Kinetics of Al Evaporation from Liquid U-Al Alloys in Vacuum Induction Melting

A research on kinetics of Al evaporation from liquid U-Al alloys was made in a vacuum induction melting (VIM) furnace at 1673-1843 K. The evaporation rate of Al was found to be first order with respect to Al content in the melt. The overall mass transfer coefficient of Al was determined and it was found that the evaporation rate of Al increased with increasing temperatures. The apparent activation energy of Al evaporation at 1673-1843 K was 171.5 kJ mol−1. The value of mass transfer coefficient of Al in the liquid phase was estimated to be 3.77 × 10−6, 7.41 × 10−6, and 9.40 × 10−6 m s−1 at 1673, 1753, and 1843 K, respectively. Meanwhile, rate determining steps were discussed and it was concluded that the evaporation rate of Al is mainly controlled by liquid phase mass transfer.