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Magnesium alloys have narrow available slip result from close-packed hexagonal structure that limit their processing properties. In the recent work, the Mg-2Zn-0.46Y-0.5Nd, as materials for degradable stents, was applied to produce as-extruded micro-tube with an outer diameter of 3.0 mm and a wall thickness of 0.35 mm by hot extrusion with an extrusion ratio of 105:1 at 653 K and rapid cooling. The fine microstructure of the dynamic recrystallization of as-extruded micro-tube could be preserved by rapid cooling such as water-cooled, resulting in more excellent mechanical properties relative to air-cooled micro-tube. The addition of rare earth elements Y and Nd results in continuous dynamic recrystallization dominated the dynamic recrystallization mechanism. During the hot extrusion process, the activation of the non-basal slip system, especially the pyramidal 〈 c + a 〉 slip, could significantly weaken the texture strength, and the as-extruded micro-tube exhibits weak "RE" texture components 〈 01 1 ¯ 1 〉 ∥ ED and 〈 1 ¯ 2 1 ¯ 1 〉 ∥ ED. Hence, the magnesium alloy micro-tube prepared by the rapid cooling has fine microstructure and weak texture, which is favorable for further process and governance. [ABSTRACT FROM AUTHOR]

In this study, Mg-Zn-Y-Nd alloy micro-tubes with an outer diameter of φ2.46 mm and a wall thickness of 0.14 mm were successfully prepared using an improved technique including hot extrusion with water cooling, multi-pass cold drawing and final annealing treatment. The outer diameter error, inner diameter error and wall thickness error of the cold drawn micro-tubes were 0.58%, 0.36% and 3.43%, respectively. After final annealing at 350 °C for 60 min, the micro-tubes showed refined microstructure with an average grain size of 8.6 μm, a weak texture of the rare earth texture or recrystallization texture, and homogeneously distributed fine second phase particles. The annealed micro-tubes exhibited significantly improved mechanical properties with a yield strength of 240.1 ± 6.0 MPa, an ultimate tensile strength of 319.9 ± 6.0 MPa and a breaking elongation of 22.2 ± 1.0%. Meanwhile, the typical characteristic of ductile morphology could be observed for the fractured specimens. In addition, the annealed micro-tubes also had better corrosion resistance and showed a uniform corrosion morphology. • The thin-walled Mg alloy micro-tubes were prepared by an improved method. • The rare earth texture and recrystallization texture were formed in the annealed microtube. • The annealed micro-tubes showed weakened texture. • High strength and large elongation of the annealed micro-tubes were achieved. [ABSTRACT FROM AUTHOR]