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 C C < 0.01 <  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 o C o C Be-enriched  phase

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 / TH C17410 / TH

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 / TH C17410 / TH

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

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%)  % IACS

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.

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.