Abstract
Vascular stents are used to restore blood flow in stenotic arteries, and at present the implantation of a stent is the preferred revascularisation method for treating coronary artery disease, as the introduction of drug eluting stents (DESs) has lead to a significant improvement in the clinical outcome of coronary stenting. However the mechanical limits of stents are being tested when they are deployed in severe cases. In this study we aimed to show (by a combination of experimental tests and crystal plasticity finite element models) that the ductility of stainless steel stent struts can be increased by optimising the grain structure within micro-scale stainless steel stent struts. The results of the study show that within the specimen size range 55 to 190 μ m ductility was not dependent on the size of the stent strut when the grain size maximised. For values of the ratio of cross sectional area to characteristic grain length less than 1000, ductility was at a minimum irrespective of specimen size. However, when the ratio of cross sectional area to characteristic grain length becomes greater than 1000 an improvement in ductility occurs, reaching a plateau when the ratio approaches a value characteristic of bulk material properties. In conclusion the ductility of micro-scale stainless steel stent struts is sensitive to microstructure and can be improved by reducing the grain size.
Article PDF
Similar content being viewed by others
References
E. J. TOPOL, New Engl. J. Med. 339 (1998) 1702.
A. HALKIN and G. W. STONE, J. of Interventional Cardiology 17 (2004) 271.
R. T. VAN DOMBURG, P. A. LEMOS, J. M. TAKKENBERG, T. K. K. LIU and L. A. VAN HERWERDEN, et al., Eur. Heart J. 2005 (in press).
G. SIANOS, S. HOFMA, J. M. R. LIGTHART, F. SAIA, A. HOYE, P. A. LEMOS and P. W. SERRUYS, Catherization and Cardiovascular Interventions 61 (2004) 111.
D. R. HOLMES and D. J. KEREIAKES, Reviews in Cardiovascular Medicine 6(Suppl. 1) (2005) 31.
B. P. MURPHY, P. SAVAGE, P. E. MCHUGH and D. F. QUINN, Ann. Biomed. Eng. 31 (2003) 686.
J. PACHE, A. KASTRATI, J. MEHILLI, H. SCVHLEN, F. DOTZER and J. HAUSLEITER, et al., Journal of the American College of Cardiology 41 (2003) 1283.
A. KASTRATI, J. MEHILLI, J. DIRSCHINGER, F. DOTZER and H. SCVHLEN, et al. Circulation 103 (2001) 2816.
S. Z. H. RITTERSMA, R. J. DE WINTER, K. T. KOCH, M. BAX and C. E. SCHOTBORGH, et al. American Journal of Cardiology 93 (2004) 477.
C. SIMON, J. C. PALMAZ and E. A. SPRAGUE, Journal of Long-Term Effects of Medical Implants 10(1/2) (2000) 143.
P. W. SERRUYS and M. J. B. KUTRYK, in “Handbook of Coronary Stents” (Martin Dunitz Ltd., London 2000)
D. MÖLLER, W. REIMERS, A. PYZALLA and A. FISCHER, J. Biomed. Mater. Res. 58 (2001) 69.
Y. KOHNO, A. KOHYAMA, M. L. HAMILTON, T. HIROSE, Y. KATOH and F. A. GARNER, J. Nucl. Mater. 283–287 (2000) 1014.
P. SAVAGE, B. P. O'DONNELL, P. E. MCHUGH, B. P. MURPHY and D. F. QUINN, Ann. Biomed. Eng. 32 (2004) 202.
C. MEYER-KOBBE and B. H. HINRICHS, Medical Device Technology 14(1) (2003) 20.
D. PIERCE, R. J. ASARO and A. NEEDLEMAN, Acta Metall. Mater. 31 (1983) 1951.
Y. HUANG, A User-Material Subroutine Incorporating Single Crystal Plasticity in the ABAQUS Finite Element Program. Harvard University Report, MECH 178 1991.
J. P. MCGARRY, B. P. O'DONNELL, P. E. MCHUGH and J. G. MCGARRY, Comput. Mater. Sci. 31 (2004) 421.
X. YOU, T. CONNOLLEY and P. E. MCHUGH, Manuscript in Preparation, 2005.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Murphy, B.P., Cuddy, H., Harewood, F.J. et al. The influence of grain size on the ductility of micro-scale stainless steel stent struts. J Mater Sci: Mater Med 17, 1–6 (2006). https://doi.org/10.1007/s10856-006-6323-5
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s10856-006-6323-5