Effect of Microscale and Nanoscale Hybrid Boron Nitride Fillers on Arc Ablation Performance of PTFE

The high voltage circuit breaker plays an important role in the circuit. In order to extend the service life of the circuit breaker, it is necessary to have materials with excellent ablation resistance. At present, The PTFE with boron nitride (BN) is widely used to produce the nozzle of high voltage circuit breaker. With the increase of BN filler particle size, the arc ablation performance of the composite increases gradually. In order to obtain the nozzle material with excellent ablation performances, nanoscale and microscale h-BN were divided into five groups with different mass ratio, then added into PTFE to prepare five kinds of composite materials with constant BN mass fraction. To study the influence of mass ratio on the thermal conductivity and arc ablation characteristics of PTFE/BN composites, arc ablation, thermal conductivity and spectral reflectance are tested. After adding microscale and nanoscale hybrid BN, the ablation amount of the composite decreased firstly and then increased, reaching the minimum in the third group. This work indicates there is a certain proportion with the excellent performance in arc ablation characteristics. This paper offers a feasible method for the preparation of PTFE/BN high-voltage circuit breaker.