Zone melting under vacuum purification method for high-purity aluminum

In this study, the authors discover the phenomenon of folding during the process of zone melting and purification of aluminum in a protective atmosphere, for the first time, and these surface folds tend to affect the purity and crystal growth of aluminum. Compared with zone melting purification under a protective atmosphere, when zone melting under vacuum is used, interfacial folding is reduced, and accordingly, the aluminum purity is improved and grain size is increased. Results show that when the vacuum is controlled at 0.1Pa, the aluminum samples show perfect purity and large crystal particles.