The influence of hydrofluoric acid（HF） treatment on the corrosion behavior of the Mg-0.5Ca alloys was investigated by immersion specimen in sodium hydroxide and HF solutions with various concentrations and durations...The influence of hydrofluoric acid（HF） treatment on the corrosion behavior of the Mg-0.5Ca alloys was investigated by immersion specimen in sodium hydroxide and HF solutions with various concentrations and durations at room temperature.Microstructural evolutions of the specimens were characterized by atomic force microscopy,X-ray diffraction,field-emission scanning electron microscopy.The corrosion resistance was examined through potentiodynamic polarization and immersion test in Kokubo solution.The results revealed that the fluoride treated Mg-0.5Ca alloys produced by immersion in 40% HF provided more uniform,dense and thicker coating layer（12.6 μm） compared with the 35% HF treated specimen.The electrochemical test showed that the corrosion resistance of fluoride treated specimen was 35 times higher compared with the untreated Mg-0.5Ca alloy specimen in Kokubo solution.In vitro degradation rate of the fluoride treated specimens was much lower than untreated Mg-0.5Ca alloy in Kokubo solution.After immersion test the surface of 40% HF treated sample showed a few corrosion dots,while untreated specimens were fully covered by corrosion products and delamination.Fluoride treated Mg-0.5Ca alloy with 40% HF is a promising candidate as biodegradable implants due to its low degradation kinetics and good biocompatibility.展开更多
Magnesium and its alloys have attracted great attention as biocompatible and degradable biomaterials recent years.But their corrosion rate has been proved to be too high,which limits their biomedical application great...Magnesium and its alloys have attracted great attention as biocompatible and degradable biomaterials recent years.But their corrosion rate has been proved to be too high,which limits their biomedical application greatly.In order to improve the corrosion resistance,nano-fluoridated apatite(FA) coating was prepared on ZK60 magnesium alloy by a simple chemical conversion method.The FA coating showed a needle-like morphology.The polarization curves and EIS plots indicated that the FA coating improved the corrosion potential by 125 mV and doubled the polarization resistance of the magnesium alloy,meanwhile decreasing the corrosion current by two orders of magnitude of the substrate in simulated body fluid.The MTT assay indicated good cytocompatibility of L-929 cells with the fluoridated apatite coated magnesium alloy.展开更多
基金supported financially by Ministry of Higher Education of Malaysia under the Vote Number 78610
文摘The influence of hydrofluoric acid（HF） treatment on the corrosion behavior of the Mg-0.5Ca alloys was investigated by immersion specimen in sodium hydroxide and HF solutions with various concentrations and durations at room temperature.Microstructural evolutions of the specimens were characterized by atomic force microscopy,X-ray diffraction,field-emission scanning electron microscopy.The corrosion resistance was examined through potentiodynamic polarization and immersion test in Kokubo solution.The results revealed that the fluoride treated Mg-0.5Ca alloys produced by immersion in 40% HF provided more uniform,dense and thicker coating layer（12.6 μm） compared with the 35% HF treated specimen.The electrochemical test showed that the corrosion resistance of fluoride treated specimen was 35 times higher compared with the untreated Mg-0.5Ca alloy specimen in Kokubo solution.In vitro degradation rate of the fluoride treated specimens was much lower than untreated Mg-0.5Ca alloy in Kokubo solution.After immersion test the surface of 40% HF treated sample showed a few corrosion dots,while untreated specimens were fully covered by corrosion products and delamination.Fluoride treated Mg-0.5Ca alloy with 40% HF is a promising candidate as biodegradable implants due to its low degradation kinetics and good biocompatibility.
基金supported by the Program for Young Excellent Talents in Tongji University (Grant No. 2009KJ003)"Chen Guang" project(Grant No. 10CG21) supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation
文摘Magnesium and its alloys have attracted great attention as biocompatible and degradable biomaterials recent years.But their corrosion rate has been proved to be too high,which limits their biomedical application greatly.In order to improve the corrosion resistance,nano-fluoridated apatite(FA) coating was prepared on ZK60 magnesium alloy by a simple chemical conversion method.The FA coating showed a needle-like morphology.The polarization curves and EIS plots indicated that the FA coating improved the corrosion potential by 125 mV and doubled the polarization resistance of the magnesium alloy,meanwhile decreasing the corrosion current by two orders of magnitude of the substrate in simulated body fluid.The MTT assay indicated good cytocompatibility of L-929 cells with the fluoridated apatite coated magnesium alloy.
