Influence of copper concentration on physical property parameters of high-temperature SF₆-Cu arc

The copper vapor resulting from electrode surfaces in switch devices, such as high-voltage circuit breakers, may modify the characteristics of arc plasmas. The corresponding properties of plasmas contaminated by the metallic vapor are therefore needed to be determined before setting up physical models considering the metal erosion. In this paper, the physical property parameters, including the equilibrium compositions, thermodynamic properties, transport coefficients, and combined diffusion coefficients of SF₆-Cu mixtures are calculated at temperatures of 300-30, 000 K and a pressure of 0.6 MPa based on the Gibbs energy minimization and Chapman-Enskog theory. The influences of copper proportion (up to 90%) on such properties are investigated. It is found that a small quantity of copper has no significant influence on the above thermo-physical properties of SF₆-Cu mixtures, while a large quantity of copper, can generally change these properties dramatically when the content is more than 30%.