Calculation of diffusion coefficients in airmetal thermal plasmas

Yann Cressault (1) , A Gleizes (2)

1 LAPLACE-MPP - Matériaux et Procédés Plasmas
2 LAPLACE - LAboratoire PLasma et Conversion d'Energie

This paper presents the combined diffusion coefficients of metal vapours (silver, copper and iron) in air thermal plasmas for temperatures ranging from 300 to 30000K. The theory used to calculate these coefficients is remembered and validated by comparison with literature values in several cases such as Ar-He, Ar-Cu and N 2 -O 2 mixtures. The results are discussed showing the influences of the metal concentration, of the vapour nature and of the pressure. The results show rather similar behaviour for the three metals. The maximum values of the combined ordinary diffusion coefficient in the evolution with temperature, is obtained for temperature around 10 000K but this peak is shifted to the highest temperatures when the metal proportion increases. Another result shows that the diffusion coefficient decreases when pressure increases.

Mots clés: diffusion; thermal plasmas properties; air; copper; silver; iron

Domaines: Plasmas

Yann Cressault, A Gleizes. Calculation of diffusion coefficients in airmetal thermal plasmas. Journal of Physics D: Applied Physics, 2010, 43 (43), pp.434006. ⟨10.1088/0022-3727/43/43/434006⟩. ⟨hal-00569736⟩