摘要
Magnesium and its alloys are promising biomaterials due to their biocompatibility and osteoinduction. The plasticity and corrosion resistance of commercial magnesium alloys cannot meet the requirements for degradable biomaterials completely at present. Particularly, the alkalinity in the microenvironment surrounding the degradation, implants, resulting from the arises a major concern. Micro arc oxidation （MAO） and poly（lactic acid） （PLA） composite （MAO/PLA）coating on biomedical Mg- 1.21Li-1.12Ca-1.0Y alloy was prepared to manipulate pH variation in an appropriate range. Surface morphologies were discerned using SEM EMPA. AM corrosion resistance was evaluated via electrochemical Polarization and impedance and hydrogen volumetric method. The results demonstrated that the MAO coating predomlnantly consisted of MgO, Mg2SiO4 and YzO3. The composite coating markedly improved the corrosion resistance of the alloy. The rise in solution pH for the MAO/PLA coating was tailored to a favorable range of 7.5-7.8 The neutrallzation caused by the alkalinity of MAO and Mg substrate and acidification of PLA was probed. The reSult designates that MAOI PLA composite coating on Mg-1.21Li-1.12Ca-1.0Y alloys may be a promising biomedical coating.
Magnesium and its alloys are promising biomaterials due to their biocompatibility and osteoinduction. The plasticity and corrosion resistance of commercial magnesium alloys cannot meet the requirements for degradable biomaterials completely at present. Particularly, the alkalinity in the microenvironment surrounding the degradation, implants, resulting from the arises a major concern. Micro arc oxidation （MAO） and poly（lactic acid） （PLA） composite （MAO/PLA）coating on biomedical Mg- 1.21Li-1.12Ca-1.0Y alloy was prepared to manipulate pH variation in an appropriate range. Surface morphologies were discerned using SEM EMPA. AM corrosion resistance was evaluated via electrochemical Polarization and impedance and hydrogen volumetric method. The results demonstrated that the MAO coating predomlnantly consisted of MgO, Mg2SiO4 and YzO3. The composite coating markedly improved the corrosion resistance of the alloy. The rise in solution pH for the MAO/PLA coating was tailored to a favorable range of 7.5-7.8 The neutrallzation caused by the alkalinity of MAO and Mg substrate and acidification of PLA was probed. The reSult designates that MAOI PLA composite coating on Mg-1.21Li-1.12Ca-1.0Y alloys may be a promising biomedical coating.
基金
This research was financially supported by the National Natural Science Foundation of China （Grant No. 51241001）, Shandong Provincial Natural Science Foundation, China （ZR2011E MM004）, SDUST Research Fund （2014TDJH 104）, Joint innovative Center for Safe and Effective Mining Technology and Equipment of Coal Resources, and Shandong Province as well as Taishan Scholarship Project of Shandong Province （TS20110828）. Thanks go to Prof. Rong-Shi Chen and the members of his group at Institute of Metals Research, Chinese Academy of Sciences for the preparation of the ingots.
