Zirconium Copper - a New Material for Use at Low Temperatures?
- School of Physics and Astronomy, Cardiff University, Cardiff, 5 The Parade, Cardiff, CF24 3YB (United Kingdom)
Cryogenic instruments usually require components with high thermal conductivity. Pure (non alloyed) copper offers very high conductivity, but is soft and not thus always suitable structurally. High conductivity beryllium copper (BeCu) alloys are a common choice when copper is unsuitable since they offer a good compromise between hardness and thermal conductivity. These alloys contain a small (<1%) amount of beryllium (along with a few percent of nickel or cobalt), with strength being obtained by precipitation hardening. An alternative precipitation hardened copper alloy is C15000 zirconium copper (ZrCu), which contains < 0.2% zirconium with the remainder being copper. This material does not seem to be generally used in cryogenic systems, though hardness and strength are comparable to BeCu. Moreover, the lower impurity content suggests that the thermal conductivity should be higher than for BeCu. I present residual resistivity measurements suggesting that ZrCu does indeed possess considerably higher conductivity than BeCu (19 Wm-1K-1 at 1 K compared to approximately 2 Wm-1K-1), and should therefore be a very useful material. A method is given for extrapolating the low temperature thermal conductivity values to temperatures up to 300 K; good agreement is seen with room temperature data-sheet values. This extrapolation method is shown to also be applicable to BeCu and thus presumably other dilute copper alloys, and is used to give recommended values for coin silver and various BeCu alloy types, including C17510 and C17200.
- OSTI ID:
- 20877543
- Journal Information:
- AIP Conference Proceedings, Vol. 850, Issue 1; Conference: LT24: 24. international conference on low temperature physics, Orlando, FL (United States), 10-17 Aug 2005; Other Information: DOI: 10.1063/1.2355360; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Method and apparatus for the management of hazardous waste material
Fracture testing and performance of beryllium copper alloy C17510