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MECHANICAL PROPERTIES AND CORROSION BEHAVIORS OF AGED Ti-4Mo-4Cr-X (X = Sn, V, Zr) ALLOYS FOR METALLIC BIOMATERIALS

  • KWANGMIN LEE (CHONNAM NATIONAL UNIVERSITY, SCHOOL OF MATERIALS SCIENCE & ENGINEERING) ;
  • GUNHEE LEE (21CENTURY MEDICAL CO. LTD.)
  • Published : 20200000

Abstract

The purpose of this study was to investigate the mechanical properties of beta type aged Ti-4Mo-4Cr-X (X = V, Sn, Zr) quaternary alloy for use as a cardiovascular stent. Titanium (Ti) alloys were fabricated using a vacuum arc remelting furnace process. To homogenize the specimens of each composition and remove the micro segregation, all cast specimens were subjected to homogenization at 850℃ for 4 h, which was 100℃ higher than the β-transus temperature of 750℃. The tensile strength and elongation of the aged Ti-4Mo-4Cr-X (X = V, Sn, Zr) alloys were increased as compared to the homogenized alloys. In addition, many α/β interface boundaries formed after aging treatment at 450℃, which acted as inhibitors of strain and caused an increase in tensile strength. The elongation of Ti-4Mo-4Cr-X alloys consisting of α + β phases after aging treatment was improved by greater than 30%. Results of a potentiodynamic polarization test showed that the lowest current density of Ti-4Mo-4Cr-4Sn with 1.05 × 10-8 A/cm2 was obtained. The present Ti-4Mo-4Cr-X alloys showed better corrosion characteristics as compared to the 316L stainless steel and L605 (Co-Cr alloy) cardiovascular stent alloys.

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Acknowledgement

This research was supported by the Basic Science Research Program of the National Research Foundation of Korea (NRF) funded by the Ministry of Education (No. 2015R1D1A1A01056861).