al-li 2000 series alloy out gassing studies at iit n. solomey, physics division philippe nash,...
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![Page 1: Al-Li 2000 series alloy out gassing Studies at IIT N. Solomey, Physics Division Philippe Nash, Material Science Division 21 Feb. 2003](https://reader036.vdocuments.mx/reader036/viewer/2022062518/56649d555503460f94a3216b/html5/thumbnails/1.jpg)
Al-Li 2000 series alloy out gassing Studies at IIT
N. Solomey, Physics Division
Philippe Nash, Material Science Division
21 Feb. 2003
![Page 2: Al-Li 2000 series alloy out gassing Studies at IIT N. Solomey, Physics Division Philippe Nash, Material Science Division 21 Feb. 2003](https://reader036.vdocuments.mx/reader036/viewer/2022062518/56649d555503460f94a3216b/html5/thumbnails/2.jpg)
Current knowledge of Al-Li 2195
• NASA has extensive knowledge and many internal reports for this alloy for:– Welding– Cryogenic
• There is no known knowledge about:– Out gassing with first use of the alloy– Thin wall structures for vacuum to air,
hydrogen or liquid cryogenics.– Radiation damage.
![Page 3: Al-Li 2000 series alloy out gassing Studies at IIT N. Solomey, Physics Division Philippe Nash, Material Science Division 21 Feb. 2003](https://reader036.vdocuments.mx/reader036/viewer/2022062518/56649d555503460f94a3216b/html5/thumbnails/3.jpg)
We are using the Molly Furnace in P. Nash’s Lab at IIT• Large volume vacuum tank
• Can quickly achieve 1x10-7 Torr
(lower if we pump longer)
• Has a special painted interior with low out gassing characteristics
• Water cooled vessel and support stand so that just the sample can be heated to 1250° F.
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Want to study only out gassing
• This is a study of out gassing by:– pumping on the
sample to see • how low vacuum
can be reached
• shape of the curve while pumping
– out gassing after reaching a vacuum will increase pressure
• This is not a study of suitability of these materials for:– window to air,
– gaseous hydrogen or helium, and
– to liquid hydrogen or helium
![Page 5: Al-Li 2000 series alloy out gassing Studies at IIT N. Solomey, Physics Division Philippe Nash, Material Science Division 21 Feb. 2003](https://reader036.vdocuments.mx/reader036/viewer/2022062518/56649d555503460f94a3216b/html5/thumbnails/5.jpg)
Sample PreparationSample Preparation• Six samples number 1 through 6 of various
types of Al alloys 1 in2 were machined by Ole Miss. Univ. and send to us. We do not know what sample is which alloys.
• Each sample was cleaned with Ethyl alcohol and stored in a clean tray and handled with gloves.
• The Molly Furnace was baked out for 3 days at 1200 F.
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QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.
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QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.
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Outgassing study
0.000001
0.00001
0.0001
0.001
0 20 40 60 80
Time [min.]
Pressure [torr]
Empty Sample 1Sample 2Sample 3Sample 4Sample 5Sample 6
Pump-down out-gassing study
1.E-06
1.E-05
1.E-04
1.E-03
0 20 40 60 80
Time [min.]
Pressure [torr]
Empty Sample 1Sample 2Sample 3Sample 4Sample 5Sample 6
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Studies First Conclusions:• Preliminary results are that we see a slight
difference between the samples and an empty tank.
• P. Nash suggest we consider:– Heating samples to 25% to 50% of melting point
to enhance out gassing.– Grind up the samples to small pieces making a
larger surface area to enhance out gassing.
• Put a residual gas analyzer on the vacuum pump to see what is coming off.
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Other Interest:• Our main interest is:
– Out gassing during first use of these alloys so we do not contaminated interior of accelerating cavity.
– Suitability of these new alloys for use as thin windows with liquid hydrogen or helium on other side.
• NASA has an interest in these 2000 series Al-Li alloys for radiation studies. This is also of interest to us.