Premium
Evaluation of wrought Zn–Al alloys (1, 3, and 5 wt % Al) through mechanical and in vivo testing for stent applications
Author(s) -
Bowen Patrick K.,
Seitz JanMarten,
Guillory Roger J.,
Braykovich Jacob P.,
Zhao Shan,
Goldman Jeremy,
Drelich Jaroslaw W.
Publication year - 2018
Publication title -
journal of biomedical materials research part b: applied biomaterials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.665
H-Index - 108
eISSN - 1552-4981
pISSN - 1552-4973
DOI - 10.1002/jbm.b.33850
Subject(s) - materials science , corrosion , intergranular corrosion , zinc , metallurgy , ultimate tensile strength , elongation , aluminium , microstructure
Special high grade zinc and wrought zinc‐aluminum (Zn–Al) alloys containing up to 5.5 wt % Al were processed, characterized, and implanted in rats in search of a new family of alloys with possible applications as bioabsorbable endovascular stents. These materials retained roll‐induced texture with an anisotropic distribution of the second‐phase Al precipitates following hot‐rolling, and changes in lattice parameters were observed with respect to Al content. Mechanical properties for the alloys fell roughly in line with strength (190–240 MPa yield strength; 220–300 MPa ultimate tensile strength) and elongation (15–30%) benchmarks, and favorable elastic ranges (0.19–0.27%) were observed. Intergranular corrosion was observed during residence of Zn–Al alloys in the murine aorta, suggesting a different corrosion mechanism than that of pure zinc. This mode of failure needs to be avoided for stent applications because the intergranular corrosion caused cracking and fragmentation of the implants, although the composition of corrosion products was roughly identical between non‐ and Al‐containing materials. In spite of differences in corrosion mechanisms, the cross‐sectional reduction of metals in murine aorta was nearly identical at 30–40% and 40–50% after 4.5 and 6 months, respectively, for pure Zn and Zn–Al alloys. Histopathological analysis and evaluation of arterial tissue compatibility around Zn–Al alloys failed to identify areas of necrosis, though both chronic and acute inflammatory indications were present. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 245–258, 2018.