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Design and development of novel MRI compatible zirconium- ruthenium alloys with ultralow magnetic susceptibility.

Li HF, Zhou FY, Li L, Zheng YF - Sci Rep (2016)

Bottom Line: The results demonstrated that alloying with ruthenium into pure zirconium would significantly increase the strength and hardness properties.The corrosion resistance of zirconium-ruthenium alloys increased significantly.Compared with conventional biomedical 316L stainless steel, Co-Cr alloys and Ti-based alloys, the magnetic susceptibilities of the zirconium-ruthenium alloys (1.25 × 10(-6) cm(3)·g(-1)-1.29 × 10(-6) cm(3)·g(-1) for zirconium-ruthenium alloys) are ultralow, about one-third that of Ti-based alloys (Ti-6Al-4V, ~3.5 × 10(-6) cm(3)·g(-1), CP Ti and Ti-6Al-7Nb, ~3.0 × 10(-6) cm(3)·g(-1)), and one-sixth that of Co-Cr alloys (Co-Cr-Mo, ~7.7 × 10(-6) cm(3)·g(-1)).

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China.

ABSTRACT
In the present study, novel MRI compatible zirconium-ruthenium alloys with ultralow magnetic susceptibility were developed for biomedical and therapeutic devices under MRI diagnostics environments. The results demonstrated that alloying with ruthenium into pure zirconium would significantly increase the strength and hardness properties. The corrosion resistance of zirconium-ruthenium alloys increased significantly. High cell viability could be found and healthy cell morphology observed when culturing MG 63 osteoblast-like cells and L-929 fibroblast cells with zirconium-ruthenium alloys, whereas the hemolysis rates of zirconium-ruthenium alloys are <1%, much lower than 5%, the safe value for biomaterials according to ISO 10993-4 standard. Compared with conventional biomedical 316L stainless steel, Co-Cr alloys and Ti-based alloys, the magnetic susceptibilities of the zirconium-ruthenium alloys (1.25 × 10(-6) cm(3)·g(-1)-1.29 × 10(-6) cm(3)·g(-1) for zirconium-ruthenium alloys) are ultralow, about one-third that of Ti-based alloys (Ti-6Al-4V, ~3.5 × 10(-6) cm(3)·g(-1), CP Ti and Ti-6Al-7Nb, ~3.0 × 10(-6) cm(3)·g(-1)), and one-sixth that of Co-Cr alloys (Co-Cr-Mo, ~7.7 × 10(-6) cm(3)·g(-1)). Among the Zr-Ru alloy series, Zr-1Ru demonstrates enhanced mechanical properties, excellent corrosion resistance and cell viability with lowest magnetic susceptibility, and thus is the optimal Zr-Ru alloy system as therapeutic devices under MRI diagnostics environments.

No MeSH data available.


Related in: MedlinePlus

Electrochemical test of annealed pure Zr and Zr–Ru alloys in Hank’s solution, (a) OCP curves, (b) Potentiodynamic polarization curves.
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f5: Electrochemical test of annealed pure Zr and Zr–Ru alloys in Hank’s solution, (a) OCP curves, (b) Potentiodynamic polarization curves.

Mentions: Figure 5 demonstrated the electrochemical test of annealed pure Zr and Zr–Ru alloys in Hank’s solution. According to the open circuit potential (OCP) curves (Fig. 5(a)) and the potentiodynamic polarization curves (Fig. 5(b)), the following parameters including OCP, the corrosion potential (Ecorr), the corrosion current density (icorr) and the breakdown potential (Etran) can be calculated, as listed in Supplementary Information S2. As shown in Fig. 5(a), the OCPs change slowly towards noble potentials and reach relatively stable values for pure Zr and Zr–Ru alloys during 2 h exposure in Hank’s solution. The continuous increase of OCP implies that the passive film spontaneously formed on the metallic surface. By comparing the OCP values (Supplementary Information S2), after alloying with Ru, these alloys show increased OCPs compared to pure Zr, which suggested that Ru additions made the spontaneous passive film more stable thermodynamically, thus providing these Zr–Ru alloys higher corrosion resistance compared to pure Zr. As shown in Fig. 5(b), a passive region was observed on the anodic branch of the polarization curve before the transpassivation occurrence, indicating the thickening and growth of passive film (oxide). It was evident that current plateaus of Zr–Ru alloys were uniformly lower than that of pure Zr, which suggested that the alloying increased the passivity of pure Zr, showing a better protection against dissolving. At more positive potentials, the passive films broke down and the current densities increased rapidly. It can be found in Supplementary Information S2 that all experimental Zr–Ru alloys exhibited lower corrosion current densities compared to pure Zr, which further suggested that Ru alloy additions improved the corrosion resistance of pure Zr. Furthermore, the breakdown potentials (Etran) of Zr–Ru alloys are much higher than that of pure Zr, further indicating the enhanced pitting corrosion resistance by adding the Ru alloying element.


Design and development of novel MRI compatible zirconium- ruthenium alloys with ultralow magnetic susceptibility.

Li HF, Zhou FY, Li L, Zheng YF - Sci Rep (2016)

Electrochemical test of annealed pure Zr and Zr–Ru alloys in Hank’s solution, (a) OCP curves, (b) Potentiodynamic polarization curves.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4836298&req=5

f5: Electrochemical test of annealed pure Zr and Zr–Ru alloys in Hank’s solution, (a) OCP curves, (b) Potentiodynamic polarization curves.
Mentions: Figure 5 demonstrated the electrochemical test of annealed pure Zr and Zr–Ru alloys in Hank’s solution. According to the open circuit potential (OCP) curves (Fig. 5(a)) and the potentiodynamic polarization curves (Fig. 5(b)), the following parameters including OCP, the corrosion potential (Ecorr), the corrosion current density (icorr) and the breakdown potential (Etran) can be calculated, as listed in Supplementary Information S2. As shown in Fig. 5(a), the OCPs change slowly towards noble potentials and reach relatively stable values for pure Zr and Zr–Ru alloys during 2 h exposure in Hank’s solution. The continuous increase of OCP implies that the passive film spontaneously formed on the metallic surface. By comparing the OCP values (Supplementary Information S2), after alloying with Ru, these alloys show increased OCPs compared to pure Zr, which suggested that Ru additions made the spontaneous passive film more stable thermodynamically, thus providing these Zr–Ru alloys higher corrosion resistance compared to pure Zr. As shown in Fig. 5(b), a passive region was observed on the anodic branch of the polarization curve before the transpassivation occurrence, indicating the thickening and growth of passive film (oxide). It was evident that current plateaus of Zr–Ru alloys were uniformly lower than that of pure Zr, which suggested that the alloying increased the passivity of pure Zr, showing a better protection against dissolving. At more positive potentials, the passive films broke down and the current densities increased rapidly. It can be found in Supplementary Information S2 that all experimental Zr–Ru alloys exhibited lower corrosion current densities compared to pure Zr, which further suggested that Ru alloy additions improved the corrosion resistance of pure Zr. Furthermore, the breakdown potentials (Etran) of Zr–Ru alloys are much higher than that of pure Zr, further indicating the enhanced pitting corrosion resistance by adding the Ru alloying element.

Bottom Line: The results demonstrated that alloying with ruthenium into pure zirconium would significantly increase the strength and hardness properties.The corrosion resistance of zirconium-ruthenium alloys increased significantly.Compared with conventional biomedical 316L stainless steel, Co-Cr alloys and Ti-based alloys, the magnetic susceptibilities of the zirconium-ruthenium alloys (1.25 × 10(-6) cm(3)·g(-1)-1.29 × 10(-6) cm(3)·g(-1) for zirconium-ruthenium alloys) are ultralow, about one-third that of Ti-based alloys (Ti-6Al-4V, ~3.5 × 10(-6) cm(3)·g(-1), CP Ti and Ti-6Al-7Nb, ~3.0 × 10(-6) cm(3)·g(-1)), and one-sixth that of Co-Cr alloys (Co-Cr-Mo, ~7.7 × 10(-6) cm(3)·g(-1)).

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China.

ABSTRACT
In the present study, novel MRI compatible zirconium-ruthenium alloys with ultralow magnetic susceptibility were developed for biomedical and therapeutic devices under MRI diagnostics environments. The results demonstrated that alloying with ruthenium into pure zirconium would significantly increase the strength and hardness properties. The corrosion resistance of zirconium-ruthenium alloys increased significantly. High cell viability could be found and healthy cell morphology observed when culturing MG 63 osteoblast-like cells and L-929 fibroblast cells with zirconium-ruthenium alloys, whereas the hemolysis rates of zirconium-ruthenium alloys are <1%, much lower than 5%, the safe value for biomaterials according to ISO 10993-4 standard. Compared with conventional biomedical 316L stainless steel, Co-Cr alloys and Ti-based alloys, the magnetic susceptibilities of the zirconium-ruthenium alloys (1.25 × 10(-6) cm(3)·g(-1)-1.29 × 10(-6) cm(3)·g(-1) for zirconium-ruthenium alloys) are ultralow, about one-third that of Ti-based alloys (Ti-6Al-4V, ~3.5 × 10(-6) cm(3)·g(-1), CP Ti and Ti-6Al-7Nb, ~3.0 × 10(-6) cm(3)·g(-1)), and one-sixth that of Co-Cr alloys (Co-Cr-Mo, ~7.7 × 10(-6) cm(3)·g(-1)). Among the Zr-Ru alloy series, Zr-1Ru demonstrates enhanced mechanical properties, excellent corrosion resistance and cell viability with lowest magnetic susceptibility, and thus is the optimal Zr-Ru alloy system as therapeutic devices under MRI diagnostics environments.

No MeSH data available.


Related in: MedlinePlus