title: Study on biodegradation of the second phase Mg17Al12 in Mg-Al-Zn alloys: in vitro experiment and thermodynamic calculation.
abstract: The in vitro biodegradation behavior of Mg17Al12 as a second phase in Mg-Al-Zn alloys was investigated via electrochemical measurement and immersion test. The Hank's solutions with neutral and acidic pH values were adopted as electrolytes to simulate the in vivo environment during normal and inflammatory response process. Furthermore, the local orbital density functional theory approach was employed to study the thermodynamical stability of Mg17Al12 phase. All the results proved the occurrence of pitting corrosion process with crackings for Mg17Al12 phase in Hank's solution, but with a much lower degradation rate compared with both AZ31 alloy and pure magnesium. Furthermore, a preliminary explanation on the biodegradation behaviors of Mg17Al12 phase was proposed.
authors.affiliation: Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China; Institute of Metal Research, Chinese Academy of Science, Shenyang 110016, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Liu
authors.affiliation: Institute of Metal Research, Chinese Academy of Science, Shenyang 110016, China; Department of Biophysics, China Medical University, Shenyang 110001, China.
authors.forename: Huazhe
authors.initials: H
authors.lastname: Yang
authors.affiliation: Institute of Metal Research, Chinese Academy of Science, Shenyang 110016, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Wan
authors.affiliation: Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
authors.forename: Kehong
authors.initials: K
authors.lastname: Wang
authors.affiliation: Institute of Metal Research, Chinese Academy of Science, Shenyang 110016, China. Electronic address: lltan@imr.ac.cn.
authors.forename: Lili
authors.initials: L
authors.lastname: Tan
authors.affiliation: Institute of Metal Research, Chinese Academy of Science, Shenyang 110016, China. Electronic address: kyang@imr.ac.cn.
authors.forename: Ke
authors.initials: K
authors.lastname: Yang
mesh_terms: D020341:Absorbable Implants; D000497:Alloys / Q000737:chemistry; D000535:Aluminum / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D001826:Body Fluids / Q000737:chemistry*; D003198:Computer Simulation; D004735:Energy Transfer; D008274:Magnesium / Q000737:chemistry*; D008422:Materials Testing; D008956:Models, Chemical; D008968:Molecular Conformation; D044367:Phase Transition; D013499:Surface Properties; D013816:Thermodynamics; D015032:Zinc / Q000737:chemistry*
chemical_list: D000497:Alloys; D001672:Biocompatible Materials; D000535:Aluminum; D008274:Magnesium; D015032:Zinc
keywords: Biodegradation; Magnesium alloy; Mg(17)Al(12) phase; Thermodynamical stability