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      https://www.ias.ac.in/article/fulltext/boms/036/06/1103-1113

    • Keywords

       

      Thermal analysis; corrosion behaviour; microstructure.

    • Abstract

       

      The thermal parameters of Mg–𝑥Zn cast alloys with 0.5–9 wt% Zn were evaluated by using computer aided cooling curve thermal analysis (CA–CCTA), whereas the corrosion behaviour was investigated by potentiodynamic polarization and immersion tests. Thermal analysis results revealed that the dendrite coherency temperature (𝑇DCP) decreased from 642.2 to 600 °C with the addition of Zn from 0.5 to 9 wt%. The liquid fraction at coherency point ($f^{\text{DCP}}_{\text{L}}$) increased by 72% when Zn was increased up to 9 wt%. MgZn intermetallic phase was observed in samples with <3 wt% Zn. At higher percentages of Zn, the Mg51Zn20 intermetallic phase was also detected in addition to 𝛼-Mg and MgZn by first derivative cooling curves under non-equilibrium solidification. All these phases were observed along the grain boundary when Zn was rejected from the solid/liquid interface and enriched in the triple conjunction of grain boundary. The grain size decreased from 185.2 to 71.5 𝜇m when Zn content was increased. The addition of Zn content had a significant effect on the corrosion rate and the corresponding mechanisms. The corrosion rate decreased from 2.1 to 1.81 mmpy as Zn content increased from 0.5 to 3 wt%; afterwards, however, this value increased with further increase of Zn. Mg–3Zn also had the lowest degradation rate and highest corrosion resistance which can be fully utilized for biodegradable orthopedic applications.

    • Author Affiliations

       

      Amir Fereidouni Lotfabadi1 2 Mohd Hasbullah Idris2 Ali Ourdjini2 Mohammed Rafiq Abdul Kadir3 Saeed Farahany2 Hamid Reza Bakhsheshi-Rad2

      1. Department of Manufacturing and Industrial Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor, Malaysia
      2. Department of Materials Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor, Malaysia
      3. Department of Biomechanics and Biomedical Materials, Faculty of Biomedical Engineering and Health Sciences, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor, Malaysia
    • Dates

       
  • Bulletin of Materials Science | News

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