Microstructure and texture evolution of fine-grained Mg-Zn-Y-Nd alloy micro-tubes for biodegradable vascular stents processed by hot extrusion and rapid cooling

• 作者: Kaikai Guo Mengyao Liu Jianfeng Wang Yufeng Sun Weiqing Li Shijie Zhu Liguo Wang Shaokang Guan
• 来源期刊: 镁合金学报(英文)
• 学科: 地球科学
• 关键词: Magnesium alloy MICRO-TUBE Microstructure Rapid cooling Texture
• 年，卷（期）: 2020,（3）
• 页码范围: 873-882
• 页数: 10页
• 分类号: X70

摘要

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 3.0mm and a wall thickness of 0.35mm by hot extrusion with an extrusion ratio of 105:1 at 653K 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(011^(-)1)||ED and(1^(-)21^(-)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.