## 3 **Introduction**
Furthermore, biologically, Si is known to be a trace element that plays a critical role in several physiological processes, particularly in the growth and maintenance of bone tissue [17; 18; 19; 20; 21]. Despite these benefits, the brittle nature of the Mg\({}_{2}\)Si phase within the alloy can decrease ductility, and the formation of larger particles can increase stress concentration points and crack initiation sites [15; 16]. One strategy to enhance the mechanical properties of Mg alloys with Si additions is the insertion of a third element, with zinc (Zn) being a notable option [22]. Biologically, Zn plays a crucial role in connective tissue metabolism, bone mineralization, and collagen structure development [23; 24], and is involved in over 300 enzymatic reactions [7; 25], making it a suitable element for consideration in the development of biocompatible alloys. From a performance standpoint, Zn addition also has several mechanical and corrosion-related benefits. [PERSON] et al. [26] conducted a study on Mg-0.6 wt. Si-x wt.% Zn alloys (where x = 0, 0.5, 1.3, 1.5, and 1.6) and they observed that the addition of 0.5 wt.% Zn was sufficient to modify the morphology of the Mg\({}_{2}\)Si phase. This modification led to a more refined Mg\({}_{2}\)Si particle distribution. When the Zn content was increased to values greater than or equal to 1.5 wt.%, it resulted in the morphological transformation of the eutectic Mg\({}_{2}\)Si into a Chinese Script-like structure, and the formation of a small amount of MgZn in the Mg matrix [26]. Zn tends to enhance the mechanical strength of the Mg matrix through solid solution and precipitation mechanisms, as well as through the refinement of Mg\({}_{2}\)Si [25]. [PERSON] et al. [26] reported an improvement in the tensile properties of the alloy with Zn content up to 1.5 wt.%. Furthermore, [PERSON], et al. [27] also investigated Mg-x wt.% Zn alloys (where x = 1, 2, 3, 4, 5, and 6) that were cast and solidified, and observed improvements in mechanical properties, such as tensile strength, yield strength, and ductility, with increasing Zn content up to 4 wt.%. Beyond 4 wt.% of Zn, the occurrence of MgZn precipitates was noted in the microstructure. With the increase in Zn above 4 wt.%, the morphology of the phase changed to a coarse structure along the grain boundaries. Another study by [PERSON] et al. [28] found that the presence of 1.5 wt.% Zn led to improved corrosion resistance of the alloy. This improvement was attributed to the increased corrosion resistance of the Mg matrix when in solution with Zn, and to the refinement of the Mg\({}_{2}\)Si phase. This refinement helped mitigate the impact of localized corrosion at the interface between the Mg matrix and the Mg\({}_{2}\)Si phase. Although the addition of Zn generally improves corrosion resistance compared to pure Mg [25], [PERSON] et al. [29] noted a deterioration in corrosion resistance due to the interconnected MgZn phase at higher Zn wt.% (\(\sim\)5%). This interconnected MgZn phase acts as a cathode, accelerating localized galvanic corrosion and reducing overall corrosion resistance due to the distinct electrochemical properties of the Mg matrix and MgZn phase [27]. Therefore, based on considerations of mechanical properties and corrosion resistance, a review of the literature suggests that the Zn content in Mg-Zn alloys should not exceed an optimal compositional range of around 2 to 3 wt.%. The potential applications of absorbable alloys in the Mg-Si-Zn system will be strongly affected by the microstructural characteristics of the alloys. 2D microstructural characterization using traditional microscopy-based techniques is often inadequate in capturing the complex shapes of the intermetallic phases within the Mg-Si-Zn family of alloys.