Effect of X-Ray Irradiation on Properties of Insulating Materials

Abstract

X-ray digital imaging technology can be used for visualization and nondestructive detection of power equipment, which is widely used in defect determination and anomaly detection. However, when X-ray is used for defect detection of power equipment, it remains to be investigated whether X-ray irradiation will deteriorate the properties of insulating materials or not. In this study, four kinds of insulating materials that are commonly used in power equipment, including alumina (Al₂O₃), epoxy/alumina (EP/Al₂O₃) composite material, polyether ether ketone (PEEK), and polyimide (PI), are irradiated with high-penetration and high-dose X-rays. The effects of irradiation time and atmosphere on the properties of insulating materials were studied systematically. The results show that the crystalline structure of inorganic materials and the chemical structure of organic materials are basically unchanged after X-ray irradiation. In terms of insulation properties that include dielectric property, surface flashover voltage, surface potential decay, and volume resistivity, it turns out that the insulation performance of the insulating materials tends to deteriorate after X-ray irradiation, while the degree of degradation is extremely low. In addition, the results of surface potential decay of EP/Al₂O₃ show that the X-ray irradiation would accelerate the dissipation of surface charge, which is in favor of the safety of power insulation.