title: Development and evaluation of a magnesium-zinc-strontium alloy for biomedical applications--alloy processing, microstructure, mechanical properties, and biodegradation.
abstract: A new biodegradable magnesium-zinc-strontium (Mg-Zn-Sr) alloy was developed and studied for medical implant applications. This first study investigated the alloy processing (casting, rolling, and heat treatment), microstructures, mechanical properties, and degradation properties in simulated body fluid (SBF). Aging treatment of the ZSr41 alloy at 175 °C for 8h improved the mechanical properties when compared to those of the as-cast alloy. Specifically, the aged ZSr41 alloy had an ultimate tensile strength of 270 MPa, Vickers hardness of 71.5 HV, and elongation at failure of 12.8%. The mechanical properties of the ZSr41 alloy were superior as compared with those of pure magnesium and met the requirements for load-bearing medical implants. Furthermore, the immersion of the ZSr41 alloy in SBF showed a degradation mode that progressed cyclically, alternating between pitting and localized corrosion. The steady-state average degradation rate of the aged ZSr41 alloy in SBF was 0.96 g/(m(2)·hr), while the pH of SBF immersion solution increased. The corrosion current density of the ZSr41 alloy in SBF solution was 0.41 mA/mm(2), which was much lower than 1.67 mA/mm(2) for pure Mg under the same conditions. In summary, compared to pure Mg, the mechanical properties of the new ZSr41 alloy improved while the degradation rate decreased due to the addition of Zn and Sr alloying elements and specific processing conditions. The superior mechanical properties and corrosion resistance of the new ZSr41 alloy make it a promising alloy for next-generation implant applications.
authors.affiliation: School of Materials and Metallurgy, Northeastern University, Shenyang 110004, China.
authors.forename: Ren-guo
authors.initials: RG
authors.lastname: Guan
authors.forename: Aaron F
authors.initials: AF
authors.lastname: Cipriano
authors.forename: Zhan-yong
authors.initials: ZY
authors.lastname: Zhao
authors.forename: Jaclyn
authors.initials: J
authors.lastname: Lock
authors.forename: Di
authors.initials: D
authors.lastname: Tie
authors.forename: Tong
authors.initials: T
authors.lastname: Zhao
authors.forename: Tong
authors.initials: T
authors.lastname: Cui
authors.forename: Huinan
authors.initials: H
authors.lastname: Liu
mesh_terms: D000497:Alloys / Q000737:chemistry* / Q000494:pharmacology; D001673:Biodegradation, Environmental; D020811:Biomedical Technology; D001826:Body Fluids / Q000187:drug effects; D003343:Corrosion; D006244:Hardness / Q000187:drug effects; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D008422:Materials Testing; D055595:Mechanical Phenomena / Q000187:drug effects; D008855:Microscopy, Electron, Scanning; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties; D013718:Tensile Strength / Q000187:drug effects; D014961:X-Ray Diffraction
chemical_list: D000497:Alloys
keywords: Degradation in simulated body fluid; Magnesium alloy; Magnesium–zinc–strontium alloy; Mechanical property; Medical implants; Mg–Zn–Sr alloy microstructure