Arc erosion mechanism and surface characteristics of TiN particles reinforced Ag based electrical contact materials

Electrical contact materials (ECMs) are crucial for ensuring the stability and efficiency of electrical instruments and electronic devices, as they regulate current flow. As an essential component of ECMs, Ag-SnO2 composite ECMs exhibit excellent conductivity and weld resistance. However, the resistance of materials to arc erosion diminishes as the frequency of arc erosion increases. Herein, titanium nitride (TiN) particles reinforced silver (Ag) based electrical contact materials were synthesized using a combination of high-energy ball milling and spark plasma sintering (SPS) techniques. The results indicated that TiN particles reinforced Ag based electrical contact materials could strengthen the interface bonding, which can dramatically improve the microhardness (up to 145.3 HV), conductivity (up to 68.9 %IACS), density (up to 98 %) and resistance to arc erosion. After 5 x 104 times arc erosion cycles, the mass loss of the Ag-TiN contact material is 0.0125 g, representing approximately 0.19 % of the total mass. Meanwhile, the friction properties of the electric contact materials were evaluated, and the results indicated that the Ag-TiN electric contact materials exhibited superior friction resistance, with an average friction coefficient of 0.8305. Furthermore, the decomposition of TiN ceramic particles under arc energy leads to the formation of highly thermally stable titanium dioxide (TiO2) dendrites on the contact surface, which mitigates mass loss, effectively reducing arc erosion and extending the contact materials service life.