1. 03/04/2000LHC Vacuum Design Meeting Karine COUTURIER/EST-SM C17110 and C17410 coppers  Chemical composition (wt%) : copper = alloy balance Be Ni Co Fe Zr Sn Al Si Zn Cr Pb C17110 0.34 1.3 - - 0.1 0.03 - - - - - C17410 0.31 0.02 0.5 0.03 - 0.005 0.04 0.02 < 0.01 < 0.005 0.003  Thermo-mechanical treatment : C17110  TH01 = solution annealed + cold worked to 1/4 hard + precipitation hardened C17410  TH02 = solution annealed + cold worked to 1/2 hard + precipitation hardened 750 - 800 o C 300 - 400 o C Be-enriched  phase

2. 03/04/2000LHC Vacuum Design Meeting Karine COUTURIER/EST-SM Tensile properties at RT L = longitudinal direction - T = transversal direction Rp 0.2 / MPaRm / MPaA / % C17110 / TH01 506 628 24.1 C17410 / TH02 626 736 18.7

3. 03/04/2000LHC Vacuum Design Meeting Karine COUTURIER/EST-SM Tensile properties at 4.2 K L = longitudinal direction - T = transversal direction Rp 0.2 / MPaRm / MPaA / % C17110 / TH01 580 850 40.6 C17410 / TH02 740 937 37.5

4. 03/04/2000LHC Vacuum Design Meeting Karine COUTURIER/EST-SM Comparison : Tensile properties  lower yield and tensile strengths  higher elongation at breakdown

5. 03/04/2000LHC Vacuum Design Meeting Karine COUTURIER/EST-SM Comparison with C17200 copper More traditional grade with higher Be content (2 wt%) Used in LEP ring at present TH02 thermo-mechanical treatment  Tensile properties at room and low temperatures :  improved formability  Improved electrical conductivity : C17200/TH02 C17110/TH01 C17410/TH02 Total alloying (wt%) 3.2 1.77  0.943 % IACS 22-25 49.3 53.3

6. 03/04/2000LHC Vacuum Design Meeting Karine COUTURIER/EST-SM Conclusion  Advantages of C17110 and C17410 coppers in TH02 state : - higher ductility, improved formability  easier product forming  simple manufacturing process - higher electrical conductivity  improved electrical output compared to more traditional C17200 beryllium copper  Are those new coppers interesting for LHC applications ? Is Rp 0.2 value sufficient ? Is material choice still open ?  STAINLESS firm propose to visit CERN during the first week of May.

7. 03/04/2000LHC Vacuum Design Meeting Karine COUTURIER/EST-SM Two new low beryllium coppers  Description of C17110 and C17410 coppers : alloying, thermo-mechanical state.  Tensile properties at room temperature and 4.2 K.  Comparison with more traditional C17200 copper : tensile properties, electrical conductivity.  Conclusion : formability, electrical output. possible applications at CERN.