Fabrication and Properties of Magnesium Alloy Microtubes for Vascular Stent
Magnesium alloys, as a new type of biodegradable medical metal material, have a promising application in the field of vascular stents. However, the poor deformability of Mg alloys due to hexagonal close-packed (hcp) structure makes it difficult to fabricate their thin tube. In this study, the micro-tubes of Mg-4Zn-0.2Mn-0.2Ca alloy, a new type of degradable magnesium alloy, with 3.1~3.6 mm in outer diameter and 0.25~0.4 mm in wall thickness were prepared by hot extrusion-drawing composite process. The microstructure evolution and mechanical properties of the one with 3.6 mm in outer diameter, 0.4 mm in wall thickness show that the crystal slip, twins and recrystallization occur during the plastic deformation of the tubes, and the work hardening is significant. This drawn tube exhibits a tensile strength of 427.3 MPa, yield strength of 383.4 MPa, and elongation of 5.2%. After annealing at 300℃ for 30 min, the microstructure becomes uniform and the elongation increases to 18.0%, which is conducive to the fabrication of vascular stents.
Duke Scholars
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Published In
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Publication Date
Volume
Issue
Start / End Page
Related Subject Headings
- Materials