| As the economy continues to develop at a high speed,the amount of electricity used continues to increase,which makes the high-voltage circuit breakers develop toward ultra-high voltage and large capacity,and requires high-voltage circuit breakers to operate frequently to meet reactive power regulation.This requires the core components of the circuit breaker to be electrically The contact material has excellent wear resistance,electrical conductivity,fusion resistance,arc erosion resistance,etc.The coppertungsten composite material is widely used in high voltage circuit breakers due to its excellent wear resistance and ablation resistance,but The active copper-tungsten composites can no longer meet the maintenance-free requirements throughout the life cycle of the actual project.The main reason is that the mechanical contact between the electrical contacts and the arc generated during the disconnection during the opening and closing of the circuit breaker Ablation of the electrical contacts.Therefore,improving the mechanical wear resistance and arc erosion resistance of the electrical contact composite material is an urgent problem to be solved.In this context,the performance of copper-tungsten composite(CuW80 is optimized,and its wear resistance and arc ablation resistance are improved while maintaining other properties such as conductivity.Graphene exhibits excellent self-lubricity due to its excellent mechanical,thermal and electrical properties,as well as its special lamellar structure,making it a popular reinforcement material that enhances the wear resistance and thermal conductivity of composites.These studies provide us with ideas: using the excellent properties of graphene,lead into copper-tungsten composites,improve the wear resistance and arc ablation resistance of copper-tungsten composites.However,there is a strong van der Waals force between graphene,which makes graphene easy to agglomerate when it is together with copper powder,and it is difficult to achieve uniform dispersion.The existing method of ball milling and molecular level mixing has been improved to some extent.The dispersion of graphene,but it causes damage to graphene,which limits the excellent properties of graphene.In order to solve this problem,the copper powder was dispersed by using the spacer,and high-quality graphene was grown in situ on the surface of the copper powder by CVD.The high-quality graphene was coated on the surface of the copper powder,which solved the difficulty of uniform dispersion of graphene.Poor quality.After graphene was grown,copper-tungsten composites were prepared by high temperature liquid phase sintering using CuW80 standard.The test results showed that the addition of graphene was the same as that of CuW80 without graphene,but the composite was obviously improved.Friction and wear properties of the material.In terms of electrical conductivity,the conductivity of CuW80 is 42.15 % IACS,and the conductivity of Gr/CuW80 is 42.27 % IACS,which meets the requirements of national standards.In terms of wear resistance,the friction coefficient of CuW80 is about 0.9,the friction coefficient of Gr/CuW80 is about 0.75,the friction coefficient is reduced by 0.15,which is reduced by 16.7 %,and the wear rate of CuW80 and Gr/CuW80 in terms of wear resistance.The ratio is 3.53(10-6mm3/(N?m)) and 2.66(10-6mm3/(N?m)),respectively,which is a decrease of 24.6 %.Compared with the commercial application of CuW80,the wear rate is still reduced by 26.9 %.It indicates that the addition of graphene significantly improves the wear resistance of the composite.In terms of arc erosion resistance,the loss mass of Gr/CuW80 is 3.41 mg,the loss mass of CuW80 is 5.55 mg,and the loss mass is reduced by 2.14 mg,indicating that graphene is added in CuW80,which improves the wear resistance of the composite.With the commercial application of CuW80,the loss quality was also reduced by 1.79 mg. |
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