title: Flow-induced corrosion behavior of absorbable magnesium-based stents.
abstract: The aim of this work was to study corrosion behavior of magnesium (Mg) alloys (MgZnCa plates and AZ31 stents) under varied fluid flow conditions representative of the vascular environment. Experiments revealed that fluid hydrodynamics, fluid flow velocity and shear stress play essential roles in the corrosion behavior of absorbable magnesium-based stent devices. Flow-induced shear stress (FISS) accelerates the overall corrosion (including localized, uniform, pitting and erosion corrosions) due to the increased mass transfer and mechanical force. FISS increased the average uniform corrosion rate, the localized corrosion coverage ratios and depths and the removal rate of corrosion products inside the corrosion pits. For MgZnCa plates, an increase of FISS results in an increased pitting factor but saturates at an FISS of ∼0.15Pa. For AZ31 stents, the volume loss ratio (31%) at 0.056Pa was nearly twice that (17%) at 0Pa before and after corrosion. Flow direction has a significant impact on corrosion behavior as more severe pitting and erosion corrosion was observed on the back ends of the MgZnCa plates, and the corrosion product layer facing the flow direction peeled off from the AZ31 stent struts. This study demonstrates that flow-induced corrosion needs be understood so that Mg-based stents in vascular environments can be effectively designed.
authors.affiliation: National Science Foundation Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A & T State University, Greensboro, NC 27411, USA; Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Wang
authors.affiliation: National Science Foundation Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A & T State University, Greensboro, NC 27411, USA.
authors.forename: Venkataraman
authors.initials: V
authors.lastname: Giridharan
authors.affiliation: College of Engineering, University of Cincinnati, Cincinnati, OH 45221-0172, USA.
authors.forename: Vesselin
authors.initials: V
authors.lastname: Shanov
authors.affiliation: National Science Foundation Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A & T State University, Greensboro, NC 27411, USA.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Xu
authors.affiliation: National Science Foundation Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A & T State University, Greensboro, NC 27411, USA.
authors.forename: Boyce
authors.initials: B
authors.lastname: Collins
authors.affiliation: National Science Foundation Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A & T State University, Greensboro, NC 27411, USA.
authors.forename: Leon
authors.initials: L
authors.lastname: White
authors.affiliation: National Science Foundation Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A & T State University, Greensboro, NC 27411, USA.
authors.forename: Yongseok
authors.initials: Y
authors.lastname: Jang
authors.affiliation: National Science Foundation Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A & T State University, Greensboro, NC 27411, USA.
authors.forename: Jagannathan
authors.initials: J
authors.lastname: Sankar
authors.affiliation: Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China. Electronic address: nhuang@263.net.
authors.forename: Nan
authors.initials: N
authors.lastname: Huang
authors.affiliation: National Science Foundation Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A & T State University, Greensboro, NC 27411, USA. Electronic address: yyun@ncat.edu.
authors.forename: Yeoheung
authors.initials: Y
authors.lastname: Yun
mesh_terms: D020341:Absorbable Implants; D000497:Alloys / Q000737:chemistry*; D001783:Blood Flow Velocity; D001807:Blood Vessel Prosthesis; D003343:Corrosion; D019544:Equipment Failure Analysis; D008274:Magnesium / Q000737:chemistry*; D008422:Materials Testing; D011474:Prosthesis Design; D012212:Rheology / Q000379:methods*; D015607:Stents; D013499:Surface Properties
chemical_list: D000497:Alloys; C586533:Mg-Al-Zn-Mn-Si-Cu alloy; D008274:Magnesium
keywords: Corrosion; Corrosion products; Flow-induced shear stress; Magnesium; Stent