From Copper to Filaments, engineers are developing new materials for 3D printing, advancing its practical use.
In February, Markforged, Watertown, Mass., commercialized a pure copper filament for its printers so they can use this hard-to-machine metal. The filament enables 3D printing of parts with complex geometries, such as sinker EDM electrodes, heat sinks, bus bars, induction coils for metal hardening (eliminating the need to connect coils with brazing) and welding shanks, according to Elissa Silverman, product marketing manager.
“Welding shanks are important in the auto market,” Silverman said. “Welding all these pieces of sheet metal together, in tight areas, means figuring out the most efficient way to weld. Shanks are expensive and have many complex geometries.” Printing complex geometries is also critical for designing and integrating bus bars into a system. “As systems move toward miniaturization and increasing power density, using the space well in electrical systems is insanely important,” said Silverman.
While Markforged is offering a new metal filament, the Lubrizol Corp., Cleveland, has leveraged collaborative development arrangements to commercialize new thermoplastic polyurethane (TPU) in powder and filament form.
Estane 3D TPU M95A is the only thermoplastic polyurethane available for HP’s Jet Fusion 4200 series solution. The materials company has also formulated three Estane 3D TPU grades for fused filament fabrication 3D printing and made them available in the Ultimaker Marketplace.
The added grades include Estane 3D TPU F94A-055 OR HH PL (durable with higher temperature performance), Estane 3DP TPU 98A-030 CR HC PL (excellent mechanical properties with low warpage and shrinkage, and high clarity), and Estane 3DP TPU F70D-065 TR UV PL (flexible in low temperatures while providing UV stability with high transparency).
Lubrizol’s ESTANE 3D TPU grades can be used to print industrial jigs and fixtures, prototypes, end-use parts, and flexible parts.
Meanwhile, scientists at the Graz University of Technology (Austria) applied for a patent on 3D printing metal powder using a high-power LED instead of a laser or electron beam. The LED is equipped with a lens system that changes the diameter of the LED focus between 0.05 and 20 mm during the process. This enables melting larger volumes faster, reducing the time to produce components for fuel cell or medical technology, for example, by an average factor of 20, according to a press release.
The LED beam is more energy efficient than laser or electron beams, Christoph Pelzl, of the university’s media service, pointed out. He noted the printer is engineered to use less powder and argon gas and has a heat recovery system from the cooling system of the glass build plate.
Franz Haas, head of the Institute of Production Engineering at the university and leader of a team that developed the selective LED-based melting technology (SLEDM), sees opportunities to also print bioresorbable magnesium alloy screws for orthopedic surgery. “Thanks to SLEDM, producing such implants would be possible directly in the operating theatre. An LED light is less dangerous than a powerful laser,” he said.