Microstructural modification of pure Mg for improving mechanical and biocorrosion properties.
In this study, the effect of microstructural modification on mechanical properties and biocorrosion resistance of pure Mg was investigated for tailoring a load-bearing orthopedic biodegradable implant material. This was performed utilizing the friction stir processing (FSP) in 1-3 passes to refine the grain size. Microstructure was examined in an optical microscope and scanning electron microscope with an electron backscatter diffraction unit. X-ray diffraction method was used to identify the texture. Mechanical properties were measured by microhardness and tensile testing. Electrochemical impedance spectroscopy was applied to evaluate corrosion behavior. The results indicate that even applying a single pass of FSP refined the grain size significantly. Increasing the number of FSP passes further refined the structure, increased the mechanical strength and intensified the dominating basal texture. The best combination of mechanical properties and corrosion resistance were achieved after three FSP passes. In this case, the yield strength was about six times higher than that of the as-cast Mg and the corrosion resistance was also improved compared to that in the as-cast condition.
School of Metallurgy and Materials, College of Engineering, University of Tehran, PO Box 1155-4563, Tehran, Iran. Electronic address: ahmadkhany@ut.ac.ir.
D
D
Ahmadkhaniha
Oulu Southern Institute, University of Oulu, Pajatie 5, FI-85500 Nivala, Finland.
A
A
Järvenpää
Oulu Southern Institute, University of Oulu, Pajatie 5, FI-85500 Nivala, Finland.
M
M
Jaskari
School of Metallurgy and Materials, College of Engineering, University of Tehran, PO Box 1155-4563, Tehran, Iran.
M Heydarzadeh
MH
Sohi
School of Metallurgy and Materials, College of Engineering, University of Tehran, PO Box 1155-4563, Tehran, Iran.
A
A
Zarei-Hanzaki
Department of Industrial Engineering, University of Trento, via Sommarive n. 9, 38123 Trento, Italy.
M
M
Fedel
Department of Industrial Engineering, University of Trento, via Sommarive n. 9, 38123 Trento, Italy.
F
F
Deflorian
Centre for Advanced Steels Research, University of Oulu, PO Box 4200, 90014 Oulu, Finland.
L P
LP
Karjalainen
D000497:Alloys; D001672:Biocompatible Materials; D003343:Corrosion; D008274:Magnesium / Q000737:chemistry*; D008422:Materials Testing; D055595:Mechanical Phenomena; D014961:X-Ray Diffraction
D000497:Alloys; D001672:Biocompatible Materials; D008274:Magnesium
Biocorrosion; Friction stir processing; Grain size; Mechanical properties; Pure Mg; Texture