Characterizing Surface Profiles of Tungsten-based Electrodes under Intense Pulsed Arcs

This paper presented the detailed results of surface profiles of tungsten-based electrodes (W-Ni-Fe and W-Cu) under 100-kA level repetitive pulsed arcs for 10, 000 times. Focusing on the surface morphology, a series of statistical parameters (surface roughness, etc.) were adopted to quantitatively characterize the features of electrode surface. Meanwhile, the evolution of those parameters in the aging process was summarized and analyzed systematically. The results indicated that the contour of the electrode changed in both general shape and micro-structure. For the macroscopic contour, the characteristic diameter of the electrode tip decayed from ~21 mm to less than 18 mm after the test. As for the micro-fluctuations (μm level), various erosion patterns were found in anode and cathode, or in W-Ni-Fe and W-Cu electrodes. Then, possible mechanisms of those phenomena were discussed. Finally, the Fast Fourier Transform (FFT) method was adopted to study the spatial pseudo-periodicity of the electrode profiles. The four materials had a rank on erosion resistance, namely, 97WNiFe>93WNiFe90WNiFe>90WCu.