Tech Briefs Magazine - September 2021 - 44

Manufacturing & Prototyping
" Fingerprints " for 3D Printers
Printers can be identified by their unique hot end, aiding intellectual property and security.
University at Buffalo, New York
o reduce illicit use of 3D printers,
researchers are developing a way to
track the origin of 3D-printed items. The
technology would protect intellectual
property from someone else printing the
same design using their own printer.
3D printers build three-dimensional
objects by adding successive layers of printing
materials according to the digital
design for a 3D model. Each 3D printer
has an extruder that pushes the building
material along. The extruder's hot end
then melts the material and places it on
the print bed to build the model. Each
extruder's hot end has its own unique
heating properties that impact the precise
way that the 3D model is constructed.
T
Those thermodynamic properties can
be used to identify the specific extruder
and the model of 3D printer as uniquely
as a human fingerprint, or ThermoTag.
The process is similar to using a laptop to
write a letter. Because software exists that
can track keystrokes, an observer can see
every step that went into the letter including
the writer's unique writing style.
Similarly, because of the unique properties
of each 3D printer's extruder, a
researcher can examine the specific manner
in which a 3D-printed object was
made and compare that to a database of
various extruders until a match is made.
From there, once the model printer is
identified, the purchaser of said model
can be tracked down if they had, for
example, used the printer to build an illegal
assault rifle.
By examining and comparing the
ThermoTag features of 45 different ex -
truders of the same model, the researchers
were able to correctly identify the source
printer with an accuracy rate of 92%.
When printing out a new product, watermarking
can be used to invisibly embed
such information as the printer's manufacturer,
label, and serial number in the product.
That would make the watermark of a
particular product unique.
For more information, contact Media
Relations at ub-news@buffalo.edu; 716-6456969.
Abnormal
Grain Growth Suppression in Aluminum Alloys
Applications include manufacturing structural components for aerospace vehicles, cars,
trucks, trains, ships, and submarines.
Langley Research Center, Hampton, Virginia
post-friction stir welding heat treatment
procedure was developed that
reduces abnormal grain growth and
restores optimum material properties in
heat-treatable aluminum alloys. The
innovation is a thermal processing meth -
Welding direction
parallel to plate
rolling direction
Original thickness
of material during
friction-stir-welding
A
odology for retaining the fine-grained
structure in aluminum alloys subjected
to solid-state welding and subsequent
forming processes.
Heat treatment of the deformed welds is
desirable in order to restore the properties
Weld Crown
S
L
Parent
Metal
Axes
T
WELD
NUGGET
Weld Root
As Spin-Formed
44
Cov
As Solution-Treated
An intermediate annealing step reduces abnormal grain growth. (Image: NASA/Stephen J. Hales)
www.techbriefs.com
ToC
Material thickness
following contour
machining and
spin-forming
of the alloy negatively affected in the weld
region. In these alloys, abnormal grain
growth frequently occurs in friction stir
welds during solution heat treatment and is
known to degrade key materials properties
such as strength, ductility, and toughness.
The innovation of inserting an intermediate
annealing step reduces abnormal
grain growth during post-welding heat
treatment, thereby allowing optimum
mechanical properties. This is im portant
where Al-Li alloys (and other heat-treatable
alloys) are friction stir welded followed by
deformation process ing. It is especially
applicable for high-performance, highreliability
structural com ponents required
for aerospace vehicles.
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/LARTOPS-225.
Tech
Briefs, September 2021
Retreating Side
Advancing Side

https://technology.nasa.gov/patent/LAR-TOPS-225 http://www.techbriefs.com http://www.abpi.net/ntbpdfclicks/l.php?202109TBNAV

Tech Briefs Magazine - September 2021

Table of Contents for the Digital Edition of Tech Briefs Magazine - September 2021