Tech Briefs Magazine - July 2021 - 31

Manufacturing & Prototyping
Overhang Support Designs for Powder-Based Electron
Beam Additive Manufacturing (EBAM)
The supports enable the production of higher-quality, less-expensive parts via additive
manufacturing.
Marshall Space Flight Center, Alabama
N
ASA Marshall developed a contactfree
support structure used to fabricate
overhang-type geometries via EBAM.
The support structure is used for 3D
metal-printed components for the aerospace,
automotive, biomedical, and
other industries. Current techniques use
support structures to address deformation
challenges inherent in 3D metal
printing; however, these structures (overhangs)
are bonded to the component
and need to be removed in post-processing
using a mechanical tool. This new
technology improves the overhang support
structure design for components by
eliminating associated geometric defects
and post-processing requirements.
EBAM technology is capable of making
full-density, functional metallic components
for numerous engineering applications
in industries where high-value, lowvolume,
custom-designed productions
are required. A key challenge in EBAM is
overcoming deformation of overhangs
that are the result of severe thermal gradients
generated by the poor thermal
conductivity of metallic powders used in
the fabrication process. Conventional
support structures address the deformation
challenge; however, they are bonded
to the component and need to be re -
moved in post-processing using a me -
chanical tool. This process is laborious,
time-consuming, and degrades the surface
quality of the product.
The invented support design fabricates
a support underneath an overhang
by building the support up from the
build plate and placing a support surface
underneath an overhang with a certain
gap (no contact with overhang).
The technology deposits one or more
layers of unmelted metallic powder in an
elongate gap between an upper horizontal
surface of the support structure and a
lower surface of the overhang geometry.
The support structure acts as a heat sink
to enhance heat transfer and reduce the
temperature and thermal gradients. Be -
cause the support structure is not connected
to the part, the support structure
can be removed freely without any postprocessing
step.
Future work will compare experimental
data with simulation results in order to
validate process models as well as to study
process parameter effects on the thermal
characteristics of the EBAM process.
NASA is actively seeking licensees to commercialize
this technology. Please contact
NASA's Licensing Concierge at AgencyPatent-Licensing@mail.nasa.gov
or call us
at 202-358-7432 to initiate licensing discussions.
Follow this link for more information:
https://technology.nasa.gov/patent/MFSTOPS-41.
Eco-Friendly
Technique Upcycles Metal Waste into
Multipurpose Aerogels
Potential applications include lightweight building materials and growing cells for
biomedical purposes.
National University of Singapore
C
onventional approaches for recycling
metal waste are energy-intensive
and some also generate environmentally
harmful byproducts such as
ammonia and methane during aluminum
recycling. To address this challenge,
researchers demonstrated an ecofriendly
technique to convert aluminum
and magnesium waste into high-value,
multifunctional aerogels. This upcycling
method could be applied to all types of
metal waste such as metal chips and electronic
waste.
The approach does not produce any
hazardous waste, consumes less energy,
and is more environmentally friendly
Tech Briefs, July 2021
Cov
than conventional recycling methods for
metal waste. The metal-based aerogels
created using the fabrication technique
have high thermal and mechanical stability,
making them candidates for heat
and sound insulation in harsh environments
with high-temperature or high
mechanical impact.
The team developed a simple fabrication
process to create metal-based aerogels.
Metal waste is first ground into
powder and mixed with chemical crosslinkers.
The mixture is heated in the
oven, frozen, and then freeze-dried to
create the aerogel. The process may vary
slightly, depending on the metal waste
www.techbriefs.com
ToC
involved. On average, it takes about one
to three days to transform powdered
metal waste into aerogels, compared to
three to seven days using conventional
methods of producing aerogels.
Aerogels are highly absorbent, ex -
tremely light, and have excellent thermal
and sound insulation capabilities.
The properties of aerogels can be
altered by coating them with chemicals;
for example, they can become waterrepellent
or fire-resistant.
Aluminum aerogel is 30 times lighter
and insulates heat 21 times better than
conventional concrete. When optical
fibers are added during the mixing
31
https://technology.nasa.gov/patent/MFS-TOPS-41 http://www.techbriefs.com http://www.abpi.net/ntbpdfclicks/l.php?202107TBNAV
Tech Briefs Magazine - July 2021

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