Study on Evaporation Kinetic Nb-7Ta Alloy in the EBM Vacuum Melting

The Evaporation kinetic characteristic of Nb-7Ta alloy in the EBM process were studied in this paper.The results show that the evaporation reaction of Nb and Fe was in the form of single atoms.The diffusion constant of Nb in the liquid Nb-7Ta alloy is 5.78 × 10^-7m / s; the reaction constant of Nb in the evaporation reaction is 1.29 × 10^-5m / s; the diffusion coefficient of Fe in liquid Nb-7Ta alloy is 8.10 × 10^-7m / s,the reaction coefficient of Fe in the evaporation reaction is 1.55 ×10^-5m / s.The evaporating process of matrix Nb as well as impurity Fe from the Nb-7Ta alloy liquid were both controlled by diffusion.