The corrosion resistance of Zr-1Nb alloy was compared with that of Zr-Sn-Nb-Fe and Zr-4 alloys, and the effect of hydrochemistry on the corrosion resistance of Zr-1Nb alloy was discussed. Experimental results show tha...The corrosion resistance of Zr-1Nb alloy was compared with that of Zr-Sn-Nb-Fe and Zr-4 alloys, and the effect of hydrochemistry on the corrosion resistance of Zr-1Nb alloy was discussed. Experimental results show that niobium oxide is partly soluble in LiOH aqueous solution. Therefore, when Zr-1Nb alloy is corroded in LiOH aqueous solution, a soluble niobate produced by the reaction between the corrosion products of beta -Nb particles and LiOH results in the formation of pores in the zirconium oxide films and causes the degradation of the corrosion resistance of Zr-1Nb alloy tested in LiOH aqueous solution.展开更多
The haemocompatibility of Ti-3Zr-2Sn-3Mo-25Nb biomedical alloy was studied after surface heparinization. A layer of sol-gel TiO2 films was applied on the alloy samples followed by active treatment in the bio-functiona...The haemocompatibility of Ti-3Zr-2Sn-3Mo-25Nb biomedical alloy was studied after surface heparinization. A layer of sol-gel TiO2 films was applied on the alloy samples followed by active treatment in the bio-functionalized solution for introducing the OH- and groups, and then the heparin was immobilized on the active TiO2 films through the electrostatic self assembly technology. It is shown that the heparinized films are mainly composed of anatase and rutile with smooth and dense surface. In vitro blood compatibility was evaluated by haemolysis test, clotting time and platelet adhesion behavior tests. The results show that the haemocompatibility of the alloy could be significantly improved by surface heparinization.展开更多
A layer of porous film containing Ca and P was prepared by the micro-arc oxidation method on the surface of a novel near β biomedical Ti-3Zr-2Sn-3Mo-25Nb alloy, and then NH2- active group was introduced to the films ...A layer of porous film containing Ca and P was prepared by the micro-arc oxidation method on the surface of a novel near β biomedical Ti-3Zr-2Sn-3Mo-25Nb alloy, and then NH2- active group was introduced to the films by activation treatment. The phase composition, surface micro-topography and elemental characteristics of the micro-arc oxidation films were investigated with XRD, SEM, EDS and XPS, and the osteoinduction of the micro-arc oxidation films was tested using the simulated body fluid immersion, the in-vitro osteoblast cultivation test and animal experiment. The results show that the oxide layer is a kind of porous ceramic intermixture and contains Ca and P. The films in the simulated body fluid can induce apatite formation, resulting in excellent bioactivity. The cell test discovers that osteoblasts can grow well on the surface of micro-arc oxidation films. And the Ti-3Zr-2Sn-3Mo-25Nb biomedical alloy coated with active porous calcium-phosphate films shows better osteoinduction in vivo.展开更多
The dynamic recrystallization（DRX） behavior of Ti-6Al-2Zr-1Mo-1V alloy was investigated at deformation temperature of 1000-1100 °C and strain rate of 10-3-1.0 s-1 by using compression test.The results show that...The dynamic recrystallization（DRX） behavior of Ti-6Al-2Zr-1Mo-1V alloy was investigated at deformation temperature of 1000-1100 °C and strain rate of 10-3-1.0 s-1 by using compression test.The results show that discontinuous dynamic recrystallization（DDRX） is the predominant recrystallization mechanism at temperature higher than 1050 °C and strain rate lower than 0.01 s-1.Meanwhile,continuous dynamic recrystallization is the main mechanism observed at temperature below 1050 °C and strain rate above 0.01 s-1,mixed with a few DDRX grains.In addition,decreasing strain rate and increasing deformation temperature are found to facilitate the progress of DRX and refinement of grains in the Ti alloy in β forging process.展开更多
The isothermal compression tests were carried out in the Thermecmastor-Z thermo-simulator at temperatures of 800, 850, 900, 950, 1000 and 1050 ℃ and the strain rates of 0.01, 0.1, 1 and 10 s-1. The influence of defor...The isothermal compression tests were carried out in the Thermecmastor-Z thermo-simulator at temperatures of 800, 850, 900, 950, 1000 and 1050 ℃ and the strain rates of 0.01, 0.1, 1 and 10 s-1. The influence of deformation temperature and strain rate on the flow stress of Ti-6Al-2Zr-IMo-IV alloy was studied. Based on the experimental data sets, the high temperature deformation behavior of Ti-6A1-2Zr-IMo-IV alloy was presented using the intelligent method of artificial neural network （ANN）. The results indicate that the predicted flow stress values by ANN model is quite consistent with the experimental results, which implies that the artificial neural network is an effective tool for studying the hot deformation behavior of the present alloy. In addition, the development of graphical user interface is implemented using Visual Basic programming language.展开更多
The true stress-strain curves of Ti-6Al-2Zr-1Mo-1V alloy were achieved by a series of isothermal compression tests with height reduction of 60% under the deformation temperatures of 1073-1323 K and the strain rates of...The true stress-strain curves of Ti-6Al-2Zr-1Mo-1V alloy were achieved by a series of isothermal compression tests with height reduction of 60% under the deformation temperatures of 1073-1323 K and the strain rates of 0.01-10s 1.The critical conditions for the onset of DRX were attained when the value of d /d,where strain hardening rate d /d,reached the minimum which corresponds to an inflection of θ versus σ curve.Thus,two important potential parameters,critical strain and critical stress,were identified,and expressed as εc/εp=0.37-0.60,σc/σp=0.81-0.91.Furthermore,by the regression analysis for conventional hyperbolic sine equation,the main material parameters such as α,β,n,and DRX activation energy,Q,were calculated.In addition,the evolution of Q with strain rate and temperature was revealed as a 3D response surface.展开更多
The initiation sites and influencing factors of cavity nucleation were investigated for a Ti-6Al-2Zr-1Mo-1V alloy with lamellar starting structure,using the isothermal hot compression test.All samples were deformed to...The initiation sites and influencing factors of cavity nucleation were investigated for a Ti-6Al-2Zr-1Mo-1V alloy with lamellar starting structure,using the isothermal hot compression test.All samples were deformed to a true strain of 0.70 in the temperature range of 750-950°C and strain rate range of 0.001-10 s-1.The corresponding microstructures were observed by means of the metallurgical microscopy and scanning electron microscopy(SEM).It was found that all cavities occurred at the bulge regions of the compression specimens.Most of cavities nucleated along prior beta boundaries oriented 45°to the compression axis,while others nucleated at the interfaces of lamellar alpha colonies.Cavity nucleation was inhibited with increasing the volume fraction of beta phase and the volume fraction spheroidized of lamellar alpha phase.展开更多
文摘The corrosion resistance of Zr-1Nb alloy was compared with that of Zr-Sn-Nb-Fe and Zr-4 alloys, and the effect of hydrochemistry on the corrosion resistance of Zr-1Nb alloy was discussed. Experimental results show that niobium oxide is partly soluble in LiOH aqueous solution. Therefore, when Zr-1Nb alloy is corroded in LiOH aqueous solution, a soluble niobate produced by the reaction between the corrosion products of beta -Nb particles and LiOH results in the formation of pores in the zirconium oxide films and causes the degradation of the corrosion resistance of Zr-1Nb alloy tested in LiOH aqueous solution.
基金Project (31100693/C100302) supported by the National Natural Science Foundation of ChinaProject (31011120049) supported by the Australia-China Special Fund, International Science Linkages Program co-supported by the Department of Innovation, Industry, Science and Research of Australia, and the Ministry of Science and Technology and National Science Foundation of China+1 种基金Project(2010ZDKG-96) supported by the Major Subject of "13115" Programs of Shaan’xi Province, ChinaProject (2012CB619102) supported by the National Basic Research Program of China
文摘The haemocompatibility of Ti-3Zr-2Sn-3Mo-25Nb biomedical alloy was studied after surface heparinization. A layer of sol-gel TiO2 films was applied on the alloy samples followed by active treatment in the bio-functionalized solution for introducing the OH- and groups, and then the heparin was immobilized on the active TiO2 films through the electrostatic self assembly technology. It is shown that the heparinized films are mainly composed of anatase and rutile with smooth and dense surface. In vitro blood compatibility was evaluated by haemolysis test, clotting time and platelet adhesion behavior tests. The results show that the haemocompatibility of the alloy could be significantly improved by surface heparinization.
基金Project (2005CB623904) supported by the National Basic Research Program of ChinaProject (30770586) supported by the National Natural Science Foundation of China+1 种基金Project (31011120049) supported by the Australia-China special fund, International Science Linkages Program co-supported by the Department of Innovation, Industry, Science and Research of Australia, and the Ministry of Science and Technology and National Science Foundation of ChinaProject (2010ZDKG-96) supported by the major Subject of "13115" Programs of Shaan’xi Province, China
文摘A layer of porous film containing Ca and P was prepared by the micro-arc oxidation method on the surface of a novel near β biomedical Ti-3Zr-2Sn-3Mo-25Nb alloy, and then NH2- active group was introduced to the films by activation treatment. The phase composition, surface micro-topography and elemental characteristics of the micro-arc oxidation films were investigated with XRD, SEM, EDS and XPS, and the osteoinduction of the micro-arc oxidation films was tested using the simulated body fluid immersion, the in-vitro osteoblast cultivation test and animal experiment. The results show that the oxide layer is a kind of porous ceramic intermixture and contains Ca and P. The films in the simulated body fluid can induce apatite formation, resulting in excellent bioactivity. The cell test discovers that osteoblasts can grow well on the surface of micro-arc oxidation films. And the Ti-3Zr-2Sn-3Mo-25Nb biomedical alloy coated with active porous calcium-phosphate films shows better osteoinduction in vivo.
基金Project (2007CB613803) supported by the National Basic Research Program of ChinaProject (2010GQC0170) supported by the Natural Science Foundation of Jiangxi Province,ChinaProject (GJJ11159) supported by the Educational Committee of Jiangxi Province,China
文摘The dynamic recrystallization（DRX） behavior of Ti-6Al-2Zr-1Mo-1V alloy was investigated at deformation temperature of 1000-1100 °C and strain rate of 10-3-1.0 s-1 by using compression test.The results show that discontinuous dynamic recrystallization（DDRX） is the predominant recrystallization mechanism at temperature higher than 1050 °C and strain rate lower than 0.01 s-1.Meanwhile,continuous dynamic recrystallization is the main mechanism observed at temperature below 1050 °C and strain rate above 0.01 s-1,mixed with a few DDRX grains.In addition,decreasing strain rate and increasing deformation temperature are found to facilitate the progress of DRX and refinement of grains in the Ti alloy in β forging process.
基金Project (2007CB613807) supported by the National Basic Research Program of ChinaProject (35-TP-2009) supported by the Fund of the State Key Laboratory of Solidification Processing in NWPU,ChinaProject (51075333) supported by the National Natural Science Foundation of China
文摘The isothermal compression tests were carried out in the Thermecmastor-Z thermo-simulator at temperatures of 800, 850, 900, 950, 1000 and 1050 ℃ and the strain rates of 0.01, 0.1, 1 and 10 s-1. The influence of deformation temperature and strain rate on the flow stress of Ti-6Al-2Zr-IMo-IV alloy was studied. Based on the experimental data sets, the high temperature deformation behavior of Ti-6A1-2Zr-IMo-IV alloy was presented using the intelligent method of artificial neural network （ANN）. The results indicate that the predicted flow stress values by ANN model is quite consistent with the experimental results, which implies that the artificial neural network is an effective tool for studying the hot deformation behavior of the present alloy. In addition, the development of graphical user interface is implemented using Visual Basic programming language.
基金Project(2012ZX04010081)supported by the National Key Technologies R&D Program of ChinaProject(cstc2009aa3012-1)supported by the Science and Technology Committee of Chongqing,ChinaProject(CDJZR12130045)supported by the Fundamental Research Funds for the Central Universities,China
文摘The true stress-strain curves of Ti-6Al-2Zr-1Mo-1V alloy were achieved by a series of isothermal compression tests with height reduction of 60% under the deformation temperatures of 1073-1323 K and the strain rates of 0.01-10s 1.The critical conditions for the onset of DRX were attained when the value of d /d,where strain hardening rate d /d,reached the minimum which corresponds to an inflection of θ versus σ curve.Thus,two important potential parameters,critical strain and critical stress,were identified,and expressed as εc/εp=0.37-0.60,σc/σp=0.81-0.91.Furthermore,by the regression analysis for conventional hyperbolic sine equation,the main material parameters such as α,β,n,and DRX activation energy,Q,were calculated.In addition,the evolution of Q with strain rate and temperature was revealed as a 3D response surface.
基金Project(2009ZE56014)supported by the Aeronautical Science Foundation of ChinaProject(gf200901008)supported by the Open Fund of National Defense Key Disciplines Laboratory of Light Alloy Processing Science and Technology,Nanchang Hangkong University,China
文摘The initiation sites and influencing factors of cavity nucleation were investigated for a Ti-6Al-2Zr-1Mo-1V alloy with lamellar starting structure,using the isothermal hot compression test.All samples were deformed to a true strain of 0.70 in the temperature range of 750-950°C and strain rate range of 0.001-10 s-1.The corresponding microstructures were observed by means of the metallurgical microscopy and scanning electron microscopy(SEM).It was found that all cavities occurred at the bulge regions of the compression specimens.Most of cavities nucleated along prior beta boundaries oriented 45°to the compression axis,while others nucleated at the interfaces of lamellar alpha colonies.Cavity nucleation was inhibited with increasing the volume fraction of beta phase and the volume fraction spheroidized of lamellar alpha phase.
