Study On The Effect Of Material Composition On The Resistance To High Energy Arc Erosion Of CuW Alloys

CuW alloy is a typical pseudo alloy because copper and tungsten do not dissolve or form inermxtallie compounds.Therefore,it combines the characteristics of high melting point,high demsity,high strength,and good resistance to fusion welding of trngsten,as well as excellent ecnduetivity and thermal conductivity of copper.It is widely used as the core component of hithroltage circuit breakers-electrical contrcts.At the montent of disconnection,hith-voltage electrical contacts contain a large number of free electrons in the contact itself and surrounding media.When the external field strength is large enouth,strong ionization oeeors and high-energy are erosion oeetars.The high-energy are has a grent dertuctive effect on the contact and will prolong the time of fault circuit disconnection,causing serious damage to high-voltage trantmistion and distribution lines and circuit breakers.Therefore.it is particularly important to explore the resistance of electrical contact materials to high-energy are erosion.This artiele uses the sintering infiltration process to prepare four types of electrieal eontact maiteriats:CuW60,CuW70,CuW80,AND CuW80-Gr.The effects of the distribution ratio of Cu and W phases and the addition of graphene on the microisructure,physlcal properties,andresisiance to high-energy are erosion of CuW alloy were studied.By compating and analyzing the surface morphology,composition changer.and phase characterization of the alloy afger areerosion,the mechanism of the influence of W phase and high conductivity Cu phase on the resistance of CuW alloy to high-energy are erosion is explored.The optimal Cuand W component ratio for resistance to high-enerty are crosion is selected,providing a basis for component selection for the contact of ultra large capacity circuit breakers,At the same time,the effect of adding graphene on the high energy arc erosion resistance and friction wear performance of CuW alloy was studied,revealing the mechanism of graphene’s influence on the service performance of CuW electrical contact materials.The research results indicate that:(1)The voltage withstand strength of CuW alloys mainly depends on the intrinsic characteristics of the material,that is,the voltage withstand strength does not vary significantly while the components are in phase;As the discharge voltage gradually increases,the arcing time,discharge energy,and erosion area of the alloy all increase.Under the same discharge voltage,compared to CuW60 and CuW80 alloys,CuW70 alloy has the best comprehensive resistance to high-energy arc erosion.It is not that the higher the content of highly conductive Cu phase or ablative W phase,the better the arc erosion resistance of CuW alloy.(2)As atypical high-voltage electrical contact material,CuW alloy has high melting point,high hardness,resistance to fusion welding,and excellent high-temperature stability.The higher the content,the continuous W skeleton can be formed,which improves the strength of the alloy and significantly improves the arc erosion resistance of the alloy.As a sweating material,Cu phase can melt and evaporate,taking away a large amount of heat;At the same time,the dispersion distribution of Cu phase with lower electronic work function can significantly disperse the arc and reduce the erosion of high-temperature arc on the alloy.It is precisely due to the synergistic effect between the arc erosion resistance of W phase and the reduction of arc erosion characteristics of Cu phase on the alloy,that the arc erosion resistance of CuW alloy is significantly improved.(3)The addition of graphene increases the arc burning time and arc energy of CuW alloy.Because of its low electron work function,the dispersed graphene under the effect of external field strength can disperse the arc,avoid local concentrated erosion of CuW alloy,and improve the arc erosion resistance of CuW alloy;At the same time,the addition of graphene improves the strength of CuW alloy,reduces the friction coefficient and wear volume of the alloy,and reduces the wear of electrical contact materials.