electron beam freeform fabrication
Eugen Leitl
http://news.yahoo.com/s/space/20091105/sc_space/devicelikestartrekreplicatormightflyonspacestation
Device Like 'Star Trek' Replicator Might Fly on Space Station
Jeremy Hsu
space.com – Thu Nov 5, 8:39 am ET
Space explorers have yet to get their hands on the replicator of "Star Trek"
to create anything they might require. But NASA has developed a technology
that could enable lunar colonists to carry out on-site manufacturing on the
moon, or allow future astronauts to create critical spare parts during the
long trip to Mars.
The method, called electron beam freeform fabrication (EBF3), uses an
electron beam to melt metals and build objects layer by layer. Such an
approach already promises to cut manufacturing costs for the aerospace
industry, and could pioneer development of new materials. It has also
thrilled astronauts on the International Space Station by dangling the
possibility of designing new tools or objects, researchers said.
"They get up there, and all they have is time and imagination," said Karen
Taminger, the materials research engineer heading the project at NASA's
Langley Research Center in Virginia.
Taminger's project has undergone microgravity tests aboard NASA's "vomit
comet" aircraft. Now she hopes to get EBF3 scheduled for launch to the
International Space Station, so that space trials can commence.
Shaping metals at will
EBF3 requires a few crucial components: power for its electron beam, a vacuum
environment, and a source of metals. While Star Trek's replicator could work
without a supply of subatomic particles, reality is a different story.
"It'd be nice if we could build something from nothing, but it doesn't work
that way," Taminger told SPACE.com.
For EBF3, metal wires continually feed into the tip of an electron beam. The
beam melts the wires and applies them carefully on top of a rotating plate to
build an object up slowly, layer by layer.
A few similar technologies exist, but EBF3 has several advantages. First, its
electron beam requires far less power than comparable devices and produces
less radiation compared to more powerful beams. Its dual wire feeders also
allow scientists to create mixes of new materials that vary in strength or
other properties within the same solid piece.
"We can change the composition on the fly," Taminger explained. "You can add
alloys of different chemistries and then adjust the speed that you feed the
wires, and that would change the chemistry of the parts we build."
The flexibility of the manufacturing could also embed fiber optic cables
inside a solid piece of metal, either for use in communication or for
monitoring stresses within the manufactured part.
Major aerospace manufacturers have already begun running thousands of
strength tests with the EBF3 device to see whether it can produce certified
parts for engines and airframes, researchers said. They foresee cost savings
of up to $1,000 per pound of manufactured parts, compared to the usual
forging and machining methods that require a 6,000-pound block of titanium to
produce a 300-pound part.
Testing in microgravity
Early "vomit comet" tests on NASA's C-9 aircraft showed that EBF3 could work
well in a zero-g environment. Taminger and her team managed to build a number
of parts that looked exactly the same as parts built on Earth, down to the
microstructure scale.
Some researchers had predicted that the method would fail to produce anything
but "ball bearings," or liquid metallic spheres in zero-g. But the wire
feeders successfully deposited the metal layers onto the rotating plate as
usual, except for the occasional misaligned wire that would create a growing
sphere on its end.
"We learned a lot more when things went wrong," Taminger said. "When things
go wrong in zero-gravity, you just don't have as much experience to guess
what would happen."
The effects of zero-g often comically exaggerated any mistakes, and allowed
the team to improve the overall process for Earth manufacturing as well. They
even ran a few experimental tests going from zero-g to two gees as the C-9
aircraft would pull out of its steep dive.
The big next step for EBF3 involves going to the space station. Taminger has
already gotten the device down to a "suitcase style experiment" that fits
within a volume of less than eight cubic feet, but still needs funding and a
possible slot aboard one of the remaining space shuttle missions. The device
could also go up on a contracted NASA flight with the Russian Soyuz rockets,
or even a private launch.
Going to the space station means that EBF3 can take advantage of the vacuum
environment in space, and sit on an outside rack -- perhaps the "back porch"
of Japan's Kibo space lab.
Spare parts for Mars
Beyond low-Earth orbit, such new manufacturing technology could enable space
colonists to use local metal resources mined from the moon, Mars or in the
asteroid belt.
Past simulations have also shown that spaceships would require many spare
parts for the long journey to Mars, because different parts failed during
each simulation. But the total weight of parts that failed during each run
was roughly the same, which suggests a Mars mission could simply take along
metal feedstock and an EBF3 device.
"If we've got a broken part, we can even repurpose that into feedstock, or
can we mine new material," Taminger said. "The short term solution is that
you bring along the material you need, but you don't need to bring the parts
that you need."
The EBF3 device probably won't churn out spare parts immediately, if it
reaches the space station. But astronauts who have seen the device in action
have expressed excitement over the idea of making their own tools, 21st
century pioneer style.
"They can build a shovel, or a clamp or a widget, or whatever they might come
up with," Taminger said. "They're not just stuck with the toolbox they
brought along."
Paul D. Fernhout
> http://news.yahoo.com/s/space/20091105/sc_space/devicelikestartrekreplicatormightflyonspacestation
>
> Device Like 'Star Trek' Replicator Might Fly on Space Station
>
> Jeremy Hsu
>
> space.com – Thu Nov 5, 8:39 am ET
>
> Space explorers have yet to get their hands on the replicator of "Star Trek"
> to create anything they might require. But NASA has developed a technology
> that could enable lunar colonists to carry out on-site manufacturing on the
> moon, or allow future astronauts to create critical spare parts during the
> long trip to Mars.
>
> The method, called electron beam freeform fabrication (EBF3), uses an
> electron beam to melt metals and build objects layer by layer. Such an
> approach already promises to cut manufacturing costs for the aerospace
> industry, and could pioneer development of new materials. It has also
> thrilled astronauts on the International Space Station by dangling the
> possibility of designing new tools or objects, researchers said.
>
> "They get up there, and all they have is time and imagination," said Karen
> Taminger, the materials research engineer heading the project at NASA's
> Langley Research Center in Virginia.
>
> Taminger's project has undergone microgravity tests aboard NASA's "vomit
> comet" aircraft. Now she hopes to get EBF3 scheduled for launch to the
> International Space Station, so that space trials can commence.
Why isn't there a better way we can all be aware of ongoing research? Why do
these things seem to pop out of nowhere as finished ideas? Is it me? Or is
there something about how research is done globally that is not integrated
somehow? Or could be better integrated? So much more cooperation that could
go on, I would think.
> Shaping metals at will
>
> EBF3 requires a few crucial components: power for its electron beam, a vacuum
> environment, and a source of metals. While Star Trek's replicator could work
> without a supply of subatomic particles, reality is a different story.
>
> "It'd be nice if we could build something from nothing, but it doesn't work
> that way," Taminger told SPACE.com.
>
> For EBF3, metal wires continually feed into the tip of an electron beam. The
> beam melts the wires and applies them carefully on top of a rotating plate to
> build an object up slowly, layer by layer.
>
> A few similar technologies exist, but EBF3 has several advantages. First, its
> electron beam requires far less power than comparable devices and produces
> less radiation compared to more powerful beams. Its dual wire feeders also
> allow scientists to create mixes of new materials that vary in strength or
> other properties within the same solid piece.
>
> "We can change the composition on the fly," Taminger explained. "You can add
> alloys of different chemistries and then adjust the speed that you feed the
> wires, and that would change the chemistry of the parts we build."
This reminds me that my father worked on helping improve flame spray
equipment, used to build up worn shafts, or what he worked on, coat metal on
ceramics (for an experiment for CorningWare to make it heat faster on
stoves). There is a picture of what looks the the kind of flame spray guns
(at METCO, later bought by Perkin Elmer) he worked on here:
http://en.wikipedia.org/wiki/Thermal_spraying
More on that now that I think to look it up:
http://www.fundinguniverse.com/company-histories/The-PerkinElmer-Corporation-Company-History.html
"""
During the 1960s, the company made some acquisitions supplementing internal
expansion of its instrument line. Then, in the 1970s, in line with a trend
in American corporate culture, Perkin-Elmer undertook a number of ambitious
diversification moves. The foundation was laid for what Perkin-Elmer calls
its material sciences business with the acquisition in September 1971 of
METCO Inc. of Westbury, New York, the leading supplier of plasma and flame
spray material and equipment. (After acquiring the corporation, Perkin-Elmer
opted to lowercase the name to "Metco.") The Metco thermal spraying process
applied a metal or ceramic coating to improve a part's wear, corrosion rate,
or heat resistance. The improved surface provided by such spraying can
permit the use of less expensive materials in all sorts of machinery and
engine components.
"""
I never have thought much before about a direct connection between my
father's work there and aspects of 3D printing. Thanks.
> Beyond low-Earth orbit, such new manufacturing technology could enable space
> colonists to use local metal resources mined from the moon, Mars or in the
> asteroid belt.
> ...
> "They can build a shovel, or a clamp or a widget, or whatever they might come
> up with," Taminger said. "They're not just stuck with the toolbox they
> brought along."
So true, and even true on Earth. :-)
--Paul Fernhout
http://www.oscomak.net/
http://www.pdfernhout.net/
http://www.beyondajoblessrecovery.org/