost of tooling involved with creating a mold for silicone or urethane casting is so much lower than engineering and constructing an aluminum or steel injection molding tool, you can typically bring your first few dozen or hundred units to market at a fraction of the cost. This in turn provides you with strategic flexibility when it comes to products that may not have high enough market demand to justify an expensive tool. This circumstance might exist when you're bringing a product to market and unsure of how fast it will fly off the shelves, or when annual demand has been established as relatively small, and casting nets out to a lower cost than building and maintaining an injection molding tool.
Castings can be turned around at a much faster rate for the first several parts than can injection molding. With urethane and silicone castings, the creation of a tool can be done in a matter of hours or days. This is especially true of urethane cast parts, where the tool is typically constructed by putting a "pattern" part into a container and surrounding it with the mold material, which proceeds to set around the object (the object is removed after curing to create the void into which urethane is poured for your part. Creating resin tools is often done by 3D printing them, which may take days at most, but still quite quick. The actual part creation process is moderately fast, as the silicone or urethane may require hours to set once poured into the mold. In contrast, the creation of an injection molding tool is a significant mental exercise as well as a physical one. This means both mold creation time and labor components are higher than they are for casting molds. The higher labor component also contributes to overseas production of injection molding tools, which also an increase in shipping time for parts. For these reasons, urethane casting can deliver much faster turnarounds so long as quantities are relatively small.
With urethane casting you have a higher degree of design flexibility than you do with injection molds. For starters, injection molding requires consideration of a draft angle throughout the design. In brief, surfaces of an injection molded part need to have a slight angle to them so that they can be readily ejected by the injection molding tool. In contrast, urethane cast parts can have straight lines because the nature of the process does not require a draft angle. Because the mold itself is flexible and mold release agent can be applied to it, parts can be removed from the casting mold without the same issues you encounter with a metal tool. This also means that undercut features can be incorporated into cast parts in a way that isn't plausible for injection molding. Additionally, having a consistent wall thickness ratio throughout your part is less relevant to urethane casting than it is to injection molding. Due to the heat involved in the injection molding process, careful attention to heat transfer must be considered when designing the part. If very thin walls are connected to to thick ones, the likelihood of warpage due to heat transfer that take the part out of its tolerance range is a real threat. In contrast, the urethane casting process is not impacted significantly by heat, mitigating this concern.
While sometimes overlooked due to injection molding's popularity for scale production, urethane and silicone casting can provide an extremely valuable solution to businesses bringing products to market or sustaining production of low volume parts. By mitigating the up-front costs of bringing production parts to market, it can provide a level of strategic flexibility and cost savings if the circumstances of your program are right. Additionally, the speed with which new casting molds and parts can be fabricated can provide you great strategic flexibility to test different designs before scaling production. Lastly, the design flexibility that casting grants you can be powerful in delivering you the exact part design you want. For all these reasons, urethane and silicone casting may be a great solution for you.
We are very excited to announce that 3Diligent was recently honored as one of the most promising Industry 4.0 startups of 2019 by Startup City Magazine. The award followed the decision of a distinguished panel comprising of analysts, CEOs, CIOs, VCs, and the Editorial Board of Startup City. We are, naturally, extremely proud of the recognition as it comes on the heels of exciting progress for our digital manufacturing company and the hard work of our team.
Check out this extract from the article and give the whole thing a read if you have a minute!
Achieving success in the Industry 4.0 era requires companies to embrace an unprecedented rate of change. New machines and materials are announced with breathtaking frequency. Additive manufacturing technologies are perhaps the poster child of this next Industrial Revolution. It plays a central role in the promise of Industry 4.0 through its ability to produce extraordinarily complex products with effectively zero tooling costs. This means next generation products can be developed for enhanced performance and mass customized in a quick, economical manner.
With all of these shifting dynamics, the high rates of obsolescence tied to these emerging technologies and the opportunity to create true competitive advantage by navigating this path successfully, the stakes are high when it comes to digital manufacturing decisions. Naturally, the path isn't without its fair share of dead ends and wrong turns. Buying machines can be a costly option fraught with obsolescence risk. Sourcing externally doesn't provide an easy solution either, as even the biggest job shops are limited in the number of machines and materials they can bring to bear.
Aiming to mitigate these complex industry challenges, 3Diligent offers a different approach to deliver a one-stop-shop to its customers. Like Amazon or Airbnb, it has network qualified manufacturers around the world with the complete range of machines and materials manufacturers seek. For customers with custom parts they seek to have quoted, they need only submit a simple request for quotation(RFQ) on its secure portal at www.3diligent.com. 3Diligent takes care of the rest by leveraging its proprietary software to assess, price, and fulfill orders.
Both 3D Printing and CNC Machining are driven by CAD files. As a result, generating tool paths can be largely automated for both processes. That being said, 3D Printing excels at creating organic geometries — curved surfaces, high degrees of complexity, and similar builds. CNC machines generally struggle with gently arcing surfaces, requiring extra time and tool changes to deliver this complexity. On the contrary, due to the additive nature of 3D Printing, the issue of including additional detail during the manufacturing process is almost of no temporal consequence.
3D Printing can uniquely deliver internal features in its build parts. With CNC machines, the tool needs access to the feature to be machined. As a result, the interior areas of CNC parts are filled and solid; hollow only when machining two or more pieces that will be welded together in a post-process. The additive nature of 3D printers, on the contrary, simply skips the vacant areas during the phase of deposition. A notable exception to this rule is the requirement for internal support structures in certain hollow designs.
Another feature that 3D printers can deliver is the lattice structure. These builds are generally impractical to machine and, when they are internal to a part, feasibly impossible. 3D Printing is basically the perfect lattice building technology. Because these processes place materials layer by layer in mostly any location, they're able to build up lattice structures and customize their shape to deliver particular performance characteristics like stiffness, elasticity, or failure modes.
CNC Machining and 3D printing are the two leading technologies when it comes to one-off designs. Both are driven by CAD files and are capable of creating singular parts with relative ease — compared to the tool creation required by casting an injection molding technologies. However, 3D Printing generally gets the nod when it comes to one-off production. While machining generally does not require the creation of tools, there are circumstances when custom fixtures need to be created for a machined part to allow for the machinist to access all relevant features of a design. In contrast with this, 3D Printing is a completely tool-less technology; simply fit in a design and get an output. As noted previously, the output may have supports that require a degree of post-processing effort, but nevertheless, a single unit comes very easily from a 3D Printing process.
Mass Personal Customization
Following on two of the earlier points about organic geometries and one-offs, 3D printers outperform CNC machines in the domain of mass personal customization. There is a strong trend toward providing customers unique opportunities to customize products that meet their very personal needs. This is especially notable in the medical field when we talked about custom orthodontics, teeth aligners, and more. When it comes to these sorts of applications, 3D Printing definitely crushes CNC Machining. Because 3D Printing delivers an extreme variety of different geometries, with limited care to the complexity or geometry at hand, even at quantities of one, it has emerged as a leading tool for mass personal customization. You need only look to the success of Invisalign or Smile Direct Club as examples of 3D Printing's ability to deliver mass personal customization.
A last area where 3D Printing outperforms CNC Machining is in inventory flexibility with regards to raw stock. CNC Machining requires a workpiece from which the design is carved away. This is one reason why blocky shapes tend to be better suited for CNC Machining. You simply need to chip away a little bit of material and you will arrive at your end part. With CNC Machining, however, you need raw stock that is in the shape of your final product to be economically viable. If your part has an extremely high scrap ratio, which is to say that you are carving away a lot of excess material from your starting work piece, the project can become highly uneconomical for your business. As a result, you need to have the right raw stock pieces to deliver CNC parts economically; and if you work with a wide variety of different parts, you need to stock a variety of material options to be efficient with your machine. In contrast, 3D printers are immensely flexible when it comes to their manufacturing process. Generally speaking, 3D printers operate off of filament or powder inputs that are basically one-size-fits-all. A highly condensed container of powder or filament can be delivered and stocked, and that in turn can create basically any geometry.
3D Printing outperforms CNC Machining on a wide variety of applications and use cases. As we touched on today, 3D Printing crushes CNC in many cases, but just as CNC Machining kicks 3D Printing's butt in its own universe of applications. It's all a matter of use and — thankfully at 3Diligent — we are capable of supporting you with whichever path you choose to go down.
How Metal 3D Printing Helped Manufacture Unique Look of Seattle High-Rise has been accepted in the 3D Additive Manufacturing track. Presentation Title: How Metal 3D Printing Helped Manufacture Unique Look of Seattle High-Rise Track: 3D Additive
There has been a lot of hype in the last few years for 3D Printing. This is understandable, given its capabilities of delivering geometries that other technologies cannot, and to do so without external intervention — like fixturing. That being said, 3D Printing is not the be-all, end-all for Digital Manufacturing. In fact, CNC Machining, the longtime-standard for Digital Manufacturing, surpasses 3D Printing in a wide variety of tasks — sometimes even at quantities of one. In this article we will lay out four ways CNC still beats 3D Printing.
Better at Tight Tolerance Parts
CNC Machining is generally better than 3D Printing at creating tight tolerance parts — for a handful of reasons. First, and most notably, CNC Machining's been around longer. That means that precision control has been refined to a point where regularly delivering tolerances of .005" is commonplace; additionally — in the 3Diligent network — certain precision machinists can deliver .0005". In contrast, the 3D Printing processes are all relatively new and, as a result, have not been refined and optimized over as many decades to deliver super tight tolerances. It's worth noting that certain 3D Printers have been built to service micro-scale parts, and these can and do deliver tight tolerances, but that is limited to tiny parts, and more than just an exception for the technology than the norm.
Beyond sheer technological maturity, most in-market 3D Printing processes will struggle to ever achieve tolerances consistently on par with CNC machines because of the thermal nature of the printing process. Typically, 3D printers melt material from one form (e.g., filament, powder) and reconstitute it as another (the final shape). This means rapid heating and cooling, and therefore the possibility of warpage (among other potential microstructural impacts). In contrast, machining takes a hard part and simply chips away at it. All the while, the coordinates of the main work piece don't materially change — in shape or temperature.
Excels with Bulkier Shapes
The second area where CNC Machining outperforms 3D Printing is in bulkier designs. Quite simply, CNC machines are capable of processing a wide variety of stock materials that come in standard shapes (e.g., block, sheet, rod). CNC machines can simply chip away from these shapes and provide you a solid part in short order. 3D printers, by their very nature, additively construct parts. At their very fastest, you're laying down one thin layer of material on top of another. At their slowest, the 3D Printer is basically etching the part geometry one voxel at a time.
To use an analogy, imagine you're tasked with creating a black circle for your niece's grade school art project. You're given some white paper, some black paper, a black pen, and some scissors. What approach would you take? Sure, you could grab the pen, draw a circle, and start filling in the blank. But you could alternatively just grab those scissors and cut your circle out. You'd finish faster. And to the earlier comment, you'd be assured a degree of consistency that might not come if there were slight variances in the way you precisely filled in the circle shape.
In brief — big, blocky shapes do not print fast, but they tend to cut quickly. Additive would better shine on those designs where you'd pick the pen instead of the scissors.
Gives Consistent Material Properties
The next area where CNC outperforms 3D printers is in delivering reliably consistent material properties. To extend our grade school crafts analogy a step further, you may end up with a perfectly black circle if you precisely filled it in with your pen. However, there's also the possibility that the ink didn't flow quite right at a given moment, or you missed a spot ever so slightly because you had a hiccup. In contrast, if you cut the corners off of a piece of paper that you already can see is black, there's not much guess work.
With 3D Printers, you are oftentimes melting material on the fly. Sometimes you're setting a shape with a binding agent and curing that part's material properties in a secondary step — there are a few other ways as well. However, the main takeaway is that additive manufacturing typically establishes the material characteristics of the part on the fly as you reconstitute the matter in the build chamber. In contrast, with machining, you are simply chipping away from a forged piece of material billet. The material properties of that raw stock are already checked and confirmed.
All of this is not to suggest that 3D printers cannot deliver production parts that can meet and exceed the needs of many real-world applications. In fact, 3D printed parts consistently deliver material properties on par with or superior to cast parts, and you likely know that castings are literally EVERYWHERE. But it is to say that there are variables in play with 3D Printing (and casting) that don't exist to the same extent with CNC Machining. Microstructural features (like porosity and grain orientation) matter much more, especially as it relates to parts that experience high cycle fatigue. You may want to consider post-process solutions like Hot Isostatic Pressing.
Offers a Better Material Selection
A fourth way in which CNC Machining still beats 3D Printing is in material selection. It should be noted that 3D Printing is making tremendous strides in this area — and in fact certain materials that cannot be manufactured with any other process are now becoming available to 3D printers. Things like custom alloy powders are being developed just for the powder bed fusion 3D Printing process, for instance, that outperform conventional stock casting or CNC materials. With that being said, machining still currently offers a much wider variety of material options than 3D Printing. Materials like brass, for instance, are machinable and not generally available to the world of Additive Manufacturing. The same holds true in the polymer world. Whereas polyethylene, polypropylene, and acetal (Delrin) are viable options for a capable machinist, printing in those materials is still not heavily commercialized. To the extent that those materials are available in market, it is on a relatively niche basis for specific machines. The tradeoffs of different 3D Printing processes is a discussion for a different day though.
So Is CNC Machining Better Than 3D Printing?
In truth, anybody who tells you machining or 3D Printing is "better" is just offering their own opinion, based on their own applications. But suffice it to say, CNC Machining does currently outperform 3D Printing on a number of dimensions. From delivering tight tolerances right off of the machine, to delivering bulky shapes faster and cheaper, to providing more reliable material properties, to offering a broader range of materials: CNC Machining remains an incredibly useful technology that is driving Industry 4.0 forward.
Powder Bed Fusion and Binder Jetting are two of the most common classes of metal 3D Printing technology. Each one provides unique advantages and considerations as it relates to meeting the needs of different applications. Powder Bed Fusion has grabbed headlines in the industry for the longest, but binder jetting's emergence has grabbed its fair share of headlines as well. Could either process be the solution for one of your applications? Here we provide a quick tale of the tape, comparing these two popular metal 3D Printing process families.
Powder Bed Fusion
Powder Bed Fusion involves the use of a focused energy source - commonly an infrared laser or electron beam - to selectively melt layers of metal powder. This process results in highly dense parts that provide strengths typically surpassing cast parts (and occasionally forged parts).
As its name would suggest, Binder Jetting involves the targeted jetting of a binding agent to hold particles of powdered material together. This process takes place layer-by-layer to produces a "green part," basically a fragile matrix of metal held together with adhesive. This part can then be used for non-stress applications or more commonly undergoes post-processing steps, most notably sintering.
How accurate are these processes? How reliably do they deliver that accuracy? Or said in the most straightforward engineering terms, which tolerances can they hold?
As Low As .001"
Powder Bed Fusion technologies are very accurate, with some technologies capable of achieving tolerances as tight at .001" (25 microns). It should be noted that metal Powder Bed Fusion is generally expected to meet tolerances of .005" +/- .002" per inch, and certain powder bed technologies like Electron Beam Melting have global tolerances that are looser than that. Generally speaking, Powder Bed Fusion is more accurate than Full Sinter Binder Jetting.
Binder Jetting is a relatively accurate 3D Printing technology, but much of its accuracy depends on what level of post-processing you have in mind for your print. Since we are specifically looking at metal 3D Printing, then for the purposes of this discussion we are weighing Full Sinter Binder Jetting and Infiltrated Binder Jetting. Full sinter involves the creation of a green part, but then sintering that part in an oven once the shape is set — which results in roughly 20% shrinkage and creates a challenge in delivering tight tolerances. This is not as noticeable with certain types of geometries and smaller parts. Additionally, this can be improved through repeated manufacturing. Nonetheless, its default tolerances are higher. Infiltrated Binder Jetting doesn't experience the same degree of shrinkage because the metal matrix is filled with another lower-melting-temperature metal instead of allowing the matrix to sinter down on itself. Still, the nod generally goes to powder bed when we talk about accuracy.
How expensive are these processes? Both relative to each other and to more traditional metal manufacturing processes like CNC, Casting, or Metal Injection Molding?
Cost Effective for Intricate Designs
Powder Bed Fusion prints are generally pretty expensive. The underlying energy source - an expensive laser or electron beam - is quite expensive. The powder commonly required for these machines is also more refined than that required for binder jetting, also driving up cost. Generally speaking, Powder Bed Fusion becomes the most cost effective solution when a part has been designed with the process in mind. This means the designer has eliminated unnecessary mass and structured the part to be self-supporting throughout the build.
Lower Cost Inputs = Lower Cost Outputs
By jetting binding agent rather than accurately tracing a path, Binder Jetting can effectively arrive at a geometry much faster than Powder Bed Fusion. While this analogy oversimplifies things (especially for Electron Beam Melting), Binder Jetting is a paint brush to Powder Bed Fusion's pen or pencil. This approach gives Binder Jetting particular usefulness for chunkier parts that still have a good bit of complexity. Augmenting this reduction in machine time, Binder Jetting leans on lower cost solutions to create geometries. Glue and an oven are decidedly cheaper than a fiber laser or electron beam. Additionally, Binder Jetting doesn't require the same fine granulated powders that powder bed systems do — this means cost savings as well.
Which materials can each technology process? Is there a broader range of materials available to one process or the other? How do material options compare to traditional manufacturing technologies?
Selective Due to Economics
Nearly every metal can be used in Powder Bed Fusion systems. Certain powder bed systems are better at processing high temperature materials whereas others are more conducive to lower-melting-temperature materials. Generally driving this is the extent to which the powder bed chamber is heated during manufacturing. Lower temperature chambers can be more prone to cracking and internal stress when processing high temperature materials. More than capability is actually economics when it comes to commonly available materials for Powder Bed Fusion. Materials commonly associated with less critical applications (e.g., iron) are not as prevalent as higher value metals like Titanium, Aluminum, Stainless Steel, Copper, and Nickel Inconel superalloys (e.g., 625, 718).
Limited Due To Nascency
Because the first step of Binder Jetting's process simply involves binding particles of metal together with glue, it offers tremendous material flexibility, in theory.1 Materials such as sand, gypsum, metal, and plastic can be bound with the Binder Jetting process. With regards to the next step — sintering — some limitations emerge. The extreme temperatures required for melting titanium, for instance, are challenging within a sinter furnace. Stainless Steel is the most common material used in the Full Sinter Binder Jetting process, in part because its behavior with regards to shrinkage in the sintering step is perhaps best understood.
Will the process deliver me the density I need for repeated cycles and fatigue?
99.5% and Up
Powder Bed Fusion delivers dense parts. Straight off the machine, density is typically north of 99.5%. This is significantly above the density of cast parts, which typically run around 98% dense. This is one key consideration in how PBF parts can deliver better-than-cast material properties. Additionally, parts can undergo a Hot Isostatic Press (HIP) post-processing step to bring density within a hair of 100%.
The Binder Jetting process generally cannot deliver the same density as Powder Bed Fusion parts. Quite simply, while the sintering process can create density typically on par with cast parts, it does not achieve complete density. This level of density is appropriate for many applications. However, for certain tasks with high cycle time fatigue concerns, this may be a limiting factor. Again, Hot Isostatic Press (HIP) as a post-process step can be used to improve overall density.
Does one process provide unique advantages when it comes to available geometries? Do each operate with the same design constraints?
Master of Complex Lattices
When it comes to design, Powder Bed Fusion offers a great deal of design freedom. Relative to traditional manufacturing processes, powder bed is capable of processing extraordinarily complex designs just as fast - actually faster - than standard blocks of material. Especially with laser systems, very fine features can be achieved. We generally don't recommend features smaller than 1mm, although we commonly can resolve them. In general, this allows for extraordinarily complex lattice structures to eliminate weight while retaining strength. Notable to consider is that Powder Bed Fusion systems generally require the inclusion of supports, made from the same material as the part, to prevent the metal from warping under the rapid heating and cooling that occurs during the process. Certain powder bed platforms operate with a heated chamber which reduces the need for such supports, but that can create other design considerations. Either way, you should try to design your part to be self-supporting. Just imagine if your part was a skyscraper — would any aspect of it need scaffolding to be built? This is critical, because parts designed without supports in mind can drive the price of a part up more than 50%.
Support Needs Reduced, But Sintering Must Be Considered
The Binder Jetting process does not have the same support restrictions as powder bed systems because there isn't a thermal component to creating the green part. With that being said, the post-processing step can be problematic for fine features, as the green part shrinks in size by 15-20%. This can also come with the threat of internal stresses. As a result, binder jetting parts are generally limited to sizes smaller than a fist for cost-effective printing and sintering.
The Bottom Line
It's really a tie. Depending on the part you've designed, the quantities you seek, the material you desire, and the performance you require, either process might carry the day. The good news is that 3Diligent offers both of these 3D printing technologies (any many more!), and our experts can help you design to take advantage of either process.