Direct electrodeposition of quarternary Mg-Zn-Li-Ca alloys on a molybdenum electrode from LiCl-KCl-MgCl2-ZnCl2-CaCl2 melts at 943 K was investigated.Cyclic voltammograms（CVs） show that the deposition potential of Li...Direct electrodeposition of quarternary Mg-Zn-Li-Ca alloys on a molybdenum electrode from LiCl-KCl-MgCl2-ZnCl2-CaCl2 melts at 943 K was investigated.Cyclic voltammograms（CVs） show that the deposition potential of Li shifts in a positive direction after adding MgCl2,ZnCl2 and CaCl2.Chronopotentiometric measurements indicate that the codepositon of Mg,Li,Zn,and Ca occurs at current densities lower than-1.55 A/cm2.X-ray diffraction（XRD） indicates that Mg-Zn-Li-Ca alloys with different phases were prepared via galvanostatic electrolysis.The microstructures of typical phase of Mg-Zn-Li-Ca alloys were characterized by optical microscopy（OM） and scanning electron microscopy（SEM）.The analysis of energy dispersive spectrometry（EDS） shows that elements of Mg and Ca distribute homogeneously in the Mg-Zn-Li-Ca alloy.However,element Zn mainly locates at the edges of the domain.展开更多
Zn-Li alloys are considered promising candidate materials for biodegradable orthopedic implant applications due to their high mechanical performance and good biocompatibility.However,the presence of a large number of ...Zn-Li alloys are considered promising candidate materials for biodegradable orthopedic implant applications due to their high mechanical performance and good biocompatibility.However,the presence of a large number of second-phase particles in this class of Zn alloys can lead to severe localized degradation due to micro-galvanic corrosion,which is detrimental to the mechanical integrity of the alloys during tissue healing in the human body.In this study we report ultrahigh strength,uniform corrosion,good cytocompatibility,and effective antibacterial ability in Zn-x Li(x=0.3,0.5,0.7;wt%)alloys achieved through supersaturated solid solution treatment(SSST)at 375℃ under ultrahigh pressure of 3 GPa.A high concentration of β-LiZn_(4)phases coexisted with the-Zn matrix in the as-cast Zn-x Li alloys,whereas almost all the Li dissolved into the-Zn matrix of SSST counterparts.The yield strength was 437 MPa for SSST Zn-0.3Li,592 MPa for SSST Zn-0.5 Li and 686 MPa for SSST Zn-0.7Li.The SSST Zn-Li alloys showed uniform degradation with remarkably reduced degradation rates compared to their as-cast counterparts.The 25% concentration extracts of the Zn-x Li alloys demonstrated no cytotoxicity toward MC3T3-E1 cells,and the alloys exhibited effective antibacterial ability agains methicillin-resistant staphylococcus aureus.展开更多
Fabricated through a newly developed hot-warm rolling process,Zn-0.8 Li(wt%)alloy has ideal strength and ductility far beyond the mechanical benchmark of materials for biodegradable stents.Precipitation of needle-like...Fabricated through a newly developed hot-warm rolling process,Zn-0.8 Li(wt%)alloy has ideal strength and ductility far beyond the mechanical benchmark of materials for biodegradable stents.Precipitation of needle-like Zn in primary p-LiZn4 phase is observed in Zn-Li alloy for the first time.Orientation relationship between them can be described as[1-213]β//[2-1-10](Zn),(10-10)βabout 4.5°from(0002)(Zn).Zn grains with an average size of 640 nm exhibit strong basal texture,detected by transmission electron back-scatter diffraction.Li distribution is determined by three-dimensional atom probe,which reveals the formation of nano-sized metastableα-Li2Zn3 precipitates with a number density of 7.16×10^22 m^-3.The fine lamellar Zn+β-LiZn4 structure,sub-micron grains and the nano-sized precipitates contribute to the superior mechanical properties.展开更多
基金Project(2011AA03A409) supported by the High-tech Research and Development Program of ChinaProjects(21103033,21101040, 21173060,91226201) supported by the National Natural Science Foundation of China+1 种基金Project(HEUCF20130012) supported by the Fundamental Research Funds for the Central Universities,ChinaProject(1253G016) supported by the Foundation for University Key Teacher of Heilongjiang Province of China
文摘Direct electrodeposition of quarternary Mg-Zn-Li-Ca alloys on a molybdenum electrode from LiCl-KCl-MgCl2-ZnCl2-CaCl2 melts at 943 K was investigated.Cyclic voltammograms（CVs） show that the deposition potential of Li shifts in a positive direction after adding MgCl2,ZnCl2 and CaCl2.Chronopotentiometric measurements indicate that the codepositon of Mg,Li,Zn,and Ca occurs at current densities lower than-1.55 A/cm2.X-ray diffraction（XRD） indicates that Mg-Zn-Li-Ca alloys with different phases were prepared via galvanostatic electrolysis.The microstructures of typical phase of Mg-Zn-Li-Ca alloys were characterized by optical microscopy（OM） and scanning electron microscopy（SEM）.The analysis of energy dispersive spectrometry（EDS） shows that elements of Mg and Ca distribute homogeneously in the Mg-Zn-Li-Ca alloy.However,element Zn mainly locates at the edges of the domain.
基金financially supported by Hunan Provincial Natural Science Foundation of China(No.2023JJ40626)the National Natural Science Foundation of China(Nos.11872053 and 51971190)+1 种基金the Post-graduate Scientific Research Innovation Project of Hunan Province(No.CX20210625)the Australian Research Council(ARC)through the Discovery Project(No.DP210101862)。
文摘Zn-Li alloys are considered promising candidate materials for biodegradable orthopedic implant applications due to their high mechanical performance and good biocompatibility.However,the presence of a large number of second-phase particles in this class of Zn alloys can lead to severe localized degradation due to micro-galvanic corrosion,which is detrimental to the mechanical integrity of the alloys during tissue healing in the human body.In this study we report ultrahigh strength,uniform corrosion,good cytocompatibility,and effective antibacterial ability in Zn-x Li(x=0.3,0.5,0.7;wt%)alloys achieved through supersaturated solid solution treatment(SSST)at 375℃ under ultrahigh pressure of 3 GPa.A high concentration of β-LiZn_(4)phases coexisted with the-Zn matrix in the as-cast Zn-x Li alloys,whereas almost all the Li dissolved into the-Zn matrix of SSST counterparts.The yield strength was 437 MPa for SSST Zn-0.3Li,592 MPa for SSST Zn-0.5 Li and 686 MPa for SSST Zn-0.7Li.The SSST Zn-Li alloys showed uniform degradation with remarkably reduced degradation rates compared to their as-cast counterparts.The 25% concentration extracts of the Zn-x Li alloys demonstrated no cytotoxicity toward MC3T3-E1 cells,and the alloys exhibited effective antibacterial ability agains methicillin-resistant staphylococcus aureus.
基金supported financially by the National Key R&D Program of China (No.2016YFC1102500)the National Natural Science Foundation of China (No.51871020)
文摘Fabricated through a newly developed hot-warm rolling process,Zn-0.8 Li(wt%)alloy has ideal strength and ductility far beyond the mechanical benchmark of materials for biodegradable stents.Precipitation of needle-like Zn in primary p-LiZn4 phase is observed in Zn-Li alloy for the first time.Orientation relationship between them can be described as[1-213]β//[2-1-10](Zn),(10-10)βabout 4.5°from(0002)(Zn).Zn grains with an average size of 640 nm exhibit strong basal texture,detected by transmission electron back-scatter diffraction.Li distribution is determined by three-dimensional atom probe,which reveals the formation of nano-sized metastableα-Li2Zn3 precipitates with a number density of 7.16×10^22 m^-3.The fine lamellar Zn+β-LiZn4 structure,sub-micron grains and the nano-sized precipitates contribute to the superior mechanical properties.
