Influence of Calcium on the Structure and Mechanical Properties of Biodegradable Zinc Alloys

Abstract

In this work, Zn-1.5Mg-0.5Ca alloy was studied. The alloy composition was chosen according to the results of our previous work that was focused on the research of biodegradable materials. The mechanical properties of such cast alloy are similar to the characteristics of human bones. Moreover, Zn-1.5Mg alloy itself satisfies biocompatibility requirements. The main goal of this work was to improve the mechanical properties of this alloy. A small addition of calcium affected both the alloy microstructure and mechanical properties. Light microscope and scanning electron microscope were used for the analysis of microstructure. After calcium addition, secondary phases were visible in observed micrographs; their composition was verified by XRD. Mechanical properties (Vickers hardness, compressive and tensile tests) were studied and compared with the Zn-1.5Mg alloy prepared in our previous work. Based on presented results, Zn-1.5Mg-0.5Ca alloy is intended for use in medicine as a suitable material for temporary implants.

The Prospects of Zinc as a Structural Material for Biodegradable Implants—A Review Paper

“…In other cases, a chronic inflammatory response against the implant may undermine the therapeutic function of the device. In such circumstances, a second operation may be necessary to extract the implant, resulting in additional injury and expense [1,3,6,7].…”

Biodegradable ZnLiCa ternary alloys for critical-sized bone defect regeneration at load-bearing sites: In vitro and in vivo studies

“…However, the mechanical properties of pure Zn is unsatisfactory [ 18 , 19 ]. To enhance the performance of Zn-based biodegradable metals, alloying elements, including Li [ 20 , 21 ], Mg [ [22] , [23] , [24] , [25] , [26] , [27] , [28] ], Ca [ 29 , 30 ], Sr [ 12 , 31 ], Cu [ [32] , [33] , [34] , [35] ], Ag [ [36] , [37] , [38] ], Mn [ [39] , [40] , [41] , [42] ] and Fe [ 43 , 44 ], were introduced into the system. Among these researches, element Li have brought the most significant improvement in mechanical strength [ 45 ].…”

“…Also, Ca is an important component of many biomaterials, such as hydroxyapatite (HA) [ 52 , 53 ], tricalcium phosphate (TCP) [ 54 , 55 ], and silicates [ 56 , 57 ]. Moreover, Ca has been widely used as an alloying element in biodegradable metals, such as Mg-Ca [ 58 , 59 ], Zn-Ca [ 29 , 30 ], Mg-Zn-Ca [ [60] , [61] , [62] ], etc. Previous studies have shown that Ca could bring improvements in the biocompatibility and mechanical properties of the biodegradable metals.…”