KF-AlF_3系溶剂组成对KBF_4与Al熔体界面反应的影响

INFLUENCES OF KF-AIF_3 SOLVENT COMPOSITIONS ON THE INTERFACIAL REACTIONS BETWEEN ALUMINUM AND KBF_4

研究了不同组成的KF-AlF3系溶剂对KBF_4与Al熔体界面反应的影响.结果表明,采用不同组成的KF-AlF_3系溶剂时,在氟化盐/Al界面处均有铝硼化合物层形成;当采用共晶成分或过共晶成分KF-AlF_3溶剂时,铝硼化合物层与Al之间存在的AlF_3可使铝硼化合物层与Al局部或完全脱离;当采用亚共晶成分KF-AlF_3溶剂时,在氟化盐/Al界面处未观察到AlF_3存在.对不同组成KF-AlF_3系溶剂和KBF_4的反应过程进行了研究,分析了氟化盐/Al界面处AlF_3的形成机理。

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 A1 and KBF_4 play a critical role in the production of Al-B master alloys.Investigations on the interfacial reactions in four different KF-AlF_3 solvents were carried out.It was demonstrated that a boride layer formed at the interface for all the four solvents.There existed AlF_3 between the boride layer and the aluminum melt when the eutectic KF-AlF_3 solvent or the hypereutectic solvents were used.AlF_3 formed by the reaction between BF_3 and A1.