Properties of Ag-SnO2 Contact Materials for Low-Voltage Electrical Appliances with Different Doped Particle Sizes

Haitao Wang,Menglin Yang,Mei Zhang

doi:10.1155/2019/7275681

Abstract

In this paper, the relationship between additive particle size and properties of Ag-SnO2 contact materials was studied. La2O3 and Fe2O3 were selected as additives for contact materials, and the proportion of additives were determined by wettability experiment results; Ag-SnO2 contact materials were successfully fabricated by the powder metallurgy method, and the physical and electrical contact properties of Ag-SnO2 contact materials with five additive particle sizes were investigated. The results show the influence of additives on the properties of Ag-SnO2 contact materials are disparate, the contact resistance and arc energy are smaller and more stable when the additive particle size is about 500 nm. For further proving this conclusion, the arc-eroded surface morphologies of the doped AgSnO2 contact materials were investigated by scanning electron microscopy (SEM), which indicated that the properties of two kinds of Ag-SnO2 contact materials could be improved significantly by selecting appropriate additive particle size.

Highlights

Introduction e environment friendly AgSnO2 contact materials have been extensively utilized in low-voltage apparatus that attributes to their wonderful performance [1,2,3,4,5]
Research shows that the contact resistance and temperature rise of Ag-SnO2 contact materials for low-voltage electrical appliances are too high, it can be ascribed to the fact that SnO2 enriched in the contact surface will form an insulating layer after the arc extinguished, which leads to the increase of the contact resistance of Ag-SnO2 contact material
It was reported that the wettability between the second phase and silver, as one of the significant characteristics of the surface melting pool, has a vital effect on the spray resistance of the contact. e antisplash performance is improved due to the enhancement of the wettability, which contributes to the enhanced combination of molten silver and contact surface, and the reduced separation between molten silver and the second phase, maintaining the viscosity of the molten pool, reducing the splashing loss of the silver melt, resulting in the improvement of the resistance of the material to arc erosion

Summary

Introduction

Introduction e environment friendly AgSnO2 contact materials have been extensively utilized in low-voltage apparatus (such as relays, circuit breakers, contactors, etc.) that attributes to their wonderful performance [1,2,3,4,5]. E results show the influence of additives on the properties of Ag-SnO2 contact materials are disparate, the contact resistance and arc energy are smaller and more stable when the additive particle size is about 500 nm.

Results

Conclusion