Micro-arc tests for MHD electrode materials

Improving the durability of the anode for a coal-fired MHD channel is an important research subject. This paper describes the results of micro-arc tests (power arc tests) for 21 metallic and 4 ceramic electrode materials. Their arc resistances were specified by the observation of the crater formed by the pulse current. Also described are the results of splash experiments (power arc tests carried out under coal-fired MHD simulation) for TiC-coated stainless steel (TiC/SUS) electrodes. The results of the micro arc tests indicate that tungsten, W-based alloy, tantalum, molybdenum, platinum and TiC-coated stainless steel have desirable arc resistances. In the splash experiments, the TiC-coated stainless steel electrode has a more desirable arc resistance than the electrode without a TiC layer.