Print Email Facebook Twitter Forming of magnesium alloy microtubes in the fabrication of biodegradable stents Title Forming of magnesium alloy microtubes in the fabrication of biodegradable stents Author Wang, L. Fang, G. Qian, L. Leeflang, M.A. Duszczyk, J. Zhou, J. Faculty Mechanical, Maritime and Materials Engineering Department Biomechanical Engineering Date 2014-11-03 Abstract Magnesium alloys have, in recent years, been recognized as highly promising biodegradable materials, especially for vascular stent applications. Forming of magnesium alloys into high-precision thin-wall tubes has however presented a technological barrier in the fabrication of vascular stents, because of the poor workability of magnesium at room temperature. In the present study, the forming processes, i.e., hot indirect extrusion and multi-pass cold drawing were used to fabricate seamless microtubes of a magnesium alloy. The magnesium alloy ZM21 was selected as a representative biomaterial for biodegradable stent applications. Microtubes with an outside diameter of 2.9 mm and a wall thickness of 0.2 mm were successfully produced at the fourth pass of cold drawing without inter-pass annealing. Dimensional evaluation showed that multi-pass cold drawing was effective in correcting dimensional non-uniformity arising from hot indirect extrusion. Examinations of the microstructures of microtubes revealed the generation of a large number of twins as a result of accumulated work hardening at the third and fourth passes of cold drawing, corresponding to the significantly raised forming forces. The work demonstrated the viability of the forming process route selected for the fabrication of biodegradable magnesium alloy microtubes. Subject vascular stentmicrotubemagnesium alloyextrusiondrawing To reference this document use: http://resolver.tudelft.nl/uuid:8b509ddb-ca42-4420-9b35-bc5543ae0d60 DOI https://doi.org/10.1016/j.pnsc.2014.08.006 Publisher Elsevier ISSN 1002-0071 Source Progress in Natural Science: Materials International, 24 (5), 2014 Part of collection Institutional Repository Document type journal article Rights (c) 2014 Chinese Materials Research Society Files PDF Leeflang_2014.pdf 1.75 MB Close viewer /islandora/object/uuid:8b509ddb-ca42-4420-9b35-bc5543ae0d60/datastream/OBJ/view