Synthesis of Zn-Zr and Zn-Zr-Mg Alloys from Mixed ZnO-ZrO2 and ZnO-ZrO2-MgO in CaCl2-NaCl Molten Salt at 873 K

Abstract

Zinc alloys are promising for wide uses thanks to their moderate biodegradability, good mechanical properties, and relevant biocompatibility. In this study, Zn-Zr and Zn-Zr-Mg alloys were prepared through the electro-deoxidation of ZnO-ZrO2 and ZnO-ZrO2-MgO mixtures in CaCl2-NaCl molten salt at 873 K. The electrochemical reduction mechanisms of ZnO, ZrO2, ZnO-MgO, and ZrO2-MgO composites were studied by cyclic voltammetry using metal cavity electrodes. The electrolysis parameters, such as the molar ratio of raw oxides and electrolysis time were also investigated. The results revealed promoted the reduction of ZrO2 and MgO through the formation of Zn and Ca-Zn alloys. Meanwhile, high melting point Zr and Zn-Zr alloys were found important in collecting more Zn and Zn-Mg alloys. A complete reduction of ZnO-ZrO2 and ZnO-ZrO2-MgO mixtures was achieved at ZnO contents above 2/3 of the total mass. Also, Zn, Zr, and Mg elements were homogeneously dispersed in the electrolyzed samples. In sum, the proposed method looks promising for the preparation of novel zinc-based alloys.