Interlaboratory Test on Thermophysical Properties of the ITER Grade Heat Sink Material Copper–Chromium–Zirconium

Abstract

Copper-chromium-zirconium (CuCrZr) is a commercially available, precipitationstrengthened alloy. The combination of its good thermal conductivity and mechanical strength at low and moderate temperatures made it of interest for use as heat sink material in high heat flux components in actual and future fusion facilities. Its drawback is the microstructural modification and thereby particularly the loss of mechanical strength at temperatures above 500 °C. This limits allowable operational temperatures and also limits the temperature range in which cyclic and reproducible measurements of thermophysical properties can be performed. These difficulties and the international significance of the material makes it an excellent study object for an interlaboratory test of several independent European thermophysical laboratories in which the quality and comparability of thermophysical measurements were determined. The main outcome of this study is that the different laboratory data are in good agreement providing maximum deviations of ~ 5 % for dilatometry, ~ 2 % for DSC measurements and up to 10 % for thermal diffusivity measurements. In addition to the determined high reproducibility within the particular thermo-physical laboratories, it was found that the average thermal conductivity of CuCrZr produced in a certain compositional range is identical and within a small scatter band.

Development of the material property handbook and database of CuCrZr

“…Pintsuk et al [40] have reported a thorough investigation on the thermo-physical properties, namely "Interlaboratory tests", where eight European laboratories and a company Netzsch as an external reference laboratory have took part in, to perform thermo-physical tests on specimens from the same batch of material. The material for this "Interlaboratory tests" was taken from a bar material (35×35×1000mm 3 ) produced by the company Zollern/Laucherthal [41].…”

“…7 Thermal conductivities versus temperatures. [1,14,29,40,42,43] Fig. 7 shows average thermal conductivity values as well as values from various laboratories in the "Interlaboratory tests".…”

“…Data points and curves from other sources are also shown in this diagram. Pintsuk et al [40] have also reported another investigation campaign "Arbeitskreis Thermophysik" (AK), where the thermal conductivity of the same material have been measured. These values from AK are also shown in Fig.…”

Numerical Modeling of Subcooled Flow Boiling and Heat Transfer Enhancement: Validation and Applicability to Fusion Reactor Target Design

“…The divertor was simulated at both 10MW/m 2 and 20MW/m 2 as well as investigating the influence of the performance with and without tape as well as with increased twist ratio. Each material within the system has its own operating limit and for the CuCrZr pipe this limit is 773K [58].…”

Thermal behavior of the ZrB2 skeleton infiltrated with Cu and CuCrZr alloy

“…This might happen because after infiltration, it was probably in the unstable state—either in a homogenized or partially aged state. The fully homogenized alloy shows the RT thermal conductivity at the level of 170 W/m K 30 and typical aged one has the conductivity in the range of 290–330 W/m K. 30,39 The microstructure remains homogenized only in the case if water quenching (cooling speed of 90°C/s) is applied after homogenization treatment. Our CuCrZr alloy was cooled certainly at a smaller speed that is estimated to 3–5 °C/s and it resulted to not perfectly homogenized state, although, precipitates were not observed.…”