Abstract：Graphene is widely used as a reinforcing phase to improve the comprehensive properties of metal materials due to its excellent properties. Most of the existing studies discuss the strengthening effect of graphene on the copper-tungsten alloy contact materials from the perspective of the content of a single component. There is still a lack of research on the ablation resistance of copper-tungsten alloy composites under the combined influence of the graphene content and the tungsten content. Moreover, the internal action mechanism of graphene in enhancing the comprehensive properties of alloy materials is not clear. In this paper, a large current generation platform is built to simulate the current interrupted during the actual breaking process of the contact. The ablation characteristics of the contact materials after arc ablation are analyzed, and the phase field method is used to simulate the dendritic growth process during the ablation of the contact materials to explore the strengthening mechanism of graphene on copper-tungsten contacts. Firstly, using the infiltration sintering method with a high-temperature sintered tungsten skeleton, CuW75, CuW80, and CuW85 alloy contact samples doped with 0%, 0.05%, 0.10%, and 0.15% graphene by mass were prepared. Each group of contact materials is subjected to a large current ablation experiment with a peak impact current of 52 kA for 25 times. Then, the optical schlieren method is used to observe the arcing process, and after the ablation experiment, a precision electronic balance is used to weigh the mass of the contact materials, and the mass loss is used to characterize the ablation resistance of the contact materials. Subsequently, an optical microscope and an electron microscope are used to observe the surface of the composite materials after ablation, and EDS energy spectrum analysis is carried out on the surface of the contact before and after ablation to explore the influence of the addition of graphene on the arc erosion characteristics of the copper-tungsten alloy at the microscale. Finally, a model of graphene-modified copper-tungsten alloy is established by the phase field method, and the dendritic growth process of the composite materials during the ablation process is simulated to explore the action mechanism of the addition of graphene and the tungsten content on the ablation resistance of the copper-tungsten alloy. The experimental results show that the copper-tungsten alloy doped with graphene exhibits better ablation resistance. The doping of graphene can reduce the droplet sputtering amount of the contact materials during the arcing process, thereby reducing the mass loss of the copper-tungsten alloy composites. CuW75 and CuW80 perform best when doped with 0.05% graphene, while CuW85 performs best when doped with 0.10% graphene. Under the combined action of the graphene content and the tungsten content, the CuW85 alloy doped with 0.10% mass fraction of graphene has the least mass loss; at the microscale, the modified materials have fewer ablation characteristics on the surface compared with the unmodified materials after arc ablation, and the surface of the ablated materials contains more oxides; in the phase field simulation, both the graphene content and the tungsten content can inhibit the solute diffusion during dendritic growth, thus affecting the dendritic growth process of the alloy materials. In summary, the experimental analysis leads to the following conclusions: (1) Both the graphene and the tungsten content jointly affect the arc ablation resistance of the modified alloy. With the increase of the graphene content, the mass loss of the modified materials shows a trend of first decreasing and then increasing. Among them, the CuW85 alloy doped with 0.10% mass fraction of graphene has the best performance, and its total mass loss is reduced by 19.9% compared with the unmodified materials. (2) The introduction of graphene can reduce the erosion characteristics of the copper-tungsten alloy contacts caused by the arcing impact at the microscale, thereby inhibiting the ablation damage of the contacts. (3) Graphene can enhance the ablation resistance of the modified alloy by hindering the solute diffusion and promoting the uniform and dense dendritic structure. The simulation calculation indicates that the addition of graphene can make the dendrites uniform and dense and reduce the degree of solute segregation on the surface of the ablated materials, thus inhibiting the expansion of surface cracks.
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2026, Vol. 41 
