Convention Center: 264 (Ernest N. Morial Convention Center)
Dr. Anna Jarzębska
,
Institute of Metallurgy and Materials Science Polish Academy of Sciences, Kraków, Poland
Dr. Łukasz Maj
,
Institute of Metallurgy and Materials Science Polish Academy of Sciences, Kraków, Poland
Ms. Magdalena Wróbel
,
Institute of Metallurgy and Materials Science Polish Academy of Sciences, Kraków, Poland
Mr. Daniel Wojtas
,
Institute of Metallurgy and Materials Science Polish Academy of Sciences, Kraków, Poland
Dr. Agnieszka Bigos
,
Institute of Metallurgy and Materials Science Polish Academy of Sciences, Kraków, Poland
Dr. Monika Bugajska
,
Institute of Metallurgy and Materials Science Polish Academy of Sciences, Kraków, Poland
Dr. Klaudia Trembecka-Wójciga
,
Institute of Metallurgy and Materials Science Polish Academy of Sciences, Kraków, Poland
Mr. Karol Janus
,
Institute of Metallurgy and Materials Science Polish Academy of Sciences, Kraków, Poland
Prof. Magdalena Bieda
,
Institute of Metallurgy and Materials Science Polish Academy of Sciences, Kraków, Poland
Dr. Sylwia Przybysz-Gloc
,
Institute of High Pressure Physics of the Polish Academy of Sciences, Warsaw, Poland
Zinc alloys subjected to hydrostatic extrusion preceded by hot extrusion exhibits high mechanical properties meeting restricted design criteria for bioabsorbable cardiac stents. Excellent mechanical properties combined with optimal corrosion rate makes them very promising candidates for producing temporary implants. However, low recrystallization temperature of zinc, being close to a room temperature, can pose a problem due to the fact of body temperature. Another concern is their mechanical integrity during the early stages of implantation. Thus, it is important to evaluate how increased temperature and progressing degradation affect the mechanical behavior of low-alloyed zinc.
In this study pure Zn and low-alloyed ZnMg, ZnMgCu after hot extrusion (at 250°C) followed by multi-pass hydrostatic extrusion were subjected to uniaxial tensile and compression tests performed on Shimadzu Autograph AG-X plus testing machine. In order to simulate human body conditions, the tensile tests were carried out at 37°C. For assessment of degradation effect on strength and plasticity, the samples were exposed to Hanks solution at 37°C up to 30 days. After the immersion, the samples were compressed. Microstructural observations were carried out with FEI Quanta 3D FEG/SEM microscope equipped with EBSD Genesis TSL system for EBSD data acquisition, in order to follow the changes and correlate the microstructure with the mechanical behavior of the materials.
The results revealed that alloying additions increased recrystallization temperature of zinc what allowed to maintain initial microstructure and, as a consequence, preserve mechanical properties on similar level as that measured at room temperature. The compression test of the immersed samples did not reveal any significant changes in mechanical properties as well. The conducted research leads to conclusions that low-alloyed zinc after hybrid plastic deformation is suitable for producing bioabsorbable stents.
Acknowledgments
This work was financially supported by the National Centre for Research and Development, project no. LIDER/54/0229/L-11/19/NCBR/2020
