In the last few years, metal 3D printing has become increasingly popular. And rightly so: each material offers a unique combination of practical and aesthetic properties to suit a variety of products, be it prototypes, miniatures, jewelry, functional parts or even kitchenware.
The reason metal 3D printing is so hot is that parts can be serially 3D printed for mass production. In fact, some parts created with metal 3D printing are already just as good, if not better, than those manufactured by traditional methods.
In traditional manufacturing, making metal and plastic objects can be a wasteful process. Plenty of chunky parts are produced and surplus material used. When aircraft makers manufacture metal parts, up to 90% of the material is cut away. 3D printing metal parts uses less energy and reduces waste to a minimum. And finished 3D printed products can be up to 60% lighter than their machined counterparts. The aviation industry alone saves billions of dollars through this weight reduction, mainly due to fuel.
So, what do you have to know about metal 3D printing? Here’s more:
Before we get into the basics of metal 3D printing, let’s take a glance at the latest innovations in this expansive field. Over the past couple of years, a number on new players have emerged, transforming the landscape of the traditional metal 3D printer.
Although metal 3D printing is not quite at the consumer level, the technology has taken many strides. What once was confined to industrial-sized and expensive machines is now becoming accessible to small-to-medium businesses. Here are the latest companies that are disrupting the traditional metal 3D printer:
The Massachusetts-based 3D printing startup Desktop Metal is perhaps the biggest game-changer in the metal 3D printing market. Last year, the company unveiled two metal 3D printers; the Studio System and Production System. This groundbreaking hardware tandem is making metal additive manufacturing much more affordable and capable of producing parts faster.
The Studio System is a desktop-sized metal 3D printer that uses the patented Bound Metal Deposition (BMD) extrusion process. Similar to FDM 3D printing, this metal 3D printer utilizes MIM metal powders that are bound by a polymer mix. Once 3D printing is complete, the objects are placed in Desktop Metal’s furnace at a temperature of up to 1,400 degrees Celsius, melting away the polymer and leaving you with a metal part. The Studio System, along with the furnace and cloud-based software, costs around $120,000.
On the other hand, the industrial-sized Production System uses a process called single pass jetting. The 3D printer works by depositing metal powder, followed by a binding agent. The machine is equipped with over 32,000 jets that are capable of spraying millions of droplets per second. The Production System also uses the furnace for post-processing, and costs around $360,000 (furnace not included).
While these two metal 3D printers are surely too expensive for the average consumer, the cost is a fraction of traditional metal 3D printing systems, which can easily run you over $800,000. It’s clear that big-name companies believe in Desktop Metal’s mission, as the startup has received major funding from the likes of BMW, Google, Lowe’s, and others.
On the smaller side of the spectrum, the metal 3D printing company Digital Metal, a subsidiary of the Swedish metal powder producer Höganäs, recently revealed the world’s first-ever high-precision binder jetting system for small metal objects.
The metal 3D printer, dubbed the DM P2500, produces exceptionally small and intricate metal components. Digital Metal’s machine includes a print volume of 2500 cm3, and also prints with 42 µm layers at 100 cc/hr. This metal 3D printer offers an incredible resolution of 35µm, and eliminates the need for support structures.
The Swedish metal 3D printing company is currently pushing its product on the commercial market, and is working with Honeywell Aerospace, the French institute and technological innovation hub Centre Technique des Industries Mécaniques (CETIM), and an undisclosed leader in fashion design.
Markforged is another 3D printing company that is focusing on making this once inaccessible technology more open to the masses. The Markforged Metal X is a metal 3D printer that offers an end-to-end manufacturing solution. The company states that its metal 3D printer is ten times less expensive than alternative metal 3D printing systems.
The Metal X offers a build size of 250 x 220 x 200, and a layer height of 50 microns. Similar to Desktop Metal’s Studio System, this metal 3D printer works by printing metal powder that is bound in a plastic matrix. On the company’s website, Markforged showcases the different types of metal parts that can be 3D printed, and also how much businesses can save by utilizing its metal 3D printing. Learn more about the Metal X here.
How can you 3D print metal at home? As extremely high temperatures are needed for metal 3D printing, you can’t use a regular FDM 3D printer.
Simply put, there’s no way you’re gonna 3D print pure metal at home in this decade. Dedicated metal 3D printers for the home probably won’t be around until at least 2020. However, as nanotechnology evolves, we might see a substantial growth in new applications. Like conductive 3D printable silver that can be ink-jetted using a system very similar to the 2D printer you have at home. Even mixing different materials, like plastics and metals into the same object, will be possible.
Even if you can’t 3D print metal objects at home, you can still resort to plastic filament with added metal powders. ColorFabb, ProtoPasta or TreeD Filaments offer interesting composite metal-PLA filaments. These are filaments that contain a significant percentage of metal powders but provide enough plastic to be printed at low temperature (200 to 300 degree Celsius) with just about any 3D printer. At the same time, they contain enough metal to have the look, feel and weight of a metallic object. The iron-based filaments even form rust in certain conditions.
In composition, metal 3D printer filament is typically 50 percent metal powder. Meanwhile, Dutch 3D printer filament company Formfutura claims they have ramped up the ratio to 85 percent metal powder and 15 percent PLA. These metal 3D printer filaments are called MetalFil Ancient Bronze and MetalFil Classic Copper. You can even print them at “moderate” temperatures of 190 to 200 degree Celsius.
Given that metal 3D printing is usually more difficult, you may want to upgrade your 3D printer nozzle, especially if you are using a beginner machine. Metal 3D printer filament tends to wear nozzles quickly. Durable printer hotends (E3D’s V6 Hotend, for example), which are themselves made from metal, are able to withstand high temperatures and can be mounted on most 3D printers. Just be prepared to replace them more often, as metal 3D printer filament can be very abrasive.
Also, you should be aware you’ll probably need a proper finishing process (brushing, sand grinding, greasing, waxing or coating) of your metal 3D printing creation to make it really “shine”. Here are some examples:
What if you want better results or even full metal 3D prints? Should you buy a metal 3D printer for your business? We wouldn’t advise it unless you want to do metal 3D printing every day. The price for such a machine is high: a professional metal 3D printer from EOS or Stratasys will set your business back by up to $500,000. And apart from the initial payment, you’ll need people to operate and maintain the machine as well as finalize prints (i.e. polishing).
Simply put, there’s no such thing as an affordable metal 3D printer.
Unless you want to start a 3D printing metal business and you need a professional part 3D printed in metal, you’re better off using a 3D printing service to suit your needs. Companies like Shapeways, Sculpteo, and i.materialise offer purely metal 3D printed parts.
If you’re a goldsmith, you can also order wax models for casting special metals.
Speaking of wax models, most 3D printed metals (including gold and silver) are actually produced through a process called lost wax casting. That is, not everything is 3D printed in factory. Services often turn to other companies that are specialized in metal production to finish the order. Nevertheless, the number of metal 3D printing services is growing rapidly all over the world. And at the same time, metal 3D printers are becoming more common at 3D printing services.
The reason big companies like metal 3D printing so much is that it can be used to build “topologically optimized” parts. This makes it possible to perfectly distribute the material in a component in order to make it thicker only where it needs to withstand more stresses, thus drastically reducing the weight without sacrificing structural integrity. However, this is not the only technology out there. Some are significantly more affordable and more accessible.
Please be aware that metal 3D printing requires special CAD designs. For general information, Shapeways offers metal 3D printing guidelines. For even more advanced information, take a look at this article from Statasys, which discusses metal 3D printers and the nuances of metal 3D printing.
Here are some examples of 3D printing metal prices of the common Benchy test model:
As you might expect, the prices for solid metal 3D printing go way up.
What do engineers and designers have to know about metal 3D printing? First of all, there are three different metal 3D printing methods you should know about.
You can find more on the metal 3D printing technologies here.
There are some common misconceptions when it comes to 3D metal printing.
With that said, the benefits of metal 3D printing are great.
Worldwide, more than 100 companies offer their services to 3D print metal objects. The following are the most popular metal 3D printing services for consumer use.
If you want to dig deeper, check out All3DP’s 3D Printing Service Guide 2018 - 34 Best 3D Printing Services.
Shapeways, the world’s most popular online 3D printing service, offers two services. As a consumer, you choose from a broad range of professionally designed items, customize them and have them printed to your specifications. Similar to other 3D printing services, Shapeways offers storefronts to designers who can then sell and print their work. Shapeways is also suitable for rapid prototyping. Customers benefit from industrial grade printers (EOS, 3D Systems) and dedicated technical support.
3D Printing Metals: Aluminum, brass, bronze, gold, platinum, steel, silver, and precious plated metals. Also available is castable wax for jewelers.
Note: Shapeways can also be accessed via All3DP’s Best Price 3D Printing Service, where prices can be compared to Sculpteo and i.materialise in real-time.
Like Shapeways and i.materialise, Sculpteo is an online 3D printing service that allows anyone to upload 3D models and have them fabricated in a wide variety of materials. In keeping with its competitors, Sculpteo also allows individuals and professionals to open up an online storefront and sell their designs to the public. Sculpteo’s stable of printers includes high-end machines from 3D Systems, EOS, Stratasys, and ZCorp. Its extensive technical documentation will help you detect design flaws and choose the right material for your project.
3D Printing Metals: Alumide (plastic with aluminum particles), brass, silver.
Note: Sculpteo can also be accessed via All3DP’s 3D Printing Price Comparison Service, where prices can be compared to Shapeways and i.materialise in real-time.
i.materialise is a company that works with industries to produce prototypes and 3D printed products. But for the general public and individual designers, i.materialise offers an online 3D printing service called i.materialise. Like Shapeways, the online 3D printing service allows anyone to upload their 3D designs and have them printed out. Once an object has been uploaded and successfully printed, a designer can offer it for sale either via the gallery on the i.materalise online store, or embedded on their website.
3D Printing Metals: Alumide (plastic with aluminum powder), brass, bronze, copper, gold, silver, steel, titanium.
Via 3D Hubs, you can search for individuals and businesses that offer 3D printing services in your area, upload your STL file for an instant estimate, and connect with them directly to get the job done. This online 3D printing service also allows you to filter by materials, by user rating, by distance, and multiple other factors. Regardless of the type of item you want to have printed, there’s likely someone in your vicinity who can print it for you. A considerable number of materials can be printed in industrial quality, marked as “HD” in the search field.
3D Printing Metals: Aluminum, bronze, cobalt chromium, stainless steel, titanium.
Some industrial sectors already use metal 3D printers for everyday objects – ones you may not even know are 3D printed.
Before metal 3D printing can really take off, some hurdles will need to be overcome. Primarily it’s the high cost, which can’t be scaled down through molds. Additionally, the low speed of production is problematic for metal 3D printing.
The main issues with metal 3D printing are the same as with any 3D printer: software and hardware limitations, material optimization and multi-materiality.
Although we won’t focus too much on software here, it is worth mentioning that the largest publishers, like Autodesk, SolidWorks and solidThinking, are all working on products to support as much as possible metal 3D printing processes.
In general, 3D printed metal parts can be as strong as traditionally manufactured metal components. The parts created with DMLS have mechanical properties equivalent to a cast metal part. Also, the porosity of an object made by a good metal 3D printer can reach 99.5% density. In fact, manufacturer Stratasys claims 3D printed metals are above industry standards for density testing.
3D printed metal is available in several resolutions. At its highest resolution, the layer thickness is 0.0008” – 0.0012” and the X/Y resolution is 0.012” – 0.016”. The minimum hole diameter is 0.035” – 0.045”.
Direct metal laser sintering (DMLS), also known as selective laser sintering (SLS) and selective laser melting (SLM), is the metal 3D printing process that most large companies are taking into consideration today. It works in the following way: An energy source (a laser or another energy beam) fuses an “atomized” powder (perfectly round, tiny, spherical particles) to create layers of an object.
More than ten major metal 3D printer producers in the world use this technology in their machines, with even more entering the market. Most are located in Germany.
You might think that the only 3D printing process “missing” from metal 3D printing is fused filament deposition but that is not entirely true. And while you can’t really fuse metal filament on your desktop, very large industrial metal manufacturers can. And do. There are two ways to go about “depositing metal”.
One is called Directed energy deposition (DED) or laser metal deposition (LMD). A laser beam fuses metal powder as it is slowly released and deposited to form the layers of an object by an industrial robotic arm. Although the process is usually executed inside a closed chamber, a recent MX3D project implemented a similar approach to 3D print a full-size bridge.
The other deposition technology is called Electron Beam Additive Manufacturing (EBAM), a type of soldering process, where a very powerful electron beam is used to fuse a 3 mm thick titanium wire and the molten metal is shaped into very large metal structures. However, unless you work for the Department of Defense, you are unlikely to run into this technology.
Another professional approach that uses a power bed is “binder jetting”. In this case, layers are formed by gluing together the metal particles and later sintering (or melting) them together in a high-temperature kiln, just like you would do for ceramics.
One other possibility, which is also similar to ceramics-based crafts, is to mix the metal powder into a metal paste. Using a pneumatic extrusion 3D printer (like a syringe bioprinter or a low-cost food printer) to form the 3D objects. Once you’ve 3D printed the desired shape, the objects are once again sintered in a kiln.
This approach is used by Mini Metal Maker, possibly the only truly affordable metal 3D printer out there.
Pure titanium (Ti64 or TiAl4V) is one of the most commonly used materials in metal 3D printing, thanks to its versatility, strength, and lightness. It’s used both in powder bed fusion and binder jetting processes, mainly in the medical industry (to make personalized prosthetics) and the aerospace/automotive/tooling industries (to make parts and prototypes). The only catch? It’s highly reactive, which means it can easily explode when in powder form. That’s why it needs to be 3D printed in a vacuum or in an argon gas atmosphere.
Stainless steel is one of the most affordable materials in metal 3D printing. It’s very strong and can be used in a wide variety of industrial and even artistic/design applications. This type of steel alloy, which also contains cobalt and nickel, is particularly hard to break while at the same time having very high elastic properties. It is used almost exclusively for industrial applications.
Inconel is a superalloy produced by a company called Special Metals Corporation. It is composed primarily of nickel and chrome and has a high temperature resistance. For that reason, it’s used mainly for applications in oil, chemical and aerospace industries (for airplane black boxes).
Due to its lightness and versatility, aluminum is now a very popular metal for 3D printing applications. It is used primarily in a variety of aluminum-based alloys.
This metal alloy has a very high specific strength. (That’s strength divided by density, which basically indicates the force required per unit area). It’s most commonly used to produce turbines, dental implants, and orthopedic implants — all areas where metal 3D printing is becoming the preferred manufacturing method.
A few exceptions aside, copper and bronze are mostly used in lost wax casting processes and not so much in DMLS. That’s because they’re not ideal for industrial applications and are more commonly used in arts and crafts. ColorFabb offers both metals as a base for its special metal 3D printer filaments.
Iron — even magnetic iron — is also exclusively 3D printed as an additive to PLA-based metal filaments, such as the ones produced by ProtoPasta and TreeD.
Most powder bed fusion companies can 3D print with precious metals such as gold, silver and platinum. The challenge here, along with maintaining the material’s aesthetic properties, is to make sure that the precious powder management is optimized. Precious metals are 3D printed both for jewelry, medical and electronics applications.
Rest assured, a metal 3D printer will strain your budget, costing you at least $100,000. Here’s a variety of metal 3D printers, some of which you can find at 3D printing services.
If you had to 3D print really large metal structures, your best metal 3D printer choice would be Sciaky’s EBAM technology. It’s capable of offering just about any size of machine built on demand. This metal 3D printer is used mainly for the US aerospace and defense industries.
Sciaky’s largest regularly available system is the EBAM 300. It has a build size envelope measuring 228” (5791 mm) width x 48” (1219 mm) depth x 48” (1219 mm) height.
The company claims that the EBAM 300 is also one of the fastest industrial metal 3D printers commercially available. This metal 3D printer can produce a 10-foot-long titanium aircraft structure in 48 hours at a rate of approximately 15 lbs. of metal per hour. In general, forgings that used to take 6-12 months to complete can be completed in 2 days with this metal 3D printer.
Sciaky’s unique technology uses a high power electron beam gun to melt a 3 mm thick titanium filament, with standard deposition rates ranging from 7 to 20 lbs per hour.
Another way to 3D print large metal parts is with Fabrisonic’s Ultrasound Additive Manufacturing Technology (UAM). Fabrisonic’s production machines are three-axis CNC mills, which have an added welding head for additive manufacturing.
In this metal 3D printer, the metal layers are first cut and then welded together using ultrasound. Fabrisonic’s largest 3D printer, the 7200, has a build volume of 6″ x 6″ x 3″ (2 x 2 x 1.5 meters).
The German company, which is one of the primary 3D printer suppliers of huge aerospace companies such as Airbus, has recently introduced a new metal 3D printer, the Xline 2000.
The 2000 has two lasers and an even larger build volume of 800 x 400 x 500 mm. This metal 3D printer, which uses Concept Laser’s LaserCUSING (a type of selective laser melting) technology, can 3D print objects in alloys of steel, aluminum, nickel, titanium, precious metals, and even some pure materials (titanium and high-end steel.)
License: The text of "Metal 3D Printer Guide 2018 – All About Metal 3D Printing" by All3DP is licensed under a Creative Commons Attribution 4.0 International License.
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