Study On Preparation, Microstructure And Performance Of Graphene Modified CuW80 Alloy As Contact Materials

CuW80 electric contacts are widely used in SF6 circuit breakers due to their excellent mechanical wear resistance and arc ablation resistance.However,the current CuW80 contacts can no longer meet the requirements of the new SF6 circuit breaker "no maintenance within the actual engineering life cycle".Therefore,we need to optimize the current electrical contact materials.It's an urgent problem to improve the resistance of mechanical wear and arc ablation in the case of the other performance basic unchanged.Graphene has excellent electrical and mechanical properties due to its unique crystal structure.It will provide new research methods and ideas for better properties of current SF6 high-voltage circuit breaker's contact materials by using the prominent properties of graphene to modified the metal matrix composites.In this paper,the current uhv SF6 circuit breaker contact materials service damage behavior is analyzed,and according to the theory of more than permeability and effective medium theory for graphene modified CuW80 composition design of contact materials.Using hydraulic two-way suppression of the Cu W contact materials prepared by the skeleton of billet,the induction of copper powder content and the influence law of skeleton for suppressing pressure billet density,thus guiding CuW80 contactor material preparation.Through the induction of aluminized copper powder,activated sintering permeability and presintering tungsten skeleton of molten infiltration and exploration on the methods,such as,and through adding graphene,on modification,active CuW80 electrical contact materials by SEM,XRD,metallographic microscope,etc.The material microstructure were characterized.In electrical contact in the density,hardness,electrical conductivity,bending strength and basic performance index with the national standard GB/T8320-2003 "silver copper tungsten and tungsten electrical contact CuW80 alloy materials required by the performance index of fairly,on the basis of further design and improve current CuW80 contact arc ablation resistance of material and mechanical wear resistance.Finally through the characterization of microstructure,mechanical and physical performance test,performance test and service with our country current of high voltage circuit breaker with CuW80 contact materials,summarizes the microstructure and mechanical and physical properties of contact material graphene content and the influence of service performance mechanism.The addition of graphene can improve the microstructure uniformity of CuW80 contacts to a certain extent and significantly improve the conductivity of materials.The density and flexural strength of graphene modified CuW80 contacts prepared by copper powder infiltration were improved to some extent.The hardness of graphene modified CuW80 contacts prepared by activated sintering melting and infiltration technology has been improved obviously.Along with the increase of the content of graphene by activated sintering aluminized preparation of graphene modified CuW80 contactor material hardness,electrical conductivity,bending strength are increased after the first reduce trends,namely when the graphene content is 0.02 wt.%,the basic properties of the graphene modified CuW80 contactor material the most excellent.With the increase of graphene content,the friction coefficient of CuW80 contacts prepared by activated sintering penetration decreases gradually,and the wear amount and wear of CuW80 contacts first decreases and then increases.When graphene content is 0.02 wt.%,through the preparation of graphene modified activated sintering aluminized CuW80 contactor material amount of wear,wear rate and friction coefficient of active CuW80 respectively electric contact material of 53%,55%,76%,significantly improved the mechanical wear resistance of contact materials.Graphene modified CuW80 contact materials arc ablation resistance obtained obvious ascension,along with the increase of the content of graphene ablation mass loss after 35 times higher after lower first,in the graphene content is 0.2 wt.% when get the optimal performance.While graphene content is 0.02 wt.%,through the preparation of graphene modified activated sintering aluminized CuW80 contactor material under the condition of AC4 test ablation mass loss after 20 times,35 times,respectively,active uhv contact material of 44%,63%.Through the preparation of activated sintering aluminized 0.002 wt.% of graphene modified CuW80 contactor material,uniform microstructure,the mechanical and physical properties meet the requirement of national standard,and mechanical wear resistance and electric arc ablation resistance got obvious improvement.