High-speed imaging observation on molten bridges of AgNi10 electrical contact material

The electrical contact–high-speed imaging experimental system was developed to investigate the molten bridge phenomena of AgNi10 electrical contact material. The dimension of molten bridges was measured along with the measurement of waveforms in the contact voltage under the load of direct current (DC) 6 V (8–20 A) and breaking speed of 50.0 mm·s−1. A part of the observed results was presented as well as surface morphology of the contacts after electrical contact behavior, which shows some interesting and new phenomena. Molten bridges and arc could exist simultaneously. The stable molten bridge looks like cylindrical shape and then becomes needle tip at its rupture, the diameter and length of molten bridges both increase with the increase in current and the growth gradient of the diameter is larger than that of the length. The morphology and elemental distribution of the contact surface are changed by the behavior of electrical contact.