Regensburg 2010 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 44: Materials Design II

MM 44.1: Talk

Wednesday, March 24, 2010, 16:15–16:30, H5

Design strategy for biodegradable Fe-based alloys for medical applications — •Michael Schinhammer, Anja C. Hänzi, Jörg F. Löffler, and Peter J. Uggowitzer — Laboratory of Metal Physics and Technology, Department of Materials, ETH Zürich, Switzerland

Iron is a promising metallic element for bioabsorbable medical implants. The aim of this article is to describe a design strategy for the development of new biodegradable Fe-based alloys for temporary implant applications, in terms of both an enhanced degradation rate compared to pure iron, and suitable strength and ductility. The design strategy is based on electrochemical, microstructural and toxicological considerations. The influence of alloying elements on the electrochemical modification of the Fe matrix and the controlled formation of noble intermetallic phases is deployed. Manganese and palladium have been shown to be suitable alloying additions for this design strategy: Mn lowers the standard electrode potential, while Pd forms noble (Fe,Mn)Pd intermetallics acting as cathodic sites. We discuss the efficiency and the potential of the design approach, and evaluate the resulting characteristics of the new alloys. The newly developed Fe-Mn-Pd alloys reveal an increased degradation rate compared to pure iron. Additionally, the mechanical performance is shown to be adjustable not only by the choice of alloying elements but also by heat treatment procedures; high strength values >1400 MPa at ductility levels >10% can be achieved. Thus, the new alloys offer an attractive combination of electrochemical and mechanical characteristics considered suitable for biodegradable medical applications.