Thermodynamic Analysis of Copper-Beryllium Alloy Production

摘要

The thermodynamics of the Cu-Be-C-O system was studied in wide ranges of temperature and alloy composition, considering the importance of the minimization of Be_2C and BeO formation in Cu-Be alloy production.The equilibrium relation of molten Cu-Be-C-O system was determined by conducting the following experiments: the solubility measurements of beryllium in molten copper under the conditions of Be_2C-C equilibrium at 1,573 approx 1,873 K and under the conditions of BeO-C equilibrium for normalized CO partial pressure #pi#_(CO) = 0.01 and 1 at 1,423 approx 1,873 K. The activity coefficient of beryllium, #gamma#_(Be) in liquid Cu-Be alloys with respect to pure liquid beryllium as the standard state was also determined as a function of temperature T and mole fraction of beryllium X_(Be) at 1,423 approx 1,873 K:1n#gamma#_(Be)={(1582.1 (T/K)~(-1)-1.9154 log (T/K)+7.1103) X 10~4 (+-80)} centre dot (1-X_(Be))~2 +{(1577.8 (T/K)~(-1) +1.9154 log (T/K)-7.1089) X 10~4 (-+80)}Additionally, the activity of beryllium in solid Cu-Be alloys was determined by an EMF method at 973 approx 1,073 K to establish a partial stability diagram of the solid Cu-Be-O system.Based on the results obtained, the operational conditions of the current Cu-Be alloy production process were also examined from a thermodynamic viewpoint. At the same time, several methods for improving the process were proposed.