The Arc Erosion Behavior Research Of Ag-based Contacts Reinforced By Nanofiberss And Particles

As an important part of various electrical appliances,contact materials act as connecting and breaking circuits in the circuit.Silver metal oxide（Ag-MeO）contact material is currently the most widely used low-voltage contact material due to its excellent electrical conductivity,arc erosion resistance and welding resistance.Ag-SnO₂ material is the most widely used and researched low-voltage contact material.At present,the main problem of Ag-SnO₂ contacts is that SnO₂ particles tend to float on the surface of the Ag molten pool after arc ablation,resulting in larger contact resistance and temperature rise.Increase,seriously affect the life of electrical contact materials.In order to solve this problem,this topic uses the electrospinning method to prepare a trace number of CuO-doped SnO₂-nanofibers,and add it to the traditional SnO₂ particle-reinforced Ag-SnO₂ material to build a nanofibers/particle hybrid reinforced silver-based contact structure.The addition of SnO₂ fibers suppresses the floating of SnO₂particles in the molten pool,thereby improving the electrical contact performance of the Ag-SnO₂ contact material.At the same time,TiN ceramic particles have a higher melting point and high thermal stability than traditional SnO₂ particles,but TiN ceramic particles have higher electrical conductivity and semiconductor material characteristics,so the TiN particles float to the silver-based contact when the arc is broken.Point the surface.Compared with Ag-SnO₂ contact materials,Ag-TiN contacts have lower contact resistance and temperature rise.Research and development of new TiN particle-reinforced silver-based contact materials is a powerful supplement to traditional Ag-SnO₂ contacts.The research of SnO₂-nanofibers prepared by electrostatic filament method shows that the optimal heat treatment temperature of SnO₂-nanofibers membrane is 600℃for 2 hours,and the heating rate is 1℃/min.The structure of the SnO₂-nanofibers and silver powder will not be damaged after proper ball milling and mixing.The Ag-based contact material SnO₂-nanofibers prepared by SPS hot-press sintering has a uniform reinforcement phase distribution and high density.The arc erosion experiment results show that at the initial stage of make-and-break testing,the surface morphology of SnO₂ fiber/particle hybrid-reinforced silver-based contacts and pure SnO₂ particle-reinforced silver-based contacts are small,and both exhibit good arc erosion resistance;With the increase in the number of make-and-break testing times,the contact surface enhanced by pure SnO₂ particles has serious ablation,resulting in large mass loss and particles gradually floating to the surface.After 50,000 times of make-and-break testing.,the SnO₂-nanofibers reinforced contacts still have good electrical contact performance,the surface ablation morphology is complete,the mass loss is small,and the arc erosion degree of the contact surface is small,the temperature rise is low,and the contact surface is relatively low.Good electrical contact performance.The research results show that the SnO₂-nanofibers prepared by the electrospinning method has good arc erosion resistance,and it is not easy to decompose after repeated arc ablation.It can better inhibit the particle floating and reduce the mass loss of the contact.The addition of Ag-SnO₂can significantly improve the traditional Ag-SnO₂ contacts and effectively improve the electrical life and electrical contact performance of the contacts.The study found that after multiple arc ablation of Ag-TiN contact,TiN will decompose and O₂ will form TiO₂ attached to the contact surface at high temperature.With the increase of make-and-break testing.times,TiO₂ dendrites will gradually form and adhere to the contact.TiO₂ enriched area on the surface.Since the formation of TiO₂ material and the generation of TiO₂ dendrites absorb a large amount of energy in the make-and-break testing.process,it helps to extinguish the arc,and the arc erosion resistance of Ag-TiN contacts is significantly improved.With the increase of the number of breaking times,the temperature rise of Ag-TiN contacts has been greatly improved.However,due to the high thermal stability of the generated TiO₂ structure and the characteristics of semiconductor materials,it still has ability and resistance to arc erosion after 50,000 make-and-break testing times.