Non-destructive method by nonlinear ultrasonic measurements for aging characterization of silicone rubber

Silicone rubber has been widely applicated in the electrical field, especially used as insulation materials, due to its excellent physical properties. However, the performance of silicone rubber will decline with its aging process leaded by plenty of factors. There's lack of methods for overall nondestructive characterization of the aging degree of silicone rubber in use presently. In this paper, the thermal aging experiment of silicone rubber is designed, and the nonlinear coefficient of the sample is measured by nonlinear ultrasonic method during the aging process, the change of the nonlinear coefficient of the sample during the aging process is analyzed, the rule of thermal aging of silicone rubber is summarized, and the feasibility of using the nonlinear coefficient as the aging characterization of silicone rubber is discussed.