Arc erosion behavior and microstructure investigations of silver-based contact materials (Englisch)

ICEC, International Conference on Electrical Contacts, 24
; 2008
  • Neue Suche nach:

The understanding of the degradation mechanisms of contact materials is a key issue for the development of new materials with enhanced durability. This can be achieved through the investigation of the microstructure modification caused by electrical arcs on the surface of contacts. In this work, the erosion behaviour of pure silver and silver based composites (AgSnO2 and AgCdO) is presented. Single breaking operations were performed with direct current. Using white light interferometry, the size of the craters on the surface as well as the volume of eroded material has been measured. By means of dual beam techniques, coupling a Focused Ion Beam (FIB) with a Scanning Electron Microscope (SEM), the microstructural modifications on and below the crater surface related to the formation of oxide layers, oxide agglomerates and pores have been investigated. In this paper, first results of the study will be shown. In this work, the authors have focused on two issues. One is the study of erosion behavior in comparison to different electrical parameters and various materials. The other is the analysis of the microstructures directly below a crater. The results can be summarized as follows: It has been be shown, that the volume transfer caused by the arc and the crater area are functions of the arc energy. The influence of the current on the arc energy is smaller than the influence of voltage. A big difference of the moved volume has been measured between the pure silver and the silver composites. This result is explainable by the influence of oxides. However no significant difference exists between both composites materials. This could be related to the low used arc energy. The performed cross sections of the composite materials have shown strong modifications of the original microstructure. These modifications have an influence on physical parameters of contact material and thereby on the switching behavior.

Wie erhalte ich diesen Titel?
TIB vor Ort

Für Benutzerinnen und Benutzer auf dem LUH Campus überprüfen wir gerne den kostenfreien Bezug.

Anfrage Verfügbarkeit LUH

Dokumentinformationen


Ähnliche Titel