insulaonof0bi2212superconduc4ng0wire0 quick tips(--this section does not print--) this powerpoint...

1
RESEARCH POSTER PRESENTATION DESIGN © 2012 www.PosterPresentations.com Bismuth strontium calcium copper oxide, or Bi 2 Sr 2 CaCu 2 O 8+x (Bi-2212) is a high-temperature superconductor very promising in applications for high field (~30 T) superconducting magnets. For Bi-2212 wire to function in these magnets it must be coated by a thin layer of strongly-adhered insulation capable of both preventing the magnets from short-circuiting and withstanding the heat treatment of Bi-2212 at 890˚C in an oxygen environment. This is accomplished by coating the bare wires in a solution of a metal oxide power (in this case either titanium or aluminum), organic solvents (ethanol, m-xylene), and other organic binders and plasticizers. [1] The new insulation is then tested for its ability to adhere to the wire when scratched. I will present information gathered in the preparation of insulation for Bi-2212 superconducting wire. Introduc4on The temperature along the wire may be significantly different from the set point of the furnace. This needs to be calibrated before samples of wire can be insulated. Bi-2212 heat treatment takes nearly 4 days. For the testing of insulation properties the heat treatment may be shortened. These trials were run to establish a new schedule for heating wire. Heat treatments A, B, and C were performed on Bi-2212 wire with TiO 2 based insulation The samples produced using schedule C were very brittle and did not adhere well to the wires. Schedule B is sufficient to heat treat samples for insulation property studies. This shortens the HT time by a factor of two. Experimental Condi4ons Alumina Slurry Composi0on CONCLUSION A significant difference in temperature between furnace set point and the actual temperature experienced by the wire was discovered and calibrated. The heat treatment of wires meant to test insulation has been shortened to roughly half of the heat treatment time for Bi-2212. Alumina slurry recipe has been improved by using considerably more H-5 binders. Scratch test results show that our insulation meets or exceeds the durability of commercial nGimat samples. REFERENCES [1]. Richard E. Mistler, Eric R. Twiname, Tape Casting: Theory and Practice, Wiley-American Ceramic Society, 2000. [2]. Hom Kandel, J. Lu, J. Jiang, M. Matras, P. Chen, N. Craig, Y. Viouchkov, B. Best, U.P. Trociewitz, E. E. Hellstrom, and D. C. Larbalestier, “Development of Thin Ceramic Coating in Bi 2 Sr 2 CaCu 2 O 8-x (Bi-2212) Round Wire”, Presentation at MT-23 conference, Boston, July, 2013. ACKNOWLEDGEMENT Much appreciation to Jun Lu, Hom Kandel, The Center for Integrating Research and Learning, and The National High Magnetic Field Laboratory for all of the support throughout the course of this program. This project was sponsored by NSF DMR1157490 These tests show that the strength of the insulation of wires coated at NHMFL is at least comparable to that of commercially available samples (nGimat). Samples coated in TiO 2 are significantly more scratch-resistant than commercially available options. These tests are performed to quantify statements about the strength of adherence between insulation and wire. They involve attaching a bare section of wire to lead A, adjusting the weight, and sliding the wire back and forth under the scratching implement until coating failure occurs. Samples : Ceramic slurry : Slurry mixing : Reel to reel insulation : Heat treatment : Scratch test : Diameter : Computer setup Cu, Ag and Bi-2212 wire (0.8-1.0 mm diameter) TiO 2 , Al 2 O 3 based. See compositions in table 1 Ball milling with .25” ZrO 2 media. See Fig. 1 Small Mellen furnace in air. Modified Taber tester (Fig. 7) Digital micrometer National Instruments CompactDAQ-9174 Insulation with TiO 2 powder is successful. The next step is determining whether another ceramic powder can also be used. This was done by experimenting using Al 2 O 3 powder with increasing H-5 content. Scratch Tes0ng Heat Treatment Schedule Furnace Calibra0on 1 Department of Chemistry, Harvard University, Cambridge, Ma 02138 2 Na/onal High Magne/c Field Laboratory, Tallahassee, Fl 32310 Breshawn Best 1 , Jun Lu 2 , Hom Kandel 2 Insula4on of Bi2212 Superconduc4ng Wire Furnace Cover A Insula/on machine Fume Hood Furnace Cover B Furnace A Furnace B Control Panel Payoff Spool Dip Tank A Dip Tank B Takeup Spool Fig. 1 Fig. 3 Temperature measured on the wire along the furnace. TC* aWached NI TC* input Furnace TC* Fig. 2 Furnace calibra/on setup. The wire speed is 0.6 m/min *Type K Thermocouple There is a considerable difference between furnace set point and wire temperature (~100˚C). A cover is necessary to maintain temperature when heating green samples of wire. Sample Applied load (grams) Number of scratches before coa4ng failure Al 2 O 3 (15 wt.% H5) 50 83 100 5 TiO 2 50 232 100 40 nGimat 50 75 100 20 Fig. 4 Three different heat treatment schedules used. TiO 2 Wt (grams) wt. % TiO 2 18 16.3 Polyvinyl Butryl (PVB) 6 5.4 Ethanol 42 38.1 xylene 42 38.1 H5 1.2 1.1 Butyl benzoyl pthalate 0.5 0.5 polybutylene glycol 0.5 0.5 Al 2 O 3 insulation adhesion property improves with H-5 content. At 15% H-5, the adhesion is satisfactory. Fig. 7 Scratch test setup 0 100 200 300 400 500 600 700 800 900 1000 0 10 20 30 40 50 60 70 T (C) Time (hours) A B C Table II. Scratch test results Table I. Recipes of coa/ng slurry Mul/meter Lead A Lead B Weight Sample Site of wire aWachment Scratching implement 0 50 100 150 200 250 0 50 100 150 Temp. (C) Distance (cm) Set pt. 300˚C, Covered Set pt. 250˚C, Covered Set pt. 200˚C, Covered Set pt. 200˚C, Uncovered boWom of furnace top of furnace Al 2 O 3 C Wt (grams) wt. % Al 2 O 3 18 14.2 Polyvinyl Butryl (PVB) 6 4.7 Ethanol 42 33.1 xylene 42 33.1 H5 18 14.2 Butyl benzoyl pthalate 0.5 0.4 polybutylene glycol 0.5 0.4 Al 2 O 3 B Wt (grams) wt. % Al 2 O 3 18 14.9 Polyvinyl Butryl (PVB) 6 5.0 Ethanol 42 34.7 xylene 42 34.7 H5 12 9.9 Butyl benzoyl pthalate 0.5 0.4 polybutylene glycol 0.5 0.4 Al 2 O 3 A Wt (grams) wt. % Al 2 O 3 18 15.7 Polyvinyl Butryl (PVB) 6 5.2 Ethanol 42 36.5 xylene 42 36.5 H5 6 5.2 Butyl benzoyl pthalate 0.5 0.4 polybutylene glycol 0.5 0.4 7 μm Fig. 5 Sample of 5 wt.% H5 coa/ng Fig. 6 Sample of 15 wt.% H5 coa/ng Fig. 9 Crosssec/on of insulated 1.0mm Bi2212 wire [2] Fig. 8 Microscopic view of the Al 2 O 3 coated wire before scratch tes/ng. [2]

Upload: others

Post on 05-Jul-2020

1 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: Insulaonof0Bi2212Superconduc4ng0Wire0 QUICK TIPS(--THIS SECTION DOES NOT PRINT--) This PowerPoint 2007 template produces a 36x48 inch professional poster. You can use it to create

QUICK DESIGN GUIDE (--THIS SECTION DOES NOT PRINT--)

This PowerPoint 2007 template produces a 36x48 inch professional poster. You can use it to create your research poster and save valuable time placing titles, subtitles, text, and graphics. We provide a series of online tutorials that will guide you through the poster design process and answer your poster production questions. To view our template tutorials, go online to PosterPresentations.com and click on HELP DESK. When you are ready to print your poster, go online to PosterPresentations.com. Need Assistance? Call us at 1.866.649.3004

Object Placeholders

Using the placeholders To add text, click inside a placeholder on the poster and type or paste your text. To move a placeholder, click it once (to select it). Place your cursor on its frame, and your cursor will change to this symbol Click once and drag it to a new location where you can resize it. Section Header placeholder Click and drag this preformatted section header placeholder to the poster area to add another section header. Use section headers to separate topics or concepts within your presentation. Text placeholder Move this preformatted text placeholder to the poster to add a new body of text. Picture placeholder Move this graphic placeholder onto your poster, size it first, and then click it to add a picture to the poster.

RESEARCH POSTER PRESENTATION DESIGN © 2012

www.PosterPresentations.com

Student discounts are available on our Facebook page. Go to PosterPresentations.com and click on the FB icon.

QUICK TIPS (--THIS SECTION DOES NOT PRINT--)

This PowerPoint template requires basic PowerPoint (version 2007 or newer) skills. Below is a list of commonly asked questions specific to this template. If you are using an older version of PowerPoint some template features may not work properly.

Template FAQs

Verifying the quality of your graphics Go to the VIEW menu and click on ZOOM to set your preferred magnification. This template is at 100% the size of the final poster. All text and graphics will be printed at 100% their size. To see what your poster will look like when printed, set the zoom to 100% and evaluate the quality of all your graphics before you submit your poster for printing. Modifying the layout This template has four different column layouts. Right-click your mouse on the background and click on LAYOUT to see the layout options. The columns in the provided layouts are fixed and cannot be moved but advanced users can modify any layout by going to VIEW and then SLIDE MASTER. Importing text and graphics from external sources TEXT: Paste or type your text into a pre-existing placeholder or drag in a new placeholder from the left side of the template. Move it anywhere as needed. PHOTOS: Drag in a picture placeholder, size it first, click in it and insert a photo from the menu. TABLES: You can copy and paste a table from an external document onto this poster template. To adjust the way the text fits within the cells of a table that has been pasted, right-click on the table, click FORMAT SHAPE then click on TEXT BOX and change the INTERNAL MARGIN values to 0.25. Modifying the color scheme To change the color scheme of this template go to the DESIGN menu and click on COLORS. You can choose from the provided color combinations or create your own.

©  2013  PosterPresenta/ons.com          2117  Fourth  Street  ,  Unit  C          Berkeley  CA  94710          [email protected]  

Bismuth strontium calcium copper oxide, or Bi2Sr2CaCu2O8+x (Bi-2212) is a high-temperature superconductor very promising in applications for high field (~30 T) superconducting magnets. For Bi-2212 wire to function in these magnets it must be coated by a thin layer of strongly-adhered insulation capable of both preventing the magnets from short-circuiting and withstanding the heat treatment of Bi-2212 at 890˚C in an oxygen environment. This is accomplished by coating the bare wires in a solution of a metal oxide power (in this case either titanium or aluminum), organic solvents (ethanol, m-xylene), and other organic binders and plasticizers.[1] The new insulation is then tested for its ability to adhere to the wire when scratched. I will present information gathered in the preparation of insulation for Bi-2212 superconducting wire.

Introduc4on  

The temperature along the wire may be significantly different from the set point of the furnace. This needs to be calibrated before samples of wire can be insulated. Bi-2212 heat treatment takes nearly 4 days. For the testing of insulation properties the heat treatment may be shortened. These trials were run to establish a new schedule for heating wire. Heat treatments A, B, and C were performed on Bi-2212 wire with TiO2 based insulation •  The samples produced using schedule C were very brittle and did not

adhere well to the wires. Schedule B is sufficient to heat treat samples for insulation property studies. This shortens the HT time by a factor of two.

Experimental  Condi4ons  

Alumina  Slurry  Composi0on  

CONCLUSION  

•  A significant difference in temperature between furnace set point and the actual temperature experienced by the wire was discovered and calibrated.

•  The heat treatment of wires meant to test insulation has been shortened to roughly half of the heat treatment time for Bi-2212.

•  Alumina slurry recipe has been improved by using considerably more H-5 binders.

•  Scratch test results show that our insulation meets or exceeds the durability of commercial nGimat samples.

REFERENCES  [1]. Richard E. Mistler, Eric R. Twiname, Tape Casting: Theory and Practice, Wiley-American Ceramic Society, 2000. [2]. Hom Kandel, J. Lu, J. Jiang, M. Matras, P. Chen, N. Craig, Y. Viouchkov, B. Best, U.P. Trociewitz, E. E. Hellstrom, and D. C. Larbalestier, “Development of Thin Ceramic Coating in Bi2Sr2CaCu2O8-x (Bi-2212) Round Wire”, Presentation at MT-23 conference, Boston, July, 2013.

ACKNOWLEDGEMENT  Much appreciation to Jun Lu, Hom Kandel, The Center for Integrating Research and Learning, and The National High Magnetic Field Laboratory for all of the support throughout the course of this program. This project was sponsored by NSF DMR1157490

•  These tests show that the strength of the insulation of wires coated at NHMFL is at least comparable to that of commercially available samples (nGimat).

•  Samples coated in TiO2 are significantly more scratch-resistant than commercially available options.

These tests are performed to quantify statements about the strength of adherence between insulation and wire. They involve attaching a bare section of wire to lead A, adjusting the weight, and sliding the wire back and forth under the scratching implement until coating failure occurs.

•  Samples:

•  Ceramic slurry:

•  Slurry mixing: •  Reel to reel insulation: •  Heat treatment: •  Scratch test: •  Diameter: •  Computer setup

•  Cu, Ag and Bi-2212 wire (0.8-1.0 mm diameter)

•  TiO2, Al2O3 based. See compositions in table 1

•  Ball milling with .25” ZrO2 media. •  See Fig. 1 •  Small Mellen furnace in air. •  Modified Taber tester (Fig. 7) •  Digital micrometer •  National Instruments

CompactDAQ-9174

Insulation with TiO2 powder is successful. The next step is determining whether another ceramic powder can also be used. This was done by experimenting using Al2O3 powder with increasing H-5 content.

Scratch  Tes0ng  

Heat  Treatment  Schedule  

Furnace  Calibra0on  

1Department  of  Chemistry,  Harvard  University,  Cambridge,  Ma  02138  2Na/onal  High  Magne/c  Field  Laboratory,  Tallahassee,  Fl  32310  

Breshawn  Best1,  Jun  Lu2,  Hom  Kandel2  Insula4on  of  Bi-­‐2212  Superconduc4ng  Wire  

Furnace  Cover  A  

Insula/on  machine  

Fume  Hood   Furnace  

Cover  B  

Furnace  A  

Furnace  B  

Control  Panel  

Pay-­‐off  Spool  

Dip  Tank  A  

Dip  Tank  B  

Take-­‐up  Spool  

Fig.  1  

Fig.  3  Temperature  measured  on  the  wire  along  the  furnace.    

TC*  aWached  

NI  TC*  input  

Furnace  TC*  

Fig.  2  Furnace  calibra/on  setup.  The  wire  speed  is  0.6  m/min  *Type  K  Thermocouple  

•  There is a considerable difference between furnace set point and wire temperature (~100˚C).

•  A cover is necessary to maintain temperature when heating green samples of wire.

Sample   Applied  load  (grams)  

Number  of  scratches  before  coa4ng  failure  

Al2O3  (15  wt.%  H-­‐5)   50   83  100   5  

TiO2   50   232  100   40  

nGimat   50   75  100   20  

Fig.  4  Three  different  heat  treatment  schedules  used.  

TiO2   Wt  (grams)   wt.  %  TiO2   18   16.3  Polyvinyl  Butryl  (PVB)   6   5.4  Ethanol   42   38.1  xylene   42   38.1  H-­‐5   1.2   1.1  Butyl  benzoyl  pthalate   0.5   0.5  polybutylene  glycol   0.5   0.5  

•  Al2O3 insulation adhesion property improves with H-5 content. •  At 15% H-5, the adhesion is satisfactory.

Fig.  7  Scratch  test  setup  

0  

100  

200  

300  

400  

500  

600  

700  

800  

900  

1000  

0   10   20   30   40   50   60   70  

T  (C)  

Time  (hours)  

A  

B  

C   Table  II.  Scratch  test  results  

Table  I.  Recipes  of  coa/ng  slurry  

Mul/meter  

Lead  A  Lead  B  

Weight  

Sample  

Site  of  wire  aWachment    

Scratching  implement    

0  

50  

100  

150  

200  

250  

0   50   100   150  

Temp.  (C

)  

Distance  (cm)  

Set  pt.  300˚C,  Covered  Set  pt.  250˚C,  Covered  Set  pt.  200˚C,  Covered  Set  pt.  200˚C,  Uncovered  

boWom  of  furnace  

top  of  furnace  

Al2O3  C   Wt  (grams)  wt.  %  Al2O3   18   14.2  Polyvinyl  Butryl  (PVB)   6   4.7  Ethanol   42   33.1  xylene   42   33.1  H-­‐5   18   14.2  Butyl  benzoyl  pthalate   0.5   0.4  polybutylene  glycol   0.5   0.4  

Al2O3  B   Wt  (grams)  wt.  %  Al2O3   18   14.9  Polyvinyl  Butryl  (PVB)   6   5.0  Ethanol   42   34.7  xylene   42   34.7  H-­‐5   12   9.9  Butyl  benzoyl  pthalate   0.5   0.4  polybutylene  glycol   0.5   0.4  

Al2O3  A   Wt  (grams)  wt.  %  Al2O3   18   15.7  Polyvinyl  Butryl  (PVB)   6   5.2  Ethanol   42   36.5  xylene   42   36.5  H-­‐5   6   5.2  Butyl  benzoyl  pthalate   0.5   0.4  polybutylene  glycol   0.5   0.4  

7  μm  

Fig.  5  Sample  of  5  wt.%  H-­‐5  coa/ng  

Fig.  6  Sample  of  15  wt.%  H-­‐5  coa/ng  

Fig.  9  Cross-­‐sec/on  of  insulated  1.0mm  Bi-­‐2212  wire[2]  

Fig.  8  Microscopic  view  of  the  Al2O3-­‐coated  wire  before  scratch  tes/ng.[2]