Preparation and Arc Erosion Behavior of Novel Ag-TiN Electrical Contact Materials

The titanium nitride (TiN) ceramic particles exhibit high thermal stability and electrical conductivity characteristics, making them highly suitable for replacing the traditional tin dioxide (SnO₂) particles in silver (Ag)-based electrical contact materials. In this study, novel Ag-TiN electrical contact materials are prepared using high-energy milling combined with spark plasma sintering (SPS) technology. Ag-TiN contact materials exhibit a high hardness of 146.57 HV and an electrical conductivity of 71.62 pct IACS. The surface morphology of the Ag-TiN samples is analyzed using scanning electron microscopy (SEM) and laser confocal scanning (LCS) after arc erosion testing. The testing results show that the microstructure of the novel Ag-TiN contact materials is uniform and compact, with TiN ceramic particles uniformly dispersed in the silver matrix. When arc erosion occurs, the splashing of molten Ag is minimal, and the amount of mass loss is lower compared to traditional Ag-SnO₂ materials. The arc erosion mechanism of Ag-TiN materials is that the Ti-N triple bond in TiN breaks during the arc erosion process, absorbing the arc energy to extinguish it. The TiN ceramic particles decompose due to the arc energy and form high thermally stable titanium dioxide (TiO₂) dendrites on the contact surface, effectively reducing arc erosion and improving the resistance of the contact materials.