Tracking and erosion resistance performance investigation on nano-sized SiO<sub>2</sub> filled silicone rubber for outdoor insulation applications

This paper discusses the tracking and erosion resistance characteristics of nano-sized SiO ₂ filled virgin and aged silicon rubber (SiR) materials under AC voltage with ammonium chloride as a contaminant as per IEC-60587 test procedures. The characteristic variations in the tracking time, weight loss and eroded depth of nano-sized SiO ₂ filled virgin and aged SIR specimens are analysed in order to evaluate the relative erosion and tracking resistance of the composites. Statistical variation of the tracking time is evaluated by Weibull analysis. The Thermo Gravimetry-Derivative Thermo Gravimetric (TG-DTG) studies are performed to understand the thermal properties of the nano-sized SiO ₂ filled SIR materials with different percentage weights (% wt) of filler. The obtained result shows that the thermal performances of nano-filled virgin and aged SIR specimens are improved when the %wt of filler is increased. The Scanning Electron Microscope (SEM) with Energy Dispersive X-ray (EDAX) and Fourier Transform Infra-Red spectroscopy (FTIR) are used to investigate the physical and chemical properties of the virgin and aged SIR composites. It is observed that the tracking and erosion resistance is improved when nano-filler concentration is increased in both the virgin and aged SIR composites. Also thermal aging slightly reduces the tracking and erosion resistance of the nano-filled SIR composites.