ABSTRACT
Zinc, with a density of 7.14 g/cm3, is one of the most abundant essential metal elements in the human body, and it is also an essential component of more than 300 various enzymes (Brar et al. 2012). For biological consideration, it is critical for cellular metabolism and supports protein, DNA synthesis, and the sense of taste and smell (Zhang et al. 2010b; Peng et al. 2012). For adults, the recommended dietary allowance of Zn is about 10-15 mg/day, and higher amounts than these values are often regarded as relativity nontoxic, and amounts near 100 mg/day can be tolerated for some time (Vojtech et al. 2011; Kubasek and Vojtech 2013b). It has been reported that the alloying element Zn for Mg alloys can enhance the ductility and deformability (X. B. Zhang et al. 2012e). Furthermore, introducing Zn into Mg alloys can increase the tensile strength and the hardness through a solid solution hardening mechanism and aging strengthen effect (Jiang et al. 2013). The element Zn can also decrease impurities, such as iron and nickel, in Mg alloys, thus enhancing the corrosion resistance properties (E. L. Zhang et al. 2009b; Vojtech et al. 2011; Kubasek and Vojtech 2013b).
