Observation on AgSnO₂In₂O₃ molten bridge phenomena under different currents

Abstract

The electrical contact-high speed imaging experimentation system was developed to investigate the molten bridge phenomena of AgSnO₂In₂O₃ electrical contact material. The dimension of molten bridge was measured along with measurement of waveforms in the contact voltage under the load of DC 6 V (8 A to 20 A). A part of the observed results was presented as well as surface morphology and element distribution of the contacts, which showed us some interesting and new phenomena. Molten bridges and arc could exist simultaneously. The stable molten bridge was seen like cylindrical shape and then became dumbbell before rupture, the diameter and of molten bridge both increased with the increase of current. SnO₂ and In₂O₃ can restrain the transfer of Ag and play a protective role on the contact material.