Improvement of Arc Erosion Resistance of Ag–SnO ₂ Contact Materials by Reducing Molten Pool Size

The splash of molten Ag under arc erosion is the major reason for the failure of Ag‐based contact materials. Changing the size of the molten pool may manipulate the splash process and suppress the arc erosion. Herein, the size effect by fabricating a SnO ₂ network with pores smaller than the typical Ag molten pool is investigated. Silver is subsequently infiltrated into the SnO ₂ network to form Ag–SnO ₂ interpenetrating contact materials. It is found that the SnO ₂ network with small pore sizes separates the Ag matrix into smaller regions, reducing the melting volume. Compared with the particle‐dispersed one, the interpenetrating composite decreases ≈90% mass loss and temperature rise, as well as provides superior microstructure stability. This finding demonstrates a promising way to improve the arc erosion resistance of contact materials by tailoring the size of molten pool, benefiting long‐lifetime contact materials for smart grid applications.