Powder power

As laser powder bed additive-layer manufacturing of metal parts continues to make the leap from rapid prototyping to series production, metal powder manufacturers are responding with new materials that rival the performance of the highest-grade foundry products. Scalmalloy, a new aluminum-magnesium-scandium alloy from Airbus APWorks GmbH, is one such offering, according to the company.

Scalmalloy is an aluminum-magnesium-scandium powder from Airbus APWorks. Image courtesy Toolcraft.

Toolcraft produced this automotive pump housing via metal laser melting. Image courtesy Toolcraft.

The corrosion-resistant material reportedly has the specific strength of titanium at a simultaneously high ductility and is more than twice as strong as the aluminum-silicon powder currently in use. Scalmalloy’s ultimate tensile strength is 490 MPa, yield strength is 450 MPa and elongation at break is 8 percent.

“Airbus realized that the mechanical properties of AlSi10, the standard additive manufacturing aluminum alloy, are not sufficient to be used in aerospace applications,” said Angela Grünewald, who’s in charge of business development for Airbus APWorks, which also prints parts. “The need for a high-strength AM aluminum alloy was identified. During the process, a lot of testing of slight chemical modifications, as well as testing of different powder production processes, was done.”

In addition to aerospace parts, such as interior ones, Grünewald noted Scalmalloy is suitable when parts require a combination of high-strength and lightweight properties, including ones for the automotive and robotics industries.

MBFZ toolcraft GmbH is another manufacturer that uses Scalmalloy to 3D print those types of parts. According to Managing Director Christoph Hauck, toolcraft uses an innovative process in which the design data for manufacturing a part is divided into cross sections, which are then formed on top of one another during the laser-melting process.

“Due to a special construction process in which the laser jumps back and forth between predetermined melting points, the precision part is produced with a low amount of tension,” he said. “Heat treatment follows the completion of the manufacturing process and makes the final workpiece completely free of tension and ensures it possesses the desired mechanical properties.”

Grünewald noted the powder is suitable for printing on AM machines from different builders.

Typically, a near-net shape printed workpiece must be turned or milled, as well as polished, to finish it. “The machinability of Scalmalloy is similar to classical high-strength aluminum alloys,” Hauck said.

For more information about Airbus APWorks GmbH, Ottobrunn, Germany, call +49 89-607-28237 or visit www.apworks.de. For more information about MBFZ toolcraft GmbH, Georgensgmünd, Germany, call +49 9172-69-56-0 or visit www.toolcraft.de.