Formnext 2020: Trumpf presents new solutions for 3D metal printing industry

17 Nov 2020

New nozzle doubles process speed in LMD; depowdering boosts automation in laser metal fusion.

Laser and industrial tool developer Trumpf says it is increasing automation and process speeds in its additive manufacturing technologies – and its green laser is fueling new applications by enabling 3D printing of pure copper and precious metals.

At this year’s formnext Connect virtual trade fair 2020, held last week online, the 3D printing and laser specialist showcased new solutions for three key industry trends: speed, automation and new materials.

“The additive technologies market remains very attractive for Trumpf,” commented Klaus Parey, managing director Trumpf Additive Manufacturing. “Customers are particularly excited by our TruPrint 1000 machine with a green laser beam source, which is designed for industrial use. Short-wavelength green laser light is the best option for welding pure copper and precious metals.”

Novel nozzle

Coatings to protect against wear and corrosion are often used on parts such as brake disks, hydraulic cylinders and gaskets. The metallic coatings are applied using laser metal deposition (LMD), which has proved to be an excellent choice over many years.

LMD produces high-quality coatings that are almost completely crack-free and non-porous. Using the standard LMD method, the processing rate per unit area – typically lies between 10 and 50 square centimeters per minute. The high-speed variant of LMD, also known as EHLA, can currently reach speeds of between 250 and 500 square centimeters per minute in industrial settings.

Trumpf has developed a new nozzle technology that increases the coating speed to well over 600 square centimeters per minute, even reaching speeds as high as 1,000 square centimeters per minute in certain applications.

The secret lies in using more powder, higher laser power and a nozzle designed specifically for industrial use. Applying a coating faster obviously means using more powder. But using more powder only works if it can be melted fast enough. That’s where the second ingredient in the mix comes in: higher laser powers of up to 8kW.

Yet these high laser powers can only be used in tandem with a robust, properly cooled nozzle. And it’s exactly this combination that Trumpf has brought together in its new nozzle technology, which enables significantly higher coating speeds than ever before – especially for rotationally symmetrical parts.

At this year’s formnext, Trumpf also presented a new depowdering station for the powder bed-based additive manufacturing process of laser metal fusion (LMF). This system unpacks and depowders 3D-printed metal parts, combining two process steps in one machine.

The system turns the printed part upside down and, if necessary, starts to vibrate, until almost all the excess powder has been removed. This new depowdering machine also protects the machine operator from hazardous particles by carrying out powder removal in the process chamber while it is still flooded with inert gas.

Copper, gold and platinum processing

At the formnext fair held in 2018, Trumpf demonstrated for the first time how a disk laser in the green wavelength range can be used to print pure copper and precious metals. Conventional 3D printers that use infrared light cannot process materials such as copper and gold, because their highly reflective surfaces prevent melting from occurring.

But because green light has a much shorter wavelength than infrared, it opens the door to 3D printing of pure copper and precious metals. Since its launch, Trumpf’s TruPrint 1000 Green Edition has carved out a solid position in the market, the company said.

Customers include Toolcraft, which is using the machine to produce parts for various industries, and the company C. Hafner, which uses it to make watch cases out of red gold and platinum. Trumpf’s “green printers” are also a popular tool at Fraunhofer IWS, where several institutes are putting the TruPrint 1000 Green Edition to use in various fields of research.