TRUMPF introduces copper and gold 3D printing enabled by green laser tech

German machine tool manufacturer TRUMPF is seeking to expand the versatility of metal materials for its additive manufacturing technology. As announced at Formnext last week, the company’s TruPrint 5000 is capable of printing high-carbon steel or titanium alloys, while a new green laser with pulse product enables the printing of pure copper and other precious metals.

Put on the green light

TRUMPF introduced a new green laser with pulse function in Frankfurt last week, demonstrating its capacity to 3D print pure copper and other precious metals. This groundbreaking ability, says the company, could have important implications in mechanical and plant engineering applications, as copper is well suited for producing conductive inductors and heat exchangers.

The green laser technology also has applications in the jewelry industry, as it could be used to print detailed pieces from gold or other precious metals. “The 3D printer doesn’t waste expensive gold and silver,” said Thomas Fehn, TRUMPF General Manager Additive Manufacturing for sales. In other words, jewelry makers could actually save money by reducing material waste.

To demonstrate how it could print copper, TRUMPF connected the TruDisk 1020 disk laser to the TruPrint 1000 machine. The green laser, as opposed to a more traditional infrared laser, has the right wavelength to melt and weld precious metals. As Fehn explains, “Conventional systems use an infrared laser as the beam source, but its wavelength is too long and it can’t weld highly reflective materials such as copper and gold. This can be done with laser light in the green wavelength spectrum.”

Notably, EOS also presented new copper materials at Formnext last week in addition to its new LaserProFusion system for polymer AM.

Preheat the printer to 500°C

At Formnext, TRUMPF also demonstrated how its TruPrint 5000 3D printer could—when preheated to 500°C—print high-carbon steel and titanium alloys without risk of cracking or warping. This capability could open the doors for manufacturers to create forming tools, punches and dies, something that was previously a challenge with AM.

High-carbon steel, such as carbon tool steel 1.2343, is an extremely tough and wear-resistant material that is commonly used by tool and mold makers because of these properties and its ability to dissipate heat well. Up until now, however, it has been a challenging material to work with in additive manufacturing because of the risk of cracking.

As Tobias Baur, TRUMPF General Manager Additve Manufacturing for technology, explained: “The laser beam melts the component surface, which subsequently cools back down to room temperature. The components weren’t able to withstand this temperature drop, and cracks formed.”

This hurdle has now been overcome by preheating the substrate of the TruPrint 5000 machine to 500°C, which results in a lower temperature drop during the print process. “The material quality and surface of carbon steels are significantly better than without preheating, preventing fractures in the components,” Baur added.

TRUMPF also highlights that the preheating feature of the TruPrint 5000 can also have advantages for the production of implants and prosthetics, as it can print titanium parts with reduced stresses and improved quality. Notably, preheating the printer can also eliminate the need for support structures in a part.

“When the ambient temperature drops too sharply, the parts warp and we have to rework them,” Baur elaborated. “In addition, we often require support structures that are difficult to set up and take down.”