Acta Metallurgica Sinica (English Letters) ›› 2019, Vol. 32 ›› Issue (10): 1195-1206.DOI: 10.1007/s40195-019-00892-5

Special Issue: 2019年镁合金专辑

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Biodegradation Behavior of Coated As-Extruded Mg–Sr Alloy in Simulated Body Fluid

Ming-Chun Zhao1, Ying-Chao Zhao1, Deng-Feng Yin1(), Shuo Wang1, Yong-Ming Shangguan2, Chao Liu1, Li-Li Tan2, Ci-Jun Shuai1, Ke Yang2, Andrej Atrens3   

  1. 1 School of Materials Science and Engineering, Central South University, Changsha 410083, China
    2 Institute of Metal Research, Chinese Academy of Sciences,Shenyang 110016, China
    3 Division of Materials, The University of Queensland, Brisbane, QLD 4072, Australia
  • Received:2018-09-20 Revised:2019-03-04 Online:2019-10-10 Published:2019-09-17
  • About author:

    1The authors equally contributed to this work.

Abstract:

As-extruded Mg-Sr alloy, a kind of promising biodegradable biomedical material, was coated using micro-arc oxidation and also using a phosphate conversion coating. The corrosion behaviors were investigated using Hanks’ solution. The corrosion of the as-extruded Mg-Sr alloy became more serious with increasing immersion time; that is, the corrosion pits became more numerous, larger and deeper. The micro-arc oxidation coating and the phosphate conversion coating were effective in improving the corrosion resistance of the as-extruded Mg-Sr alloy. The micro-arc oxidation coating was much more effective. Moreover, the as-extruded Mg-Sr alloy and the coated as-extruded Mg-Sr alloy exhibited lower corrosion rates than the as-cast Mg-Sr alloy and the corresponding coated as-cast Mg-Sr alloy, indicating that the corrosion properties of the coated samples are dependent on their substrates. The finer microstructure of the substrate of the as-extruded condition corroded much slower. The corrosion resistance of the coated Mg-Sr alloy depended on the coating itself and on the microstructure of the substrate.

Key words: Mg alloy, Micro-arc oxidation coating, Phosphate conversion coating, Biodegradation, Corrosion resistance