Market research firm IDTechEx predicts that the global market for 3D printing metals will hit $12 billion by 2028. This growth in metal additive manufacturing (AM) will not only be due to greater adoption of the technology, as prices drop and new technology emerges, but also to the expansion of the materials portfolio itself.
Currently, metal materials for AM are pretty limited, particularly when it comes to powder bed fusion, the most widespread metal 3D printing technology on the market. This means that we’re going to see a number of initiatives established to make more metals available for powder bed systems.
Among the companies taking advantage of this new frontier is Elementum 3D, which is developing new metal powders for powder bed fusion that have some unique properties. ENGINEERING.com spoke with the company’s president, Jacob Nuechterlein.
Starting with Aluminum
After studying powder metallurgy at the Colorado School of Mines, Nuechterlein started working as a materials science consultant when he began to see the limited materials available in metal AM. It was then that he founded Elementum 3D.
“There’s thousands of materials to choose from, so why are there only six or seven metals for AM?” Nuechterlein asked. “Our goal was to expand the materials library for AM and found that the largest market was laser powder bed. That’s what we’ve been going after, developing new materials for laser powder bed from a couple of different techniques.”
The startup’s first material to be released is its aluminum metal-matrix composites (MMC), a metal matrix with a ceramic particulate dispersed within it. The only way it can be printed is through Elementum’s proprietary reactive AM (RAM) technique. “We use a technology called RAM and essentially we’re using solid-state chemical reactions to form different cross phases in the equipment,” Nuechterlein explained.
The use of ceramics in the composite means a stronger, harder, stiffer metal with great wear resistance. The aluminum MMC is similar to 7075 aluminum. It’s harder and stronger than the AlSi10Mg aluminum alloy typically used in 3D printing, and it’s even harder and stronger than steel. It also has a higher strength-to-weight ratio, comparable to titanium, but is less heavy, less expensive and faster to print.
“Typically, 2000-series aluminum is not printable using standard laser powder beds, but when you use our RAM process with the MMC, that makes the material printable and consistent,” Nuechterlein said. “One of the big advantages of this is that it increases the operating temperature. A typical aluminum will be a very soft at 100 °C, but this material has a strength better than 6061 [aluminum] at elevated temperatures.”
The combination of temperature resistance and high stiffness makes the material useful for aerospace, automotive and tooling applications. Business Development director for Elementum 3D, Patrick Callard, pointed out that the material could find itself in the engine area of a car, such as the piston heads or push rods, as well as the breaking system or anywhere in which wear resistance could be key.
The material’s wear resistance does introduce some obstacles. For instance, machining is very difficult, according to the company. “It’s so wear resistant that it will wear down carbide tooling, so you have to use diamond or wire [electrical discharge machining],” Nuechterlein said. “Adding ceramic also decreases the ductility.”
Elementum has partnered with EOS, manufacturer of direct metal laser sintering (DMLS) systems, for the aluminum MMC material, which will be sold exclusively by EOS. The material will be available for use on EOS DMLS 3D printers later this year.
Expanding the Material Set
To develop new materials, Elementum prefers to work with partners who have interests in specific materials. The partner may provide base metals for experimentation and/or the specific tests required of that material.
As the material is developed, Elementum prints test cubes and standard tensile coupons to perform a variety of mechanical tests, as well as metallography to characterize the microstructure of the material under a microscope.
Once the material is developed, the startup licenses its RAM technique to the company. Powder bed systems capable of using the material don’t have to be modified at all. Instead, Elementum essentially licenses the machine parameters that make the material printable.
Not all materials developed by Elementum require the RAM process. For instance, the startup aims to have pure copper and pure tungsten materials, and their associated machine parameters, on the market by the end of the year.
The company is still quite new, so it may be some time before we hear more about how these materials are being used. NASA, however, is Elementum’s first customer and there will likely be more on the way.
To learn more, visit the Elementum 3D website.