Construction of microgrooves on the surface of alumina ceramic insulator to enhance its flashover strength

Abstract

The fabrication method of grooves on the surface of alumina and their influence on the surface flashover characteristics of the alumina insulator were studied in this paper. To prepare grooves with a regular surface structure, the UV laser was applied to carve grooves on the surface of alumina ceramic, and dilute hydrochloric acid was used to corrode and remove the residual materials produced in the laser carving process. By adjusting the laser parameters, periodic grooves were prepared on the surface of a cylindrical alumina insulator with a groove depth of 60 µm and a groove width of approximately 50 µm on the laser spinning carving platform. Then, alumina insulators with different periods were prepared, and their vacuum surface flashover voltages were tested on a short pulsed high-voltage test platform. The test results indicated that the flashover voltages of the alumina insulators with laser carved periodic grooves were increased over 200%, and the improvement did not change much with the groove periods. A further study of the groove parameters showed that several grooves fabricated on the cathode end of the insulators were able to improve the flashover voltage of the alumina insulator to the voltage-withstand level of the fully grooved insulators.

Micropatterning of alumina tubular membranes via laser carving for enhanced direct air capture

“…14 Micropatterns on ceramic surfaces have been conducted by various techniques such as replication. 15 anodization, 16 hydrothermal methods, 17 soft lithography, 18 laser carving, [19][20][21] chemical etching, 22 or powder blasting with the help of PDMS mask. 23 Laser carving is especially useful for machining hard and/or brittle materials with high precision, excellent productivity, and surface quality.…”

Flashover Voltage of Epoxy FRP Insulators with Different Surface Roughness and Groove under Nanosecond Pulses in SF6

“…Iwata's study showed that the surface flashover voltage in the direction perpendicular to the groove structure is approximately 1.2 times larger than that in the parallel direction under the AC voltage in a vacuum [17]. Liu and Huo et al, applied the fabrication method of microgrooves on the surface of alumina and polymer insulators, and found that the method can increase the flashover voltage significantly [18,19]. Cheng et al, studied the effect of periodically grooved dielectric on extending the flashover time lag in a vacuum, and ascribed the effect to the suppression of SEEA process [20].…”