This study has been carried out to develop new cathode materials for air-plasma cutting. The consumption of Re-Y2O3 and Ru-Y2O3 electrodes was compared with that of Elf and Zr electrodes which have been widely used. Electrodes of Re including 15 to 40% Y2O3 and Ru including 10 to 35% Y2O3 showed lower rates of consumption rather than those of Hf and Zr electrodes in case of continuous life time test. Furthermore, 85Ru-15Y2O3 electrode showed a superior erosion resistance in case of periodic operating test at 25 A compared with the other electrodes.
