Preparation and Electrical Characteristics of Novel AgZrB2 Contact Materials

Abstract:

The novel AgZrB₂ electrical contact materials with different ZrB₂ contents were prepared by the combination method of ultrasonication, ball milling, and spark plasma sintering, and the arc erosion and material transfer behavior were investigated by the electrical contact tests. The results show that the ZrB₂ content significantly affects the arc erosion resistance of AgZrB₂ electrical contact materials. The Ag-3wt% ZrB₂ contact material presents the stable make/break-arc energy and duration, indicating the excellent arc erosion resistance. However, the increased ZrB₂ content results in higher make-arc energy and longer make-arc duration with large fluctuations of break arc energy and duration, leading to the severe arc erosion. This result suggests that the excessive ZrB₂ is not beneficial to the enhancement of arc erosion resistance. Moreover, it is found that the Ag-3wt% ZrB₂ and Ag-5wt% ZrB₂ contact materials have the same material transfer mode from anode to cathode, whereas the Ag-7wt% ZrB₂ contact material has the opposite transfer mode from cathode to anode.

Key words:Ag-based electrical contact;ZrB₂;arc erosion;material transfer