Kinetics of indium and indium-tin soldering materials in vacuum volatilization

Vacuum volatilization is a clean and efficient method for metal purification, alloy separation, and comprehensive recovery of secondary resources. The evaporation kinetics of In and In-Sn alloys were investigated to better understand the evaporation mechanism during the vacuum volatilization of In. The evaporation rates of the In and In-Sn alloys at 1173-1373 K and 5 Pa increased significantly with increasing temperature in accordance with the equation omega = e(a+b center dot T). The evaporation rates at 1323 K and 5 Pa decreased with increasing crucible depth in accordance with the equation omega = a2+(a1-a2)/(1+e(h-b)/c). For In and In-Sn, the total mass-transfer coefficients of In were obtained at different temperatures and crucible depths. A theoretical kinetic model of In was established and limiting links were obtained vacuum volatilization of In and In-Sn.