Measurements of Specific Electrical Contact Resistance Between SiC and Lead-Lithium Eutectic Alloy

Silicon Carbide (SiC) has been proposed as a possible candidate material for flow channel inserts for the dual coolant blanket concept. Here, the total electrical resistance of disks of high purity CVD SiC were measured with liquid lead-lithium eutectic (LLE) alloy melts serving as electrodes. From this data, the relative contributions of intrinsic resistivity and surface contact resistance as a function of measurement temperature was deduced. It was shown that after a relatively short period of exposure, once wetting at the interface was achieved, that contact resistance at the SiC/LLE interface was not significant. The contact resistance during initial exposure did not behave in a repeatable consistent way and appears to be affected by small variations in sample preparation. For modeling purposes, the electrical properties of an FCI can be based on the intrinsic electrical conductivity of the material and the dimensions. However, longer term operations and effects of impurities still need to be addressed.