Arc erosion behavior and mechanism of AgZrO2 electrical contact materials
Yanru Qiu, Xianhui Wang, Yan Liang, Zhen Li, Yuan Fei, Lei Wang
Abstract
In this study, the novel AgZrO 2 electrical contact materials reinforced with different ZrO 2 contents were successfully fabricated by powder metallurgy . The effect of ZrO 2 content on arc erosion resistance of the AgZrO 2 electrical contact materials was investigated, and the electrical conductivity and hardness were measured, as well as the arc erosion mechanism was discussed as well. Furthermore, the properties of AgZrO 2 electrical contact material were also evaluated as compared to AgSnO 2 electrical contact material. The results show that with increase of ZrO 2 content, the hardness of AgZrO 2 electrical contact materials gradually increases, while the electrical conductivity gradually decrease. The good comprehensive properties can be achieved at 8 wt%ZrO 2 . The electrical conductivity and hardness of Ag-8 wt%ZrO 2 electrical contact material are 72.8%IACS and 77.9 HV, respectively. The AgZrO 2 electrical contact materials with less than 8 wt% exhibit lower arc energy and shorter arc duration, as well as outstanding arc erosion resistance. However, an excess ZrO 2 content causes obvious fluctuations on arc energy and duration, thereby resulting in more severe arc erosion. As compared to the Ag-8 wt%SnO 2 electrical contact material, the Ag-8 wt%ZrO 2 electrical contact material presents lower stable contact resistance, less arc energy, shorter arc duration and better interfacial bonding , thus exhibiting excellent resistance to arc erosion.