title: Stress corrosion cracking and corrosion fatigue characterisation of MgZn1Ca0.3 (ZX10) in a simulated physiological environment.
abstract: Magnesium (Mg) alloys have attracted great attention as potential materials for biodegradable implants. It is essential that an implant material possesses adequate resistance to cracking/fracture under the simultaneous actions of corrosion and mechanical stresses, i.e., stress corrosion cracking (SCC) and/or corrosion fatigue (CF). This study investigates the deformation behaviour of a newly developed high-strength low-alloy Mg alloy, MgZn1Ca0.3 (ZX10), processed at two different extrusion temperatures of 325 and 400°C (named E325 and E400, respectively), under slow strain tensile and cyclic tension-compression loadings in air and modified simulated body fluid (m-SBF). Extrusion resulted in a bimodal grain size distribution with recrystallised grain sizes of 1.2 μm ± 0.8 μm and 7 ± 5 μm for E325 and E400, respectively. E325 possessed superior tensile and fatigue properties to E400 when tested in air. This is mainly attributed to a grain-boundary strengthening mechanism. However, both E325 and E400 were found to be susceptible to SCC at a strain rate of 3.1×10-7s-1in m-SBF. Moreover, both E325 and E400 showed similar fatigue strength when tested in m-SBF. This is explained on the basis of crack initiation from localised corrosion following tests in m-SBF.
authors.affiliation: Department of Mechanical & Aerospace Engineering, Monash University (Melbourne), VIC 3800, Australia. Electronic address: jafarisajjad1@gmail.com.
authors.forename: Sajjad
authors.initials: S
authors.lastname: Jafari
authors.affiliation: Department of Mechanical & Aerospace Engineering, Monash University (Melbourne), VIC 3800, Australia; Department of Chemical Engineering, Monash University (Melbourne), VIC 3800, Australia.
authors.forename: R K Singh
authors.initials: RKS
authors.lastname: Raman
authors.affiliation: Department of Mechanical & Aerospace Engineering, Monash University (Melbourne), VIC 3800, Australia.
authors.forename: Chris H J
authors.initials: CHJ
authors.lastname: Davies
authors.affiliation: Laboratory of Metal Physics and Technology, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Joelle
authors.initials: J
authors.lastname: Hofstetter
authors.affiliation: Laboratory of Metal Physics and Technology, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Uggowitzer
authors.affiliation: Laboratory of Metal Physics and Technology, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Jörg F
authors.initials: JF
authors.lastname: Löffler
mesh_terms: D020341:Absorbable Implants; D000497:Alloys / Q000032:analysis*; D003343:Corrosion; D008274:Magnesium / Q000032:analysis*; D008422:Materials Testing; D013718:Tensile Strength
chemical_list: D000497:Alloys; D008274:Magnesium
keywords: Biodegradable implants; Corrosion fatigue; Magnesium alloys; Stress corrosion cracking; Twinning