Metal 3D printing the next Industrial Age

COVID-19 may have served as an inflection point for metal 3D printing. After suffering a short-term downturn in the wake of the pandemic, the global metal additive manufacturing market is expected to grow to US$18.5 billion by 2032, according to business research firm IDTechEx.

The United Kingdom-based market analyst says several factors have come into play to push this burgeoning technology to the foreground, most notably the supply chain disruption caused by the pandemic itself.

The remote and autonomous capabilities of "printing" metal components – oftentimes in locations where shipping was hindered due to lack of personnel or materials – brought to light the ease, flexibility, and efficiency of metal 3D printing for many companies and industries.

While ultimately still unable to compete with traditional manufacturing output, 3D printers of all kinds have seen a robust portfolio of styles and methods, which have led to an incredibly competitive market in only a few short years.

With a widespread grassroots effort from hobbyists and entrepreneurial startups, 3D printers have provided a leg-up for consumers and small-business owners to begin manufacturing on their own. However, to compete with typical manufacturing, larger companies have found that the entry price for a metal 3D printer that could meet their needs is too high and thus not cost-effective.

A silver lining for the additive manufacturing industry is its potential to develop precision parts in nearly any permutation that can be designed by using any 3D designing software. However, this too is generally used in more niche projects.

Nonetheless, the possibilities have already been seen, prompting several companies to begin developing powerful, entry-level printers that could not only match conventional manufacturing but sometimes even surpass it.

Appeal of localized manufacturing

Possibly the largest draw for metal 3D printing is the ability to make components, parts, tools, or prototypes, when and where you need to.

With skyrocketing shipping costs and worker shortages contributing to disturbances in global supply chains, a renewed interest in domestic and localized manufacturing has blossomed to mitigate risks when relying on outsourcing from other countries.

Within this environment, metal additive manufacturing has received possibly the most attention, being a strong contender for low-carbon, clean energy manufacturing.

For metal 3D printers, a power source can be limited to electricity, requiring no burning or superheating of metal for production.

Although 3D metal printing cannot yet compete in the volume of typical metal manufacturing, AM does occupy some space in the green energy field and has been lauded as a space that can facilitate energy uptake.

And while metal 3D printers aren't just limited to printing solid metal parts – solar cells, LEDs, capacitors, circuit boards, microprocessors, and much more – one of the most compelling attributes of 3D printing is the pinpoint accuracy that can be achieved.

Now, it's just a matter of repurposing for efficiency.

While most metal 3D printers will see permanent homes for mass production, mobile manufacturing is perhaps the most potent weapon for this burgeoning technology.

Ever-expanding materials portfolio

Contributing to the refinement of 3D printers are the materials with which can be printed.

One of the major factors that have slowed metal additive manufacturing penetration is the limited menu of metallic materials available for 3D printers. Not only are few relatively high-performance powders readily available for demanding applications, but the cost of metal powders or wire spools often comes with a price tag that exceeds hundreds of dollars per kilogram.

To address this, material startups have been exploring new chemistries and high-performance metals like aluminum and alternative feedstock forms such as pellets or slurries.

Research at the National University of Science and Technology Institute of Steel and Alloy Catalysis Lab has managed to print 3D products from metals of different groups on a single printer, reducing overall costs by an average of 30%.

ExOne, a company that has been making waves with its binder jetting technology, recently developed a metal 3D printer to print precious metals like gold, silver, and platinum.

Additionally, there is a surplus of specialized companies that are beginning to only manufacture proprietary powders, making it in their best interest to bring the cost down and the effectiveness up to catch the numerous companies' attention in providing high-quality prints.

Beyond single element metals, alloys have begun seeing their true worth as 3D printing, and metal powder companies need the final product to be ductile as well as strong. With past metal 3D printing limiting results due to brittleness or tensile strength, many have begun mixing cocktails of powders for the best effect to meet their customer's needs.

ExOne at the forefront

A global leader in industrial sand and metal 3D printers, Pennsylvania-based ExOne's metal 3D production facility has been in continuous operation since 2005.

Widely regarded as the fastest method of metal 3D printing, the binder jetting process employed by ExOne is very similar to inkjet printers – an industrial "inkjet" printhead selectively deposits a binder into a bed of metal powder particles to then create a solid part, one thin layer at a time. Binder jetting can create 3D objects in metal, sand, ceramic, or other 3D material powders.

After metals are printed, the final part must be sintered in a furnace to fuse the particles together into a lightweight, highly dense solid object.

ExOne has often been at the forefront of metal 3D printing, expanding into the copper and precious metals fields with a collaboration with Maxxwell Motors to develop 3D printed copper windings for drive systems in electric vehicles and the Pressburg Mint of Slovakia, purchasing two of the company's 3D metal printers to print gold, silver and platinum coins.

Pressburg Mint of Slovakia hopes to use cutting-edge metal 3D printing technologies to breathe new life into the city's centuries-old tradition of minting coins, while Maxxwell Motors hopes to use ExOne's binder jetting technology to print winding assemblies as a single giant piece, eliminating the need for coil wrapping, bending, tooling, and welding of the individual parts.

Pioneering 3D printing since 1995, ExOne has persisted and managed to bring to today a highly functional and efficient metallic printing process that very well could be the method of large-scale manufacturing of the future.

SPEE3D printing military parts

To showcase the potential for mobile printing, SPEE3D's WarpSPEE3D printer has caught the attention of the militaries of two nations, the United States and Australia. Both having taken great interest in the potential for active conflict on-site parts replacement as well as the benefit of replacing components in practically any remote location.

Founded in 2015, SPEE3D quickly gained traction as a forerunner in metal 3D printing technology.

Rigorously tested in the remote bushlands of Australia, WarpSPEE3D has proven its capabilities with a three-week trip of more than 764 miles (1,200 kilometers) over rough terrain to operate in hot and dusty conditions.

During the trial, the printer produced more than a dozen different replacement parts for an M113 Armored Personnel Carrier, a vehicle that has been used by the Australian Army for over 40 years.

The trial aimed to prove metal 3D printing could produce high-quality, military-grade parts that can be validated and certified for use in the field. For example, one of the parts made was a wheel bearing cover, which is often damaged by underbrush when driving through the bushland. The two-kilogram (4.4 pounds) cover was printed in just 29 minutes at a print cost of around US$100.

The success of this trial clearly demonstrated the importance additive manufacturing would play in military readiness.

More recently, the United States Navy selected SPEE3D to partake in the Navy's MAINTENX exercise to manufacture deployable metal 3D printers at both port and sea.

Utilizing SPEE3D's metal cold spray 3D printing, the process is purportedly 100 to 1000 times faster than traditional metal 3D printing, enabling the most affordable metal additive manufacturing process to produce industrial quality parts in minutes – from anywhere.

Because the process harnesses the power of kinetic energy rather than relying on high-power lasers and expensive gasses, it allows metal 3D printing at normal production costs.

For the MAINTENX program, SPEE3D will utilize their WarpSPEE3D, the world's first large-format metal 3D printer, which can print large parts or even multiple parts at once.

Evolution of the Industrial Revolution

The assembly line forever changed the way the production of goods was developed, launching mankind into the industrial era. Emerging metal 3D printing technologies may mark a 21st-century evolution of the Industrial Revolution.

Applied Science & Technology Research Organization, or ASTRO America, gets a little sci-fi with the world's largest metal 3D printer for ground vehicle production.

While not quite at the level of those cool scenes in futuristic movies, with incredible production by multidirectional assemblies with too many mechanical arms to count, the tech being developed by ASTRO has begun to take shape with a manufacturing process that draws on the strengths of 3D printing.

One such giant 3D printer being developed for the U.S. Army's Jointless Hull Project will be able to print monolithic vehicle hulls up to 30 feet long, 20 feet wide and 12 feet high. The goal of the project is to print these hulls faster, cheaper, lighter and more durable than could be done with traditional manufacturing.

As for Meltio, it too brings to life a sci-fi aspect by attaching its metal 3D printer to a robotic arm with a nozzle for extruding wire to then be heated with a laser into any shape, bringing three-dimensional to 3D printers, removing the 2D plane most printing is done on and allowing the robotic arm to print from any direction and angle.

The arm gives it full five-axis positioning capability and precision, and Meltio provides a control computer with a flip-up touchscreen for setup and monitoring work. Where all-in-one systems are confined within boxes that restrict the size of the parts one can work on, the Meltio head can work on anything the robot arm can reach.

While ASTRO's printer is a long way from private commercialization, it is a typical trend that, at some point, innovations for military use make their way to the public, whereas Meltio's attachment is available for purchase at roughly US$100,000, a relatively low price to pay for the potential to 3D print in 3D space.

X-rays and 3D printers

As a global leader in additive manufacturing technologies for mass production, Desktop Metal joined forces with Lumafield to use the latter's industrial X-ray computed tomography (CT) platform to scan and 3D print parts and tools quickly and accurately without the need to design painstaking CAD models – the world's first 3D photocopier, so to speak.

Lumafield, a startup founded in 2019 by a team of engineers with experience in designing, manufacturing, and shipping products with global impacts, noticed immediately a major gap in the product development process.

While manufacturing and fabrication technologies have become more complex and sophisticated, the debugging tools that engineers used to solve their design problems have been stuck in the 19th century.

While 3D scanning has previously been proposed as a solution, it has ultimately been limited to capturing just the exterior of the part's features and not its internal makeup, which, when it comes to metal 3D printing, is the most important aspect.

Lumafield's CT platform digitizes parts with a series of X-ray images that capture both external and internal features in detail. Then sending those images through cloud-based software, the company creates a 3D model that can be exported as a mesh representation for 3D printing.

Desktop Metal then can use its own software and 3D printers to turn those models back into high-quality metal or polymer parts, making it possible to seamlessly replace legacy manufacturing processes with in-house 3D printing.

With the addition of a quality control system to be added to an obvious drawback of metal 3D printing – the possibility of structural flaws in the printing process – it won't be long yet until a complete ecosystem for metal 3D printing is brought to full industrialization and a new era of assembly lines creates the next-generation Industrial Age.