Influence of WO3 addition on the material transfer behavior of the AgTiB2 contact material

Abstract

To clarify the effect of WO3 addition on the electrical performance of Ag-4wt.%TiB2 contact material, each contact pair was made 20,000 operations at 12 V, 29 A for the Ag-4wt.%TiB2 contact materials without and with WO3 addition. The morphology and chemical composition of arc eroded contact surface were characterized by scanning electron microscope and energy dispersive spectrometer, and the mass change before and after electrical contact test was determined as well. The results show that WO3 addition not only decreases the arc duration and arc energy, but also changes the arc erosion characteristics and material transfer mode. For the Ag-4wt.%TiB2 contact material without WO3 addition, the material transfer occurs from cathode to anode. However, it has an opposite change for the Ag-4wt.%TiB2 contact material with WO3 addition. Furthermore, WO3 addition can prevent the formation of cracks on the eroded surface.