TITLE:
Effect of Adding Sb on Microstructure, Mechanical Properties and in Vitro Degradation Behavior of as Cast Mg-4wt% Zn Alloy for Medical Application
AUTHORS:
Hadeer I. Mohamed, Mohamed E. Moussa, Mohamed A. Waly, Gamilla S. Al-Ganainy, Aya B. Ahmed, Mona S. Talaat
KEYWORDS:
Mg Alloy, Mechanical Properties, Autocatalytic Route, Degradation Rate, Calcium Phosphate Coating
JOURNAL NAME:
Journal of Surface Engineered Materials and Advanced Technology,
Vol.7 No.4,
October
26,
2017
ABSTRACT: Magnesium (Mg) and its alloys are one of a novel kind of biodegradable metallic implants which attracted much fundamental research to develop its clinical application. Nevertheless, it has more restrictions in biomedical applications because it degrades too fast at the early stage after implantation, thus commonly leading to some problems such as early fast mechanical loss, hydric bubble aggregation, gap formation between the implants and the tissue. This work aims to study the effect of 0.5 wt% Sb addition on the microstructure, mechanical properties and degradation behavior of as cast Mg-4wt% Zn alloy. The evaluation process was conducted using optical and scanning electron microscopy, X-ray diffraction, tensile and compression tests, in addition to a corrosion study by immersing in simulated body fluid (SBF). Results showed that Sb refines the grain size of the base alloy and also enhances its mechanical properties and degradation rate as well. These were due to the formation of the secondary phase of Mg3Sb2. To get better degradation rate, the Mg-4wt% Zn and Mg-4wt% Zn-0.5wt% Sb alloys are coated with Ca-P using autocatalytic technique. The results demonstrated that the formed coat layer improves the degradation rate of samples under the condition of this study. The current study shows that Mg-4wt% Zn-0.5wt% Sb alloy has good mechanical properties and when it coated by Ca-P, it gave a better corrosion resistance that makes it ideal for biodegradable medical application.