Nd,Zn微量元素在Mg-Zn-Y-Nd血管合金支架中组织学特性和改性的变化  

Microstructure and modification of Nd and Zn trace elements in a Mg-Zn-Y-Nd vascular alloy stent

作　　者：鲁雪丽[1] 姚新亮[1] 李彦明[1] 

机构地区：[1]河南大学淮河医院,河南省开封市475000

出　　处：《中国组织工程研究》2017年第10期1571-1576,共6页Chinese Journal of Tissue Engineering Research

基　　金：河南省科技攻关项目(2013HN01106)~~

摘　　要：背景:随着材料学的不断发展,镁合金血管支架材料在心血管疾病中广泛运用,但是传统合金材料难以满足血管支架要求,因此采取有效措施完成支架表面改性,提高血管支架的组织、力学性能具有深远的意义。目的:观察血管支架在快速凝固Mg-Zn-Y-Nd合金中的组织学及表面改性情况。方法:选择具备良好力学性能、耐腐蚀性能的低锌系Mg-2Zn-0.2Y合金为基本材料,向材料中加入Nd,Zn元素完成合金支架的细化;经过对支架的挤压细化组织性能完成支架表面改性,提高合金材料的综合性能,获得血管支架用新型镁合金并完成支架表面改性。通过金相显微组织、扫描电镜能谱及射线衍射分析实验了解制备支架的组织性能;通过硬度、拉伸实验了解支架的力学性能。结果与结论:(1)金相显微镜组织观察结果显示:当不加入Y时,镁合金支架第2相为杆状,存在少许颗粒嵌入在基体中;当向镁合金支架中混入0.5%Y元素时,支架第2相中杆状物明显减少,以颗粒状为主,且均匀分布在机体中;加入1.0%的Y时,第2相数增加,晶粒中可见大量枝晶,第2相存在不连续杆状物;加入1.5%的Y时,合金组织中的大枝晶与局枝晶混合,第2相为杆状。(2)射线衍射分析实验结果表面:Mn-Zn-0.5Nd合金与Mn-Zn-1.0Nd合金中均含有相同的相(Mg4Zn7和(Nd,Y)2Zn17相)。当Nd浓度提高为1%时,合金中出现新的MgZ n2相;(3)镁合金改性材料SEM及EDS实验结果显示:镁合金改性后第2相中含有Zn元素、Nd及Y元素,并且Nd元素、Y元素含量和与Zn含量较接近。EDS分析可知:加入Zr元素后层片状第2相中Zn元素水平明显下降,Y元素、Nd元素含量提高,能获得更加稳定的性能;(4)显微硬度实验结果显示:随着镁合金含量的不断增加,合金显微硬度值不断增加;(5)拉伸实验结果显示:Mg-Zn-Y-0.5Nd-Zr支架的抗拉强度、屈服强度,显著高于Mg-Zn-Y-0.5Nd,Mg-Zn-Y-1.0Nd,Mg-Zn-Y-1.0Nd-Zr(P<0.05);BACKGROUND： With the continuous development of materials science, magnesium alloy vascular stent materials have become a hot research. Because of the mechanical properties and biocompatibility of commercial magnesium alloy, it is difficult to meet the requirements of vascular stents. Therefore, effective measures to improve the sten＆#39;s surface properties and comprehensive performance become the focus of research.OBJECTIVE： To study the histology and surface modification of vascular stents in rapidly solidified Mg-Zn-Y-Nd alloy.Methods： The low-zinc Mg-2Zn-0.2Y alloy with good mechanical properties and corrosion resistance was selected as the basic material, and Nd and Zn elements were added to refine the alloy stents. After the microstructure of the stent was extruded, the surface modification of the stent was completed and the comprehensive properties of the alloy were improved. The new magnesium alloy for the stent was obtained and the stent surface was modified. The metallographic microstructure, scanning electron microscopy and radiological analysis were used to study the microstructure and mechanical properties of the prepared stents. The mechanical properties of the stents were investigated by hardness and tensile tests.RESULTS AND CONCLUSION： （1） Metallographic microstructure results showed that： when Y elements were not added, the second phase of the magnesium alloy was rod-shaped, and there were a few granules embedded in the matrix. After addition of 0.5% Y elements, in the second phase of the magnesium alloy stent, the shafts were significantly reduced in number, and granules were increased in number and evenly distributed in the body. After the addition of 1% Y,the second phase number increased, a large number of dendrites were visible in the grains, and discontinuous rods existed in the second phase. After the addition of 1.5% Y, the second phase was rod-shaped, with mixture of large and local dendrites in the alloy. （2） X-ray diffraction test results： Mn-Zn-0.5Nd alloy and M

关 键 词：生物材料 材料相容性 材料学及表面改性 血管支架 快速凝固 Mg-Zn-Y-Nd合金 组织分布 表面改性 挤压工艺 电化学测试 拉伸实验 组织性能 力学性能 

分 类 号：R318[医药卫生—生物医学工程]