High-Strength Aluminum Powder Developed for Additive Manufacturing in Aerospace, Automotive

August 1, 2015

Ryan Gehm

Metal laser melting has made a successful leap from rapid prototyping to an approved manufacturing technology, and the method is increasingly becoming an option for companies in high-tech industries, according to Toolcraft. And now the German manufacturer has teamed with Airbus APWorks to offer another option for additive manufacturing—the Airbus subsidiary’s Scalmalloy high-performance aluminum powder.

“The cooperation between Toolcraft and Airbus APWorks has existed since the beginning of this year and as of now we process Scalmalloy,” Christoph Hauck, Managing Director at Toolcraft, shared with Aerospace Engineering. Regarding challenges using the material, Hauck noted that Scalmalloy is a completely new alloy, so “the components need a fully new development of parameters.”

Toolcraft also uses nickel and titanium alloys, stainless and tool steels, as well as aluminum-silicon alloys in its metal laser melting process. Any material that is weldable can be processed.

Scalmalloy is described as a corrosion-resistant material with the specific strength of titanium at a simultaneously high ductility. It is more than twice as strong as the aluminum-silicon powder currently in use, according to Toolcraft. These properties make the new alloy ideally suited for high-performance applications in the aerospace, aviation, and automotive industries, as well as for special machinery manufacturing: “For example, highly durable parts with extraordinary high-strength properties,” Hauck added.

Toolcraft continuously seeks to improve its procedures and to expand its material base, Hauck noted, so materials- procurement partners are essential. “The Airbus Group has produced a type of powder that not only exhibits the positive properties of aluminum, but also very high strength with good elongation at break. Scalmalloy is therefore unique in the market,” he said.

Scalmalloy is more expensive than standard aluminum alloys, according to Hauck: “There is no serial production of the material yet. The costs can be compared with titanium powder.”

In the field of metal laser melting, Toolcraft provides a range of processes from engineering to additive manufacturing and heat treatment to finishing by turning or milling, as well as final tactical or optical measuring. It also uses a system for nondestructive surface testing and meets the requirements of the EN 9100 certificate for aerospace applications.

The cooperation with Airbus APWorks—the technical consulting firm and production operation for additive metal components at the Airbus Group—strengthens the process chain through enhanced topology optimization of the design data. Components can be evaluated in advance, taking advantage of the possibilities provided by additive manufacturing for potential redesigns, parts consolidation, and weight reduction.

“The additive manufacturing process builds up a workpiece layer by layer, as the laser melts the material concerned in powdered form,” Hauck explained. “The material is checked for different properties by different analytic tools. The design data for the manufacture of the piece is divided into cross sections and then formed on top of one another during the melting process. The piece is thus literally built up in a ‘3D’ way.”

Four laser melting machines from Concept Laser are in use. The machines offer a workspace of 250 × 250 × 280 mm in the x, y, and z directions. They melt down layers measuring 20-80 μm in thickness at a speed of 2-20 cm³/h depending on the material. The laser has an output of 400 W.

The new Scalmalloy material is now ready for production applications, Hauck said.