INFLUENCES OF KF-AlF3 SOLVENT COMPOSITIONS ON THE INTERFACIAL REACTIONS BETWEEN ALUMINUM AND KBF4

Al-B alloys are widely used in industries. Their manufacturing has attracted great attentions. Generally, the Al-B master alloys are manufactured by reacting KBF4 with molten aluminum. A lot of work has been done to investigate the effects of reaction technologies on the manufacturing of Al-B alloys. But little attentions were paid to the reaction mechanisms at the interface between the aluminum melt and the fluoride salt. The interfacial reactions between Al and KBF4 play a critical role in the production of Al-B master alloys. Investigations on the interfacial reactions in four different KF-AlF3 solvents were carried out. It was demonstrated that a boride layer formed at the interface for all the four solvents. There existed AlF3 between the boride layer and the aluminum melt when the eutectic KF-AlF3 solvent or the hypereutectic solvents were used. AlF3 formed by the reaction between BF3 and Al.