Tech Briefs Magazine - January 2023 - 37

APPLICATION
BRIEFS
Leveraging Metal 3D Printing for Manufacturing in Space
Fabrisonic
Columbus, OH
www.fabrisonic.com
D
eveloping a system to build lightweight, efficient structures
in orbit will revolutionize space travel. It is nontrivial and
the efficiency of launch, deployment, and employment in
space is a key objective and challenge.
Structures built for use in space must meet vastly different
requirements than terrestrial structures. Although temperature
variations occur on Earth, they are negligible compared to
the variations a space vehicle may see in orbit. The force of
gravity is negligible in space while significant on Earth. Getting
any structure engineered and manufactured on Earth into
space adds extraordinary requirements to withstand the loading
and g-forces placed on the structure to withstand a space
launch. The answer to that challenge is to transport only the
raw materials and tools needed to manufacture all the structural
elements in space.
To that end, 3D printing holds much promise. NASA already has
several plastic printers in orbit and has been ramping up research
for metal-based systems. One promising metal-based additive technology
is Ultrasonic Additive Manufacturing (UAM). Instead of
fusing metal powders, UAM welds foil at (near) room temperature.
When considering manufacturing in space, some critical
considerations must be addressed.
1. Welding in space is subject to small gravitational forces. A
small gravitational force greatly affects the mechanisms necessary
for successful fusion-based welding processes.
2. Welding in space has almost no atmosphere. The lack of
interaction with gasses can cause process instability in traditional
fusion processes. Arc-based processes require gas
ionization to function, while laser/EB processes rely on atmospheric
pressure for developing beam keyholing.
3. Welding in space requires accounting for wild temperature
variations. While terrestrial welders can control thermal fluctuations
to within tens of degrees, structures in space can experience
fluctuations of several hundred degrees.
4. Welding processes in space must use significantly less power
due to limited power sources. Fusion-based welding systems
can require hundreds of kilowatts of power to heat and melt
metal. Terrestrial power sources can easily accommodate
such power requirements. However, systems in space run on
extremely tight power budgets.
The fundamental characteristic separating UAM from other
metallic additive manufacturing technologies is that UAM is a
solid-state welding process. Metals remain in their solid state,
and melting does not occur at any time during the process. All
the attendant impacts of high-temperature welding and the effects
on the properties of the metal do not occur.
The results and advantages of employing UAM in space
manufacturing include low power consumption as most
welding heads use much less power; as a solid-state process,
the feedstock retains 97 percent of its original properties;
operates without (and with) an atmosphere, does not require
any welding filler material; does not cause heat-affected
zones; does not require post-process stress relieving.
The nature of the solid-state ultrasonic bonding process used
in UAM will enable the building of
space flight components without the
complexity of molten metals or difficult-to-manipulate
powders.
Several NASA programs have contributed
toward the use of UAM for welding
in space. Through Phase I and II SBIR
programs, Fabrisonic built a welding system
that met the in-orbit manufacturing
requirements. The standard (terrestrial)
Fabrisonic industrial metal 3D
printers have been in production since
2011. They can weigh up to 35 tons and
use over 10kW of electrical power.
NASA presented these challenges
to Fabrisonic:
* Can the UAM welding assembly be
scaled down to save power, weight,
and size?
* Can a concept be designed to fit the
bounds of NASA requirements?
A multi-material piston printed using the SonicLayer 1200. This includes both aerospace-grade aluminum
for strength and copper for thermal conductivity. (Image: Fabrisonic)
Tech Briefs, January 2023
www.techbriefs.com
* Can the UAM system be remotely
controlled to build practical structures
in low-Earth orbit?
37

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Tech Briefs Magazine - January 2023

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