Electrical Contact Performance Of The Reaction Synthesis Of Silver Tin Oxide Materials

AgSnO₂ contact material is the most promising electrical contact material,as in the electrical switch connected to the circuit and breaking device,which switches the safe operation of electrical appliances play a decisive role.So the study of electrical contact materials AgSnO₂ performance is very important.This paper studies the true strain wereε₁=5.9,ε₂=11.7,ε₃=17.6 of AgSnO₂ Contact Materials which was made by Reactive Synthesis,when under DC,resistive load conditions of electrical contact properties,then use the Molecular Dynamics method to calculate and simulate the atomic motion in the melting pool because of arc erosion.The experimental results show that the RS-AgSnO₂ has good arc erosion resistance properties when working under 18V,5A-25A conditions,the material mass change less than 120ng per-time,while the mass change would less than 50ng per-time when the conditions change to 8.5V,4A-14A.Under the 18V,and the current less than 20A working conditions,the RS-AgSnO₂ has good welding resistance performance.But once the current value is more than 20A,the welding resistance properties would declined markedly.RS-AgSnO₂ contact material mass transfer including two ways,anode transfer and cathode transfer.Both of the two ways would happen under the 18V,5A-30A working conditions.And the critical current condition is the determining factor of the way of material transfer.The more the true train is,the less critical current value is.But when the RS-AgSnO₂ contact material works under 8.5V,4A-14A conditions,the single material transfer mode is cathode transfer,and the mass change is little.As the break-close frequencies were 0.8HZ,1.0HZ,1.2HZ conditions,the RS-AgSnO₂ contact material(ε₃=17.6)transfer mode including anode transfer and cathode transfer, and material transfer reversal of the way in which the critical current value unanimously for the 16A.With frequency increasing,the anode mass loss of RS-AgSnO₂ contact material is significant increase,and the mass increases in the quality of cathode contacts gradually reduced,resulting in a total mass loss of contact shows an increasing trend.The SEM characteristics of RS-AgSnO₂ contact material after arc erosion performance the uplift and pockmarks,pores,cracks,melting beads and reticular structure.These indicated the contacts surface had molten during electric-contacts.The network structure is the result of arc erosion.With the EDS results,it's sure that the mass loss during cathode transfer is more serious than during anode transfer process.Combine the Molecular Dynamics calculation results with the experimental results,it shows that when the contacts materials surface temperature is between the melting point of silver and the melting point of tin oxide,the particle reunion of tin oxide particles in the pool were dispersed into smaller dissociation reunion particles.Thereby the viscosity of the RS-AgSnO₂ melting pool would increase.And this is one reason of why the RS-AgSnO₂ contact material has low material transfer performance.As the temperature increases,when the temperature of melting pool is higher than the sublimation temperature of silver,silver vaporization and tin oxide decomposition will occur,both of the two processes need energy consumption,it would consume arc energy. And the extinguished arc is an important factor to reduce the transfer of materials.