First International Symposium on the Science and Technology of Ingot Niobium

September 22th - 24, 2010 Jefferson Lab, Newport News, USA

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CBMM worldwide presence offices and warehouses

CBMM dedicates special attention to its customers, wherever they may be around the globe.

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STANDARD FERRONIOBIUM Products for Sale

Production

CONCENTRATION REFINING FeNb VG NiNb VG NIOBIUM OXIDE HP SPECIAL OXIDES

Araxá, MG

ATR Nb METAL

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CBMM expansion plan

Expansion

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CBMM 2nd ELECTRON BEAM FURNACE Innovate, Respect, Compete

CBMM ELECTRON BEAM FURNACE

Electron Beam 01 Electron Beam 02 •Start up in 1989 •Capability – 60 ton/year •Power : 2 x 250 kW (2 guns) •Beam accelerating voltage: 35 kV •Start up in 2003 •Capability – 150 ton/year •Power : 3 x 600 kW (3 guns) •Beam accelerating voltage: 45 kV

CBMM ELECTRON BEAM FACILITIES

•Ingots from 250mm to 400mm in diameter •Lengths up to 2,000mm and weigth of 2 tonnes

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Development of High Purity Niobium Metal at CBMM

CBMM has been improving continuously its refining process to attend the demanding specifications of the market, such as high purity niobium ingots for superconductive cavities. This market has been growing up and is expected to have a high tonnage consumption during the next years. For that purpose CBMM has carried out several tests in order to optimize its process between 2008 and 2010 .

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Development of High Purity Niobium Metal at CBMM

1 st step tests with feeding rate and argon:

Ingot ingot melt Niobium Metal Feeding rate (mm/min) Argon reduction Yes/No 1 2 3 4 5 6 7 8 9 2nd 3rd 2nd 3rd 2nd 3rd 2nd 3rd 2nd 3rd 2nd 3rd 2nd 3rd 2nd 3rd 2nd 3rd normal normal normal normal normal normal reduced reduced reduced reduced normal normal reduced normal normal normal normal normal no no no no yes yes yes yes yes yes yes yes yes yes yes yes yes yes Chemical Analisys O and N reduction O H (ppm) N O (%) N (%) 318 <10

87 <10

272 <10

65 <10

307 <10

41 <10

492 <10

89

229

39

294

<10

12

<10

11

90 12

222 <10

55 <10

243 <11

53

272

57 11

12

<10

44

22

41

15

43

13

42

12

31

12

43

31

26

18

73

14

47

12

- 73 - 76 - 87 - 82 - 83 - 69 - 75 - 78 - 79 - 50 - 64 - 70 - 70 - 60 - 29 - 31 - 81 - 74

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Development of High Purity Niobium Metal at CBMM

2 nd step: remelting of 02 ingots

Ingot ingot melt Feeding rate Nb metálico Argon reduction (mm/min) Yes/No 3 5 2nd 3rd 4th 2nd 3rd 4th normal normal normal reduced reduced normal yes yes yes yes yes yes Getter Titânio (kg) Chemical Analisys O and N reduction O H N O N (ppm) (%) (%) no no no no no yes 307 <10

41 <10 21

229

2

12

39 <10 9 2

43

13 10

31

12 3

- 87 49 - 83 77 - 70 22 - 60 76 Two ingots, with the best results (test 3 and test 5), of the nine ingots produced in the first step were selected to be remelted.

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Development of High Purity Niobium Metal at CBMM 3

rd

step

To evaluate the influence of continous remelting in the purification of niobium metal ingots, the ingot 3 and 5 were remelted for the fifth • time: the feeding rate was kept the same in both ingots; • Argon reduction ; • Ti as a guetter The ingot 3 presented reduction of 62% in O and 51% in N respectively and the ingot 5 presented reduction of 33% in O and no reduction of N.

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Development of High Purity Niobium Metal at CBMM

4 th step Production of 2 ingots with low Ta content

10 11 Ingot ingot melt 2ª 3ª 4ª 5ª 6ª 2ª 3ª 4ª 5ª 6ª Feeding rate (mm/min) Nb metálico Argon reduction Yes/No Chemical Analisys Getter Titânio metali co O H N (ppm) O and N reduction O N (%) (%) normal normal normal normal normal normal normal normal normal normal yes yes yes yes yes yes yes yes yes yes no no yes yes no no no no yes yes 307

41 21 7 7

229

39 9 6 6

<10

<10 2 3 3

12

<10 2 6 6

43

13 10 7 8

31

12 3 6 5

88 67 50 0 74 54 0 0 29 74 27 0 61 45 17 0 Two ingots, with lower Ta content, were produced with the best operational condition developed during the optimizing process of the tests one, two and three.

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Development of High Purity Niobium Metal at CBMM

Chemical Analysis Zr H O N Ta

Ingot 3 5 10 11 1330 1375 704 708

W Mo

< 18 < 18 < 18 < 18 < 50 < 50 < 50 < 50

Hf

< 25 < 25 < 25 < 25

Be

< 1 < 1 2 < 1 < 7 < 7 < 7 < 7

Fe

< 10 < 10 < 10 < 10

Ni

< 20 < 20 < 20 < 20

Cr ppm

< 10 < 10 < 10 < 10

Al

< 10 < 10 < 10 < 10

Ti Si

< 13 < 13 < 13 < 13 < 20 < 20 < 20 < 20 < 1 7,1 < 1 5,4 < 6 < 6 < 6 < 6 < 3 3 < 3 < 3

Ingot 12 Mechanical Properties Tantalum content com m ercial grade Ta > 1000 ppm 3rd m elting Higher Strenght (kgf)

1725 1275 1812

Resistante Lim it (kgf/m m ²)

13,97 10,23 14,62

Yield Strength lim it load flow (kgf/m m ²)

2,71 2,13 2,87

(kgf)

335 265 355

Elongation (%)

40,66 47,86 30,74

C Elongation (kgf/m m ²)

693,75 812,28 606,55

S

<30 <30 <30 <30 <10 <10 < 10 < 11

3 11 13 com m ercial grade Ta > 1000 ppm 5th m elting

1031 1082 1029

Reactor Grade Ta < 1000 ppm 6th m elting Reactor Grade Ta < 1000 ppm 3rd m elting

1013 1001 965 1237 1624 1802 8,43 9,03 8,21 8,24 7,99 7,85 11,03 13,40 14,61 1,68 1,67 1,6 1,55 1,56 1,63 2,18 2,6 2,92 205 200 200 190 195 200 245 315 360 48,94 85,64 80,86 66,52 84,6 65,9 35,32 33,8 45,92 578,09 976,92 587,49 545,78 525,29 603,51 547,14 789,38 561,56

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Development of High Purity Niobium Metal at CBMM

GDMS

To confirm if there is any residual element in niobium ingots produced by CBMM which can interfere in its quality, CBMM performed GDMS analysis of the ingots 3,5,10 and 11 after the last melting. Seventy seven elements, in each ingot, were analyzed though this technique and just three of these elements (O,N and Ta) presented values higher than 2 ppm. Element N O Ta 3 ~ 2.5

~ 11 910 Ingot 5 10 Concentration [ppm wt] ~ 2.5

~ 11 1200 ~ 2.6

~ 8.5

530 11 ~ 1.9

~ 4.7

570

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Development of High Purity Niobium Metal at CBMM

Final Remarks

Aiming at producing high purity niobium metal for particular purposes, such as SRF cavities, CBMM produced special ingots under controlled processing conditions from fourth to sixth melt. As a result, high purity niobium ingots with oxygen, nitrogen, hydrogen and carbon contents lower than 10 ppm were obtained in most of the ingots. Considering these results CBMM confirm the high quality of its niobium metal and conclude that this material can be used as a mother material for special applications, such as SRF cavities, preventing from excessive extra work such as further remelting and thermomechanical processing

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Thank You!

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