Big science (accelerators, light sources, public fusion)Fusion, private
Why it wins
Copper conductivity with real mechanical strength that survives brazing and bake cycles: photon absorbers, divertor heat-sink tubes, collimator cooling.
Why not the alternative
Pure copper loses all strength annealed; stainless cannot evacuate the heat flux.
Watch out
CuCrZr needs controlled heat-treatment windows; GlidCop is hard to weld.
Properties
The values below are candidate: compiled from the sources named, not yet individually validated.
Provisional provenance: CERN Accelerator School, vacuum and materials proceedings; ASM Handbook: properties, corrosion, heat treatment; CERN vacuum group compilations and coating programme.
Wet cleaning
Recipe
as OFE: degrease, DI, mild bright dip, ultrapure rinse
Forbidden
aggressive etch attacks the Cr-Zr precipitates and the alumina dispersion
Limit
keep any thermal step below the ageing temperature, or re-age
Vacuum and outgassing
Outgassing, unbaked (10 h)
1e-9 mbar·L/s/cm²
Outgassing, baked
5e-12 mbar·L/s/cm²
Vapour pressure
negligible
Temperature
Bake, assembled
450 °C
Vacuum degas
600 °C
Braze / H2 firing
980 °C
Metallurgical limit
CuCrZr ageing 460–500 °C; GlidCop does not recrystallise
Thermal
CTE
17 ppm/K
Thermal conductivity
320 CuCrZr, 365 GlidCop W/m·K
Specific heat
390 J/kg·K
Emissivity
0.05 polished
Melting / softening
1070–1083 °C
Mechanical
Strength
300–400 ys MPa
Tensile
450–500 MPa
Elongation
12–15 %
Young's modulus
130 GPa
Hardness
120–140 HV
Density
8.9 g/cm3
Electrical and magnetic
Relative permeability
~1.0
Resistivity
2.1 µΩ·cm
Engineering
Corrosion
as copper
Joining
brazes; GlidCop keeps its strength through the cycle
Process notes
GlidCop is not fusion-weldable in the usual sense
Availability and cost
to order; GlidCop single source
Grades
CuCr1Zr (C18150), ITER-grade IG
heat sink tubes and RF: strength depends on the exact solution-age window