The processing of ultrafine-grained Mg tubes for biodegradable stents

被引：88

作者：

Ge, Qiang ^{[1
]}

Dellasega, David ^{[2
]}

Demir, Ali Goekhan ^{[1
]}

Vedani, Maurizio ^{[1
]}

机构：

[1] Politecn Milan, Dept Mech Engn, I-20156 Milan, Italy

[2] Politecn Milan, Dept Energy, I-20156 Milan, Italy

来源：

ACTA BIOMATERIALIA | 2013年 / 9卷 / 10期

关键词：

Biodegradable stent; ECAP; Ultrafine grains; Mg alloy; Extrusion; MAGNESIUM ALLOY; MECHANICAL-PROPERTIES; MICROSTRUCTURE; EXTRUSION;

D O I：

10.1016/j.actbio.2013.01.010

中图分类号：

R318 [生物医学工程];

学科分类号：

0831 ;

摘要：

An investigation was carried out on equal-channel angular pressing (ECAP) and extrusion processing of a ZM21 Mg alloy to obtain an improved candidate material for the manufacturing of biodegradable Mg stents. Ultrafine-grain size billets of the ZM21 alloy were obtained by two-stage ECAP aimed at achieving an initial refining of the structure at 200 degrees C and then reaching the submicrometer grain size range by lowering the processing temperature down to 150 degrees C. The investigation revealed a significant improvement in the properties of the ECAP-treated samples compared with the starting coarse-grained ZM21 alloy. The 0.2% yield strength rose from 180 to 340 MPa after 150 degrees C ECAP processing, while maintaining a fairly high tensile ductility. The ultrafine ZM21 alloy billets were then used for the extrusion of stent precursors having the form of small-size tubes. The grain size after extrusion remained in the submicrometer range while the hardness was revealed to be significantly higher than that of the coarse-grained ZM21 Mg alloy. It was demonstrated that processing of biodegradable Mg stent having an ultrafine-grained microstructure by ECAP and low-temperature extrusion is feasible and that the obtained products feature promising properties. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

引用

页码：8604 / 8610

页数：7

共 27 条

[1] Plastic anisotropy and the role of non-basal slip in magnesium alloy AZ31B [J].