MRI-compatible Nb–60Ta–2Zr alloy for vascular stents: Electrochemical corrosion behavior in simulated plasma solution

MRI compatibility of several early transition metal based alloys and its influencing factors

“…Recently, from a materials perspective, it is of considerable interest to develop MRI‐compatible alloys based on the elements with lower magnetic susceptibility, and simultaneously to meet the requirements of mechanical properties, corrosion resistance and biocompatibility. Such tissue‐susceptibility matched metals have been reported in several alloy systems including the Cu‐Sn, Au‐Pt‐Nb, Zr‐Mo, Zr‐Nb, Nb‐Ta‐W‐Zr, and Nb‐Ta‐Zr …”

“…Therefore, designing MRI‐compatible metals chemically based on the ETM is a more promising effort. In fact, it has been presented in several studies already . Simultaneously, it is also required to ensure tolerable biocompatibility and adequate mechanical properties of the materials.…”

“…Microstructures and mechanical properties of annealed Nb–60Ta–2Zr (wt. %) alloy which was fabricated using the electron beam melting (EBM) technique were presented in our previous work . Commercial pure tantalum (99.98%) and a L605 Co‐Cr alloy (ASTM F90) with annealing states were obtained in plate and bulk form, respectively.…”

“…These alloys are expected to have potential application as dental or orthopedic implants. The Nb–60Ta–2Zr alloy was designed for vascular stents in terms of the requirement of mechanical properties, corrosion resistance, biocompatibility and lower magnetic susceptibility . With the agarose gel phantom in which the metal cylinders were embedded, two‐dimensional (2D) MR images were taken in the manner of FSE and GRE sequences.…”

“…Such tissue-susceptibility matched metals have been reported in several alloy systems including the Cu-Sn, 16 Au-Pt-Nb, 17 Zr-Mo, 18 Zr-Nb, [19][20][21] Nb-Ta-W-Zr, 22 and Nb-Ta-Zr. [23][24][25] In this work, several desirable MRI-compatible alloys were selected to investigate their susceptibility artifacts in MRI, including the Zr-20Nb, near-equiatomic high-entropy (TiZrNb-Ta) 90 Mo 10 and Nb-60Ta-2Zr, together with pure tantalum and a Co-Cr alloy (L605) for comparison. The binary Zr-20Nb alloy was reported to possess a good combination of mechanical properties and lower magnetic susceptibility, such as r y 5 640 MPa, elongation d 5 23%, Young's modulus of 50 GPa and mass magnetic susceptibility v51.4 3 10 2 6 cm 3 /g at 0.35 T. 20 While the newly-developed (TiZrNbTa) 90 Mo 10 high-entropy alloy (HEA) exhibited a high strength (r y 5 1300 MPa) and high corrosion resistance under simulated physiological medium.…”