Mg-5Zn-0.3Ca/nHA biocomposites were prepared from pure Mg,Zn,Ca and nano-hydroxyapatite(nHA)powders by powder metallurgy method.The effect of various mass fractions of nHA(1%,2.5%,5%)as reinforcement on the corrosion ...Mg-5Zn-0.3Ca/nHA biocomposites were prepared from pure Mg,Zn,Ca and nano-hydroxyapatite(nHA)powders by powder metallurgy method.The effect of various mass fractions of nHA(1%,2.5%,5%)as reinforcement on the corrosion properties of Mg-5Zn-0.3Ca alloy was investigated.The corrosion resistance of biocomposite samples was investigated by immersion tests and electrochemical techniques in SBF solution.The results showed that the corrosion resistance of Mg alloy was improved by adding 1%and 2.5%nHA.Bioactive nHA motivated the formation of stable phosphate and carbonate layers on surface and improved corrosion resistance of nanocomposites.However,addition of large contents of nHA in Mg alloy as reinforcement increased the density of this precipitated layer,so gases produced from localized corrosion were accumulated underneath this layer and decreased its adhesiveness and lowered its corrosion resistance.Indirect cytotoxicity evaluation for Mg alloy and its nanocomposites also showed that their extraction was not toxic and nanocomposite with 1%nHA indicated almost similar behavior as negative control.展开更多
In the present study,a new biodegradable Mg-Zn-Cu magnesium alloy was introduced for biological applications.The microstructural analysis showed the formation of Mg Zn Cu intermetallics for the Mg-2Zn-0.1Cu alloy and ...In the present study,a new biodegradable Mg-Zn-Cu magnesium alloy was introduced for biological applications.The microstructural analysis showed the formation of Mg Zn Cu intermetallics for the Mg-2Zn-0.1Cu alloy and also the Mg(Zn,Cu);compounds for the Mg-2 Zn alloys with higher Cu contents.Moreover,the hot extrusion was applied for the grain refinement and changing the distribution of intermetallics.In vitro immersion tests,electrochemical and corroded surface analyses represented the enhancement of corrosion resistance with 0.1 wt.%Cu addition.Furthermore,the extruded alloys demonstrated more corrosion resistance behavior than that of the cast alloys.By considering the improved tensile properties of Mg-2Zn-0.1Cu alloy,this alloy was regarded as the potential candidate for use as the biodegradable magnesium implant.展开更多
文摘Mg-5Zn-0.3Ca/nHA biocomposites were prepared from pure Mg,Zn,Ca and nano-hydroxyapatite(nHA)powders by powder metallurgy method.The effect of various mass fractions of nHA(1%,2.5%,5%)as reinforcement on the corrosion properties of Mg-5Zn-0.3Ca alloy was investigated.The corrosion resistance of biocomposite samples was investigated by immersion tests and electrochemical techniques in SBF solution.The results showed that the corrosion resistance of Mg alloy was improved by adding 1%and 2.5%nHA.Bioactive nHA motivated the formation of stable phosphate and carbonate layers on surface and improved corrosion resistance of nanocomposites.However,addition of large contents of nHA in Mg alloy as reinforcement increased the density of this precipitated layer,so gases produced from localized corrosion were accumulated underneath this layer and decreased its adhesiveness and lowered its corrosion resistance.Indirect cytotoxicity evaluation for Mg alloy and its nanocomposites also showed that their extraction was not toxic and nanocomposite with 1%nHA indicated almost similar behavior as negative control.
文摘In the present study,a new biodegradable Mg-Zn-Cu magnesium alloy was introduced for biological applications.The microstructural analysis showed the formation of Mg Zn Cu intermetallics for the Mg-2Zn-0.1Cu alloy and also the Mg(Zn,Cu);compounds for the Mg-2 Zn alloys with higher Cu contents.Moreover,the hot extrusion was applied for the grain refinement and changing the distribution of intermetallics.In vitro immersion tests,electrochemical and corroded surface analyses represented the enhancement of corrosion resistance with 0.1 wt.%Cu addition.Furthermore,the extruded alloys demonstrated more corrosion resistance behavior than that of the cast alloys.By considering the improved tensile properties of Mg-2Zn-0.1Cu alloy,this alloy was regarded as the potential candidate for use as the biodegradable magnesium implant.
