Study on Vacuum Breakdown Properties of Surface-Modified 304 Stainless Steel Electrodes Based on Fractal Theory

This paper reports on the effect of the micro-morphological characteristics of stainless steel electrodes on vacuum breakdown properties under the action of a strong electric field generated by high-power electric pulses. Using chemical passivation modification and atomic layer deposition (ALD) technology, alumina composite films were prepared on the surface of the stainless steel electrodes to reshape the surface microstructure of the electrodes. The surface morphology features of the electrodes were characterized in detail. Based on fractal theory, a fractal model based on the box dimensional method was proposed to quantitatively describe the morphological and structural characteristics of the film, and its relationship with the vacuum breakdown properties was established. The results indicated that the fractal dimension effectively reflected the complexity of the electrode morphology and could serve as a key parameter to evaluate the vacuum breakdown performance of the electrodes, which showed a negative correlation with the change tendency of the electrode breakdown threshold.