Zinc and Zn-Ni alloy compositionally modulated multilayer （CMM） coatings were electrodeposited on to a steel substrate by the successive deposition of zinc and Zn-Ni alloy sublayers from dual baths. The coated sampl...Zinc and Zn-Ni alloy compositionally modulated multilayer （CMM） coatings were electrodeposited on to a steel substrate by the successive deposition of zinc and Zn-Ni alloy sublayers from dual baths. The coated samples were evaluated in terms of the surface appearance, surface and cross-sectional morphologies, as well as corrosion resistance. The microstructural characteristics that were examined using the field emission gun scanning electron microscopy （FEGSEM） confirmed the layered structure, grain refinement of the zinc and Zn-Ni alloy CMM coatings, and revealed the existence of microcracks caused by the internal stress in the thick Zn-Ni alloy sublayers. The corrosion resistance that was evaluated by means of the salt spray test shows that the zinc and Zn-Ni alloy CMM coatings were more corrosion-resistant than the monolithic coatings of zinc or Zn-Ni alloy of the same thickness. The possible reasons for the better protective performance of Zn-Ni/Zn CMM coatings were given on the basis of the analysis on the micrographic features of zinc and Zn-Ni alloy CMM eoatings after the corrosion test. A probable corrosion mechanism of zinc and Zn-Ni alloy CMM coatings was also proposed.展开更多
Zinc and Zn-Ni alloy compositionally modulated multilayer （CMM） coatings were electrodeposited from dual baths. The coated samples were evaluated in terms of surface appearance, surface and cross-sectional morpholog...Zinc and Zn-Ni alloy compositionally modulated multilayer （CMM） coatings were electrodeposited from dual baths. The coated samples were evaluated in terms of surface appearance, surface and cross-sectional morphologies, as well as corrosion resistance. The results obtained from the salt spray test show that the zinc and Zn-Ni alloy CMM coatings are more corrosion-resistant than the monolithic coatings of zinc or Zn-Ni alloy alone with a similar thickness. The corrosion potential measurement and anodic polarisation tests were undertaken to examine the probable corrosion mechanisms of zinc and Zn-Ni alloy CMM coatings. Analysis on the micrographic features of zinc and Zn-Ni alloy CMM coatings after the corrosion test explains the probable reasons why the Zn-Ni/Zn CMM coatings have a better protective performance. Surface morphologies and compositional analysis of the remaining coating material of Zn-Ni alloy deposit after the corrosion test confirms the dezincification mechanism of the Zn-Ni alloy deposit during the corrosion process.展开更多
The effect of particle deformation zone(PDZ) on the microstructure and mechanical properties of SiC_(p)/Mg-5Zn composites was studied.Meanwhile,the work hardening and so ftening behavior of SiC_(p)/Mg-5Zn composites i...The effect of particle deformation zone(PDZ) on the microstructure and mechanical properties of SiC_(p)/Mg-5Zn composites was studied.Meanwhile,the work hardening and so ftening behavior of SiC_(p)/Mg-5Zn composites influenced by PDZ size were analyzed and discussed using neutron diffraction under in-situ tensile deformation.The evolution of FWHM(full width at half maximum) extracted from the diffraction pattern of SiC_(p)/Mg-5Zn composites was used to interpret the modification of dislocation density during in-situ tension,which discovered the effect of dislocation on the work hardening behavior of SiC_(p)/Mg-5Zn composites.In addition,the tensile stress reduction(△P_i) values during in-situ tension test were calculated to analyze the effect of PDZ size on the softening behavior of SiC_(p)/Mg-5Zn composites.The results show that the work hardening rate of SiC_(p)/Mg-5Zn composites increased with the enlargement of PDZ size,which was attributed to the grain size of SiC_(p)/Mg-5Zn composites increased with the enlargement of PDZ size.Moreover,the stress reduction(△P_i) values increased continuously during in-situ tensile for SiC_(p)/Mg-5Zn composites due to the increased stored energy produced during plastic deformation,which provided a driving force for the softening effect.However,the effect of grain size on the softening behavior is greater than that of the stored energy,which led to the tensile stress reduction(△P_i) values of P30(d_(PDZ)=30 μm)-SiC_(p)/Mg-5Zn composite were higher than that of P60(d_(PDZ)=60 μm)-SiC_(p)/Mg-5Zn composite when the ε_(ri) were 0.25,0.5,0.75 and 1,respectively.展开更多
The co-continuous(HA+β-TCP)/Zn−3Sn composite was fabricated via vacuum casting-infiltration method.The microstructure,mechanical properties,corrosion behaviors,and hemolysis ratio of the composite were studied by sca...The co-continuous(HA+β-TCP)/Zn−3Sn composite was fabricated via vacuum casting-infiltration method.The microstructure,mechanical properties,corrosion behaviors,and hemolysis ratio of the composite were studied by scanning electron microscope,X-ray diffractometer,mechanical testing,electrochemical test,immersion test,and ultraviolet spectrophotometry.The results indicate that Zn−3Sn alloy infiltrated into porous HA+β-TCP scaffold,which resulted in the formation of a compact(HA+β-TCP)/Zn−3Sn co-continuous composite,without any reaction layer between the Zn−3Sn alloy and the HA+β-TCP scaffold.The compressive strength of the composite was equal to about 3/4 that of Zn−3Sn alloy bulk.The corrosion rate of composite in simulated body fluid solution was slightly higher than that of Zn−3Sn alloy bulk.The main corrosion product on the composite surface was Zn(OH)2.The hemolysis rate of the composite was lower than that of Zn–3Sn alloy bulk and exhibited superior blood compatibility.展开更多
The micromechanical behaviour of Al2O3 short fibre reinforced Al-5.5Zn matrix composite has been in-situ studied by using TEM. The results show that in the composite the nucleation and propagation of cracks take place...The micromechanical behaviour of Al2O3 short fibre reinforced Al-5.5Zn matrix composite has been in-situ studied by using TEM. The results show that in the composite the nucleation and propagation of cracks take place mainly in the matrix, as well as in the region near the fibre/matrix interface. It has been also observed that the microcracks can close during unloading.So the fracture property can be characterized by crack open displacement (COD). The cracking characteristic may result from the large strength difference between the matrix and fibre.展开更多
Zinc(Zn)-based composites are promising biodegradable bone-implant materials because of their good biocompatibility,processability,and biodegradability.Nevertheless,the low interfacial bonding strength,co-ordinated de...Zinc(Zn)-based composites are promising biodegradable bone-implant materials because of their good biocompatibility,processability,and biodegradability.Nevertheless,the low interfacial bonding strength,co-ordinated deformation capacity,and mechanical strength of current Zn-based composites hinder their clinical application.In this study,we developed a biodegradable in situ 4Mg_(2)Ge/Zn-0.3Cu-0.05P composite(denoted ZMGCP)via phosphorus(P)modification and hot-rolling for bone-implant applications.The mechanical prop-erties,corrosion behavior,biotribological performance,in vitro cytocompatibility and osteogenic differentiation,and in vivo osteogenesis and osteointegration of the as-cast(AC)and hot-rolled(HR)ZMGCP samples were systematically evaluated and compared to those of 4Mg_(2)Ge/Zn-0.3Cu(denoted ZMGC).The primary and eutectic reinforcement Mg_(2)Ge phases formed during solidification were refined after P modification and hot-rolling.The HR ZMGCP exhibited the best tensile properties among all the samples with an ultimate tensile strength of 288.9 MPa,a yield strength of 194.5 MPa,and an elongation of 17.7%.The HR ZMGCP showed the lowest corrosion rate of 336μm/a,186μm/a,and 61.7μm/a as measured by potentiodynamic polarization,electrochemical impedance spectroscopy,and immersion testing,respectively,among all the samples in Hanks’solution.The HR ZMGCP also showed higher biotribological resistance than its ZMGC counterpart.The HR ZMGCP exhibited the highest in vitro cytocompatibility,the best osteogenesis capability and angiogenesis property among the HR samples of pure Zn,ZMGC,and ZMGCP.Furthermore,the HR ZMGCP displayed complete in vivo biocompati-bility,osteogenesis,osteointegration capability,and an appropriate degradation rate,showing significant po-tential for a biodegradable bone-implant material.展开更多
Pyrex glasses with different ZnS: Mn^(2+) contents were prepared by melting method. It has been found that Mn ion may occupy two sites: (Mn^(2+) )sub and (Mn^(2+) )int from photoluminescene (PL) and photoluminescence ...Pyrex glasses with different ZnS: Mn^(2+) contents were prepared by melting method. It has been found that Mn ion may occupy two sites: (Mn^(2+) )sub and (Mn^(2+) )int from photoluminescene (PL) and photoluminescence excitation (PLE) spectra. The results were confirmed by the further electron paramagnetic resonance (EPR) experiments and the three types of states (Mn^(2+) )sub, (Mn^(2+) )int and Mn clusters were identified. It was observed that the g-factor and the hyperfine structure (HFS) constant increase with the decreasing size of nanocrystallite. This may result from hybridization of sp3 electron states of ZnS and 3d5 electron states of Mn by the effects of quantum confinement and the surface states.展开更多
结合了三维结构和亲锌物种的集流体构筑策略被认为是构建高稳定锌金属负极的有效方法.然而,高昂的成本和复杂的制备工艺阻碍了其实际应用.本文通过在有均匀Cu^(2+)锚定的碳布集流体(ACC-600@Cu^(2+))上沉积锌,合理设计了一种稳定的三维...结合了三维结构和亲锌物种的集流体构筑策略被认为是构建高稳定锌金属负极的有效方法.然而,高昂的成本和复杂的制备工艺阻碍了其实际应用.本文通过在有均匀Cu^(2+)锚定的碳布集流体(ACC-600@Cu^(2+))上沉积锌,合理设计了一种稳定的三维锌金属复合阳极(Zn@ACC-600@Cu^(2+)).在锌成核过程中,Cu^(2+)原位还原为金属Cu,然后随着锌的进一步沉积,碳布表面逐渐形成均匀的亲锌的Cu-Zn合金界面层.密度泛函理论计算和实验观察表明,Cu-Zn合金界面不仅可以作为锌离子的亲锌沉积点,而且可以提高导电率,使电场和锌离子通量均匀化.因此,ACC-600@Cu^(2+)集流体可以实现高的镀锌/剥离可逆性,并在15.8 mV的极化电压下稳定循环410 h以上.作为概念验证,我们组装的Zn@ACC-600@Cu^(2+)‖MnO_(2)全电池具有良好的电池倍率性能,与原始碳布相比,其比容量显著提高至110 mA h g^(-1).本文提出的原位还原策略为三维锌金属复合负极的设计提供了一种简便且低成本的方法,促进了无枝晶和高稳定锌金属电池的发展.展开更多
文摘Zinc and Zn-Ni alloy compositionally modulated multilayer （CMM） coatings were electrodeposited on to a steel substrate by the successive deposition of zinc and Zn-Ni alloy sublayers from dual baths. The coated samples were evaluated in terms of the surface appearance, surface and cross-sectional morphologies, as well as corrosion resistance. The microstructural characteristics that were examined using the field emission gun scanning electron microscopy （FEGSEM） confirmed the layered structure, grain refinement of the zinc and Zn-Ni alloy CMM coatings, and revealed the existence of microcracks caused by the internal stress in the thick Zn-Ni alloy sublayers. The corrosion resistance that was evaluated by means of the salt spray test shows that the zinc and Zn-Ni alloy CMM coatings were more corrosion-resistant than the monolithic coatings of zinc or Zn-Ni alloy of the same thickness. The possible reasons for the better protective performance of Zn-Ni/Zn CMM coatings were given on the basis of the analysis on the micrographic features of zinc and Zn-Ni alloy CMM eoatings after the corrosion test. A probable corrosion mechanism of zinc and Zn-Ni alloy CMM coatings was also proposed.
文摘Zinc and Zn-Ni alloy compositionally modulated multilayer （CMM） coatings were electrodeposited from dual baths. The coated samples were evaluated in terms of surface appearance, surface and cross-sectional morphologies, as well as corrosion resistance. The results obtained from the salt spray test show that the zinc and Zn-Ni alloy CMM coatings are more corrosion-resistant than the monolithic coatings of zinc or Zn-Ni alloy alone with a similar thickness. The corrosion potential measurement and anodic polarisation tests were undertaken to examine the probable corrosion mechanisms of zinc and Zn-Ni alloy CMM coatings. Analysis on the micrographic features of zinc and Zn-Ni alloy CMM coatings after the corrosion test explains the probable reasons why the Zn-Ni/Zn CMM coatings have a better protective performance. Surface morphologies and compositional analysis of the remaining coating material of Zn-Ni alloy deposit after the corrosion test confirms the dezincification mechanism of the Zn-Ni alloy deposit during the corrosion process.
基金supported financially by the National Natural Science Foundation of China(Nos.51771128 and 51771129)the Shanxi Province Science and Technology Major Projects(No.20181101008)the Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi。
文摘The effect of particle deformation zone(PDZ) on the microstructure and mechanical properties of SiC_(p)/Mg-5Zn composites was studied.Meanwhile,the work hardening and so ftening behavior of SiC_(p)/Mg-5Zn composites influenced by PDZ size were analyzed and discussed using neutron diffraction under in-situ tensile deformation.The evolution of FWHM(full width at half maximum) extracted from the diffraction pattern of SiC_(p)/Mg-5Zn composites was used to interpret the modification of dislocation density during in-situ tension,which discovered the effect of dislocation on the work hardening behavior of SiC_(p)/Mg-5Zn composites.In addition,the tensile stress reduction(△P_i) values during in-situ tension test were calculated to analyze the effect of PDZ size on the softening behavior of SiC_(p)/Mg-5Zn composites.The results show that the work hardening rate of SiC_(p)/Mg-5Zn composites increased with the enlargement of PDZ size,which was attributed to the grain size of SiC_(p)/Mg-5Zn composites increased with the enlargement of PDZ size.Moreover,the stress reduction(△P_i) values increased continuously during in-situ tensile for SiC_(p)/Mg-5Zn composites due to the increased stored energy produced during plastic deformation,which provided a driving force for the softening effect.However,the effect of grain size on the softening behavior is greater than that of the stored energy,which led to the tensile stress reduction(△P_i) values of P30(d_(PDZ)=30 μm)-SiC_(p)/Mg-5Zn composite were higher than that of P60(d_(PDZ)=60 μm)-SiC_(p)/Mg-5Zn composite when the ε_(ri) were 0.25,0.5,0.75 and 1,respectively.
基金the National Natural Science Foundation of China(No.51101039)the Fundamental Research Funds for the Central Universities,China(No.3072020CFT0702).
文摘The co-continuous(HA+β-TCP)/Zn−3Sn composite was fabricated via vacuum casting-infiltration method.The microstructure,mechanical properties,corrosion behaviors,and hemolysis ratio of the composite were studied by scanning electron microscope,X-ray diffractometer,mechanical testing,electrochemical test,immersion test,and ultraviolet spectrophotometry.The results indicate that Zn−3Sn alloy infiltrated into porous HA+β-TCP scaffold,which resulted in the formation of a compact(HA+β-TCP)/Zn−3Sn co-continuous composite,without any reaction layer between the Zn−3Sn alloy and the HA+β-TCP scaffold.The compressive strength of the composite was equal to about 3/4 that of Zn−3Sn alloy bulk.The corrosion rate of composite in simulated body fluid solution was slightly higher than that of Zn−3Sn alloy bulk.The main corrosion product on the composite surface was Zn(OH)2.The hemolysis rate of the composite was lower than that of Zn–3Sn alloy bulk and exhibited superior blood compatibility.
文摘The micromechanical behaviour of Al2O3 short fibre reinforced Al-5.5Zn matrix composite has been in-situ studied by using TEM. The results show that in the composite the nucleation and propagation of cracks take place mainly in the matrix, as well as in the region near the fibre/matrix interface. It has been also observed that the microcracks can close during unloading.So the fracture property can be characterized by crack open displacement (COD). The cracking characteristic may result from the large strength difference between the matrix and fibre.
基金supported by the Zhejiang Public Welfare Technology Application Research Project of China(No.LTGY24H140002,No.LTGY23H140002,No.LGF22H140008)financial support for this research by the Australian Research Council(ARC)through the Discovery Project DP240101131.
文摘Zinc(Zn)-based composites are promising biodegradable bone-implant materials because of their good biocompatibility,processability,and biodegradability.Nevertheless,the low interfacial bonding strength,co-ordinated deformation capacity,and mechanical strength of current Zn-based composites hinder their clinical application.In this study,we developed a biodegradable in situ 4Mg_(2)Ge/Zn-0.3Cu-0.05P composite(denoted ZMGCP)via phosphorus(P)modification and hot-rolling for bone-implant applications.The mechanical prop-erties,corrosion behavior,biotribological performance,in vitro cytocompatibility and osteogenic differentiation,and in vivo osteogenesis and osteointegration of the as-cast(AC)and hot-rolled(HR)ZMGCP samples were systematically evaluated and compared to those of 4Mg_(2)Ge/Zn-0.3Cu(denoted ZMGC).The primary and eutectic reinforcement Mg_(2)Ge phases formed during solidification were refined after P modification and hot-rolling.The HR ZMGCP exhibited the best tensile properties among all the samples with an ultimate tensile strength of 288.9 MPa,a yield strength of 194.5 MPa,and an elongation of 17.7%.The HR ZMGCP showed the lowest corrosion rate of 336μm/a,186μm/a,and 61.7μm/a as measured by potentiodynamic polarization,electrochemical impedance spectroscopy,and immersion testing,respectively,among all the samples in Hanks’solution.The HR ZMGCP also showed higher biotribological resistance than its ZMGC counterpart.The HR ZMGCP exhibited the highest in vitro cytocompatibility,the best osteogenesis capability and angiogenesis property among the HR samples of pure Zn,ZMGC,and ZMGCP.Furthermore,the HR ZMGCP displayed complete in vivo biocompati-bility,osteogenesis,osteointegration capability,and an appropriate degradation rate,showing significant po-tential for a biodegradable bone-implant material.
基金Project supported by the National Natural Science Foundation of ChinaLaboratory of Excited State Processes, Chinese Academy of Sciences
文摘Pyrex glasses with different ZnS: Mn^(2+) contents were prepared by melting method. It has been found that Mn ion may occupy two sites: (Mn^(2+) )sub and (Mn^(2+) )int from photoluminescene (PL) and photoluminescence excitation (PLE) spectra. The results were confirmed by the further electron paramagnetic resonance (EPR) experiments and the three types of states (Mn^(2+) )sub, (Mn^(2+) )int and Mn clusters were identified. It was observed that the g-factor and the hyperfine structure (HFS) constant increase with the decreasing size of nanocrystallite. This may result from hybridization of sp3 electron states of ZnS and 3d5 electron states of Mn by the effects of quantum confinement and the surface states.
基金supported by the National Natural Science Foundation of China(22001236)the Program for Innovative Research Team(in Science and Technology)in Universities of Henan Province(19IRTSTHN022)Zhengzhou University。
文摘结合了三维结构和亲锌物种的集流体构筑策略被认为是构建高稳定锌金属负极的有效方法.然而,高昂的成本和复杂的制备工艺阻碍了其实际应用.本文通过在有均匀Cu^(2+)锚定的碳布集流体(ACC-600@Cu^(2+))上沉积锌,合理设计了一种稳定的三维锌金属复合阳极(Zn@ACC-600@Cu^(2+)).在锌成核过程中,Cu^(2+)原位还原为金属Cu,然后随着锌的进一步沉积,碳布表面逐渐形成均匀的亲锌的Cu-Zn合金界面层.密度泛函理论计算和实验观察表明,Cu-Zn合金界面不仅可以作为锌离子的亲锌沉积点,而且可以提高导电率,使电场和锌离子通量均匀化.因此,ACC-600@Cu^(2+)集流体可以实现高的镀锌/剥离可逆性,并在15.8 mV的极化电压下稳定循环410 h以上.作为概念验证,我们组装的Zn@ACC-600@Cu^(2+)‖MnO_(2)全电池具有良好的电池倍率性能,与原始碳布相比,其比容量显著提高至110 mA h g^(-1).本文提出的原位还原策略为三维锌金属复合负极的设计提供了一种简便且低成本的方法,促进了无枝晶和高稳定锌金属电池的发展.
