Design strategy for new biodegradable Mg–Y–Zn alloys for medical applications

Abstract

Design strategy for new biodegradable Mg-Y-Zn alloys for medical applications Dedicated to Professor Dr. Franz Jeglitsch on the occasion of his 75 th birthdayThe aim of this article is to describe the design strategy deployed in developing new biodegradable Mg-Y-Zn alloys. The development approach is based on a microalloying concept which aims to restrict grain growth considerably during alloy casting and forming. We discuss the efficiency of the design approach, and evaluate the characteristics of the new alloys using metal-physical experiments, thermodynamic calculations and transmission electron microscopy analysis. Our results show that after extrusion the alloys have very fine grains (< 10 lm), exhibit high ductility (uniform elongation: 17 -20 %) at considerable strength (ultimate tensile strength: 250 -270 MPa) and reveal the presence of finely distributed intermetallic particles which are stable upon annealing. Due to an attractive combination of mechanical, electrochemical and biological properties, the new alloys are very promising not only for applications in medicine but also in other fields.A. C. Hänzi et al.: Design strategy for new biodegradable Mg -Y -Zn alloys for medical applications Int.

On the in vitro and in vivo degradation performance and biological response of new biodegradable Mg–Y–Zn alloys☆

“…New Mg alloys were recently developed with the aim of fulfilling the above requirements [9,10]. Extruded Mg alloys often reveal relatively low room-temperature ductility because of the materials' insufficient number of independent deformation modes [11].…”

“…Since the second phases in the Mg-Y-Zn alloys developed are also very stable [10], their growth-inhibiting potential can be deployed even at elevated temperatures. This allows the application of various forming procedures and heat treatments.…”

“…The localized corrosion as observed in the ''first generation" Mg-Zn alloys is not tolerable in stent devices [16]. Taking into account the favorable mechanical but insufficient electrochemical properties of these alloys, a new family of Mg-Y-Zn alloys has been developed with the aim of achieving the mechanical, electrochemical and biological characteristics suitable for medical applications [10]. These Mg-Y-Zn alloys (denoted as ZW21 and WZ21) are assumed to meet the degradation demands [16].…”

“…These Mg-Y-Zn alloys (denoted as ZW21 and WZ21) are assumed to meet the degradation demands [16]. In addition, these alloys also exhibit high ductility (uniform elongation of 17-20%) and appropriate strength (ultimate tensile strength: 250-270 MPa) [10]. The high ductility is ascribed both to the fine-grained microstructure (enabling complementary deformation modes) and to the weak texture of the Mg-Y-Zn alloys [17].…”

Mg and Its Alloys for Biomedical Applications: Exploring Corrosion and Its Interplay with Mechanical Failure

“…Its low density and elastic modulus best mimic the properties of (Table 2). Moreover, Mg is the fourth most abundant element in the human body (it is recommended that an adult receives 240-420 mg daily) and it is essential for the metabolism in many biological mechanisms (Mg is a cofactor for many enzymes [46]). Finally, Mg 2+ ions, resulting from the degradation process (see Section 2), are reported to aid the healing and growth of tissue.…”