Desktop Metal close to 3D printing breakthrough
Desktop Metal is close to unveiling a commercial 3D metal printer, which if successful could revolutionise manufacturing. Using metal in 3D printing has so far been extremely difficult, mainly because of most metals' high melting point. Desktop Metal uses metal powders combined with flowable polymer binders instead of the extruded plastic commonly used in 3D printing. The technique allows metal parts to be printed at temperatures much lower than their melting points. The firm has raised nearly $100m from VCs and the venture arms of GE, BMW and Alphabet.
 

 

As Fulop moves about the large, open workspace, his excitement and enthusiasm seem tempered by anxiety. The final commercial printers are not yet ready. Employees are busy tinkering with the machines, and fabricated test objects are scattered about. Progress is being made, but it’s also obvious that the clock is ticking. In a corner near the front door and entrance area, the floor is empty and taped off; soon the space needs to be filled with a mockup of the company’s planned booth for an upcoming trade show.

If it succeeds, Desktop Metal will help solve a daunting challenge that has eluded developers of 3-D printing for more than three decades, severely limiting the technology’s impact. Indeed, despite considerable fanfare and evangelical enthusiasts, 3-D printing has, in many ways, been a disappointment.

Hobbyists and self-proclaimed makers can use relatively inexpensive 3-D printers to make wonderfully complex and ingenious shapes out of plastics. And some designers and engineers have found those machines useful in mocking up potential products, but printing polymer parts has found little use on the production floor in anything but a few specialized products, such as customized hearing aids and dental implants.

Though it is possible to

3-D-print metals, doing so is difficult and pricey.

Though it is possible to 3-D-print metals, doing so is difficult and pricey. Advanced manufacturing companies such as GE are using very expensive machines with specialized high-power lasers to make a few high-value parts (see “Additive Manufacturing” in our 10 Breakthrough Technologies list of 2013). But printing metals is limited to companies with millions to spend on the equipment, facilities to power the lasers, and highly trained technicians to run it all. And there is still no readily available option for those who want to print various iterations of a metal part during the process of product design and development.

A hydraulic manifold is processed inside a microwave furnace, which uses temperatures up to 1,400 °C to sinter the steel part. Such a part is too complex to make with conventional methods.

The shortcomings of 3-D printing mean the vision that has long excited its advocates remains elusive. They would like to create a digital design, print out prototypes that they could test and refine, and then use the digital file of the optimized version to create a commercial product or part out of the same material whenever they hit “make” on a 3-D printer. Having an affordable and fast way to print metal parts would be an important step in making this vision a reality.

It would give designers more freedom, allowing them to create and test parts and devices with complex shapes that can’t be made easily with any other production method—say, an intricate aluminum lattice or a metal object with internal cavities. It could eventually enable engineers and materials scientists to create parts with new functions and properties by depositing various combinations of materials—for example, printing out a magnetic metal next to a nonmagnetic one. Beyond that, it would redefine the economics of mass production, because the cost of printing something would be the same regardless of how many items were produced. That would change how manufacturers think about the size of factories, the need for backup inventory (why keep many parts in stock if you can simply and quickly print one out?), and the process of tailoring manufacturing to specialized products.

This is why there has been a race to turn 3-D printing into a new way to produce parts. Longtime suppliers of 3-D printers, including Stratasys and 3D Systems, are introducing increasingly advanced machines that are fast enough for manufacturers to use. Last year, HP introduced a line of 3-D printers that the company says will allow manufacturers to prototype and make products with nylon, a widely used thermoplastic. And last fall, GE spent over a billion dollars on a pair of European companies specializing in 3-D-printing of metal parts.

This steel propeller has just been printed. Between the propeller’s blades and the metal support is a thin line of ceramic, which will turn to sand during the sintering process, allowing the finished part to be easily separated from the support.

The propeller after processing provides an example of a high-performance part that can be made with 3-D printing. Engineers can use the method to prototype and optimize different designs.

But the real competition for Desktop Metal is probably not from the growing number of companies in 3-D printing. For one thing, the 3-D printers from HP, Stratasys (an investor in Desktop Metal), and 3D Systems mainly use various types of plastics, not the range of metals Fulop’s company wants to use in its printers. And GE’s high-end machines overlap little with Desktop Metal’s market ambitions. Instead, the real competitors for Desktop Metal are more likely to be established metal-processing technologies. Those include automated machining techniques—such as the method used to make the ultra-thin aluminum back casing of iPhones—and a rapidly growing practice called metal injection molding, a common way to mass-produce metal products.