Titanium(Ti)and its alloys have been widely used as orthopedic implants,because of their favorable mechanical properties,corrosion resistance and biocompatibility.Despite their significant success in various clinical ...Titanium(Ti)and its alloys have been widely used as orthopedic implants,because of their favorable mechanical properties,corrosion resistance and biocompatibility.Despite their significant success in various clinical applications,the probability of failure,degradation and revision is undesirably high,especially for the patients with low bone density,insufficient quantity of bone or osteoporosis,which renders the studies on surface modification of Ti still active to further improve clinical results.It is discerned that surface physicochemical properties directly influence and even control the dynamic interaction that subsequently determines the success or rejection of orthopedic implants.Therefore,it is crucial to endow bulk materials with specific surface properties of high bioactivity that can be performed by surface modification to realize the osseointegration.This article first reviews surface characteristics of Ti materials and various conventional surface modification techniques involving mechanical,physical and chemical treatments based on the formation mechanism of the modified coatings.Such conventional methods are able to improve bioactivity of Ti implants,but the surfaces with static state cannot respond to the dynamic biological cascades from the living cells and tissues.Hence,beyond traditional static design,dynamic responsive avenues are then emerging.The dynamic stimuli sources for surface functionalization can originate from environmental triggers or physiological triggers.In short,this review surveys recent developments in the surface engineering of Ti materials,with a specific emphasis on advances in static to dynamic functionality,which provides perspectives for improving bioactivity and biocompatibility of Ti implants.展开更多
Porous titanium fiber materials with the fiber sizes of 70--120 μm in diameter were prepared by vacuum sintering technology. The morphology and compressive properties of porous titanium fiber materials were investiga...Porous titanium fiber materials with the fiber sizes of 70--120 μm in diameter were prepared by vacuum sintering technology. The morphology and compressive properties of porous titanium fiber materials were investigated by using a scanning electron microscope （SEM） and an MST 858 compression testing machine in quasi-static condition. The results show that porous titanium fibers form complex micro-networks. The stress-strain curves of por- ous titanium fiber materials exhibit elastic region, platform region and densification region and no collapse during platform region. The yield strength of porous titanium fiber materials decreases with increasing the porosity and increasing the fiber diameter.展开更多
The porous titanium fiber materials with open porosity were successfully prepared by the vacuum sintering technology. The morphology characteristics of sintering neck of porous titanium fiber materials were investigat...The porous titanium fiber materials with open porosity were successfully prepared by the vacuum sintering technology. The morphology characteristics of sintering neck of porous titanium fiber materials were investigated by scanning electron microscopy （SEM）. The results show that the formation and growth of sintering neck of porous ti- tanium fiber material approximately follow the rule that the primary mechanism is grain boundary diffusion and sub- sidiary mechanisms are other diffusion mechanisms during the sintering process. The formation and growth of the sintering neck depend mainly on the sintering temperature and slightly on the soaking time. The sintering system of porous titanium fiber material was determined and the equation of the sintering neck＇s length was established.展开更多
The high-temperature acoustic absorption performance of porous titanium fiber material was investigated in terms of sample thickness, porosity, temperature, air-cavity thickness and double-layer structure arrangement....The high-temperature acoustic absorption performance of porous titanium fiber material was investigated in terms of sample thickness, porosity, temperature, air-cavity thickness and double-layer structure arrangement. The effects on absorption coefficient were systematically assessed. The results show that the sound absorption performance is improved by increasing the sample porosity and/or thickness, and/or increasing the air-cavity thickness. Meanwhile, increasing the temperature gives better acoustic absorption performance in the low frequency range but also lowers the performance in the high frequency range, while double-layer structure enables better acoustic absorption performance.展开更多
Titanium metal and alloy are key materials for technological development,which significantly promote the development of the hightech economy in China.The consumption of high-end titanium materials and the developmenta...Titanium metal and alloy are key materials for technological development,which significantly promote the development of the hightech economy in China.The consumption of high-end titanium materials and the developmental level of the titanium industry are important indexes of a country’s comprehensive power.However,at present,the application amount and level of high-end titanium materials in China are limited by many factors,including the dependence of raw materials on imports,high processing cost,and structural imbalance of products.Based on the characteristics of titanium resources and the current situation of the titanium industry,the whole titanium industrial chain in China should be updated.Improving the quality of raw materials is important to produce low-cost,high-end titanium materials using titanium resources with high calcium and magnesium contents in the Panxi region.In addition,the steel-titanium joint production is a vital step to reduce the processing cost of titanium materials.Moreover,the consumption structure of titanium materials should be completed to expand their application.Gradually implementing these suggestions,the overall level of China’s titanium industry will be greatly improved,thereby rapidly establishing an advanced scientific and technological country.展开更多
TiN/Al2O3 composite material was prepared by aluminothermic reduction of TiO2 in coke bed. The phase composition, lattice parameter and microstructure of products treated at 1 300 ℃ , 1 400 ℃, 1 500℃ for 3 h respec...TiN/Al2O3 composite material was prepared by aluminothermic reduction of TiO2 in coke bed. The phase composition, lattice parameter and microstructure of products treated at 1 300 ℃ , 1 400 ℃, 1 500℃ for 3 h respectively were analyzed by XRD, SEM and TEM. The results showed that TiN/Al2O3 composite material can be prepared in coke bed via aluminothermic reduction method. However, the treatment temperatures affect the evolution of aluminothermic reaction and morphology of the materials obviously. The content, grain size and lattice parameter of TiN in materials in coke bed increased with the increase of treatment temperature. Thermodynamic calculation confirmed that metal Al reacted with O2 in coke bed while it was involved in aluminothermic reduction reaction, causing the lack of Al and surplus rutile in the products.展开更多
This study investigates the feasibility of using electrochemical machining（ECM） to produce critical aeroengine components from a new burn-resistant titanium alloy（Ti40）, thereby reducing costs and improving effici...This study investigates the feasibility of using electrochemical machining（ECM） to produce critical aeroengine components from a new burn-resistant titanium alloy（Ti40）, thereby reducing costs and improving efficiency relative to conventional mechanical machining.Through this, it is found that an aqueous mix of sodium chloride and potassium bromide provides the optimal electrolyte and that the surface quality of the Ti40 workpiece is improved by using a pulsed current of1 k Hz rather than a direct current.Furthermore, the quality of cavities produced by ECM and the overall material removal rate are determined to be dependent on a combination of operating voltage, electrolyte inlet pressure, cathode feeding rate and electrolyte concentration.By optimizing these parameters, a surface roughness of 0.371 lm has been achieved in conjunction with a specific removal rate of more than 3.1 mm3/A？min.展开更多
Electron beam melting （EBM） has been used to manufacture β-type Ti-24Nb-4Zr-8Sn porous compo- nents with 70% porosity, EBM-produced components have favorable structural features （i.e. smooth strut surfaces, fewer ...Electron beam melting （EBM） has been used to manufacture β-type Ti-24Nb-4Zr-8Sn porous compo- nents with 70% porosity, EBM-produced components have favorable structural features （i.e. smooth strut surfaces, fewer defects） and an （α ＋ β）-type microstructure, similar to that subjected to aging treat- ment. EBM-produced components exhibit more than twice the strength-to-modulus ratio of porous Ti- 6A1-4V components having the same porosity. The processing-microstructure-property relationship and deformation behavior of EBM-produced components are discussed in detail. Such porous titanium com- ponents composed of non-toxic elements and having high strength-to-modulus ratio are highly attractive for biomedical applications.展开更多
On September 5,the journalist learned from the Shaanxi Province State-owned Assets Supervision and Administration Commission that,as the key R&D production base of Titanium alloy material for China’s air and spac...On September 5,the journalist learned from the Shaanxi Province State-owned Assets Supervision and Administration Commission that,as the key R&D production base of Titanium alloy material for China’s air and space industry,Shaanxi Nonferrous Baoti Group supplied 90%Titanium alloy material usage to China’s air and space industry,making it the main supplier of Titanium alloy for China’s new fighters and big planes.展开更多
基金supported by National Key Research and Development Program of China(grant Nos.2020YFC2004900,2016YFC1100300)the National Natural Science Foundation of China(grant Nos.21773199,51571169,52001265).
文摘Titanium(Ti)and its alloys have been widely used as orthopedic implants,because of their favorable mechanical properties,corrosion resistance and biocompatibility.Despite their significant success in various clinical applications,the probability of failure,degradation and revision is undesirably high,especially for the patients with low bone density,insufficient quantity of bone or osteoporosis,which renders the studies on surface modification of Ti still active to further improve clinical results.It is discerned that surface physicochemical properties directly influence and even control the dynamic interaction that subsequently determines the success or rejection of orthopedic implants.Therefore,it is crucial to endow bulk materials with specific surface properties of high bioactivity that can be performed by surface modification to realize the osseointegration.This article first reviews surface characteristics of Ti materials and various conventional surface modification techniques involving mechanical,physical and chemical treatments based on the formation mechanism of the modified coatings.Such conventional methods are able to improve bioactivity of Ti implants,but the surfaces with static state cannot respond to the dynamic biological cascades from the living cells and tissues.Hence,beyond traditional static design,dynamic responsive avenues are then emerging.The dynamic stimuli sources for surface functionalization can originate from environmental triggers or physiological triggers.In short,this review surveys recent developments in the surface engineering of Ti materials,with a specific emphasis on advances in static to dynamic functionality,which provides perspectives for improving bioactivity and biocompatibility of Ti implants.
基金Item Sponsored by National Natural Science Foundation of China(51304153)Natural Science Foundation of Shaanxi Province of China(2012JM6017)
文摘Porous titanium fiber materials with the fiber sizes of 70--120 μm in diameter were prepared by vacuum sintering technology. The morphology and compressive properties of porous titanium fiber materials were investigated by using a scanning electron microscope （SEM） and an MST 858 compression testing machine in quasi-static condition. The results show that porous titanium fibers form complex micro-networks. The stress-strain curves of por- ous titanium fiber materials exhibit elastic region, platform region and densification region and no collapse during platform region. The yield strength of porous titanium fiber materials decreases with increasing the porosity and increasing the fiber diameter.
基金Item Sponsored by National Natural Science Foundation of China(51304153)Natural Science Foundation of Shaanxi Province of China(2012JM6017)
文摘The porous titanium fiber materials with open porosity were successfully prepared by the vacuum sintering technology. The morphology characteristics of sintering neck of porous titanium fiber materials were investigated by scanning electron microscopy （SEM）. The results show that the formation and growth of sintering neck of porous ti- tanium fiber material approximately follow the rule that the primary mechanism is grain boundary diffusion and sub- sidiary mechanisms are other diffusion mechanisms during the sintering process. The formation and growth of the sintering neck depend mainly on the sintering temperature and slightly on the soaking time. The sintering system of porous titanium fiber material was determined and the equation of the sintering neck＇s length was established.
基金Projects(51671152,51304153)supported by the National Natural Science Foundation of China
文摘The high-temperature acoustic absorption performance of porous titanium fiber material was investigated in terms of sample thickness, porosity, temperature, air-cavity thickness and double-layer structure arrangement. The effects on absorption coefficient were systematically assessed. The results show that the sound absorption performance is improved by increasing the sample porosity and/or thickness, and/or increasing the air-cavity thickness. Meanwhile, increasing the temperature gives better acoustic absorption performance in the low frequency range but also lowers the performance in the high frequency range, while double-layer structure enables better acoustic absorption performance.
文摘Titanium metal and alloy are key materials for technological development,which significantly promote the development of the hightech economy in China.The consumption of high-end titanium materials and the developmental level of the titanium industry are important indexes of a country’s comprehensive power.However,at present,the application amount and level of high-end titanium materials in China are limited by many factors,including the dependence of raw materials on imports,high processing cost,and structural imbalance of products.Based on the characteristics of titanium resources and the current situation of the titanium industry,the whole titanium industrial chain in China should be updated.Improving the quality of raw materials is important to produce low-cost,high-end titanium materials using titanium resources with high calcium and magnesium contents in the Panxi region.In addition,the steel-titanium joint production is a vital step to reduce the processing cost of titanium materials.Moreover,the consumption structure of titanium materials should be completed to expand their application.Gradually implementing these suggestions,the overall level of China’s titanium industry will be greatly improved,thereby rapidly establishing an advanced scientific and technological country.
文摘TiN/Al2O3 composite material was prepared by aluminothermic reduction of TiO2 in coke bed. The phase composition, lattice parameter and microstructure of products treated at 1 300 ℃ , 1 400 ℃, 1 500℃ for 3 h respectively were analyzed by XRD, SEM and TEM. The results showed that TiN/Al2O3 composite material can be prepared in coke bed via aluminothermic reduction method. However, the treatment temperatures affect the evolution of aluminothermic reaction and morphology of the materials obviously. The content, grain size and lattice parameter of TiN in materials in coke bed increased with the increase of treatment temperature. Thermodynamic calculation confirmed that metal Al reacted with O2 in coke bed while it was involved in aluminothermic reduction reaction, causing the lack of Al and surplus rutile in the products.
基金sponsored by the National Natural Science Foundation of China the Program for New Century Excellent Talents in University (NCET-12-0627) of Chinathe Fundamental Research Funds for the Central Universities of China
文摘This study investigates the feasibility of using electrochemical machining（ECM） to produce critical aeroengine components from a new burn-resistant titanium alloy（Ti40）, thereby reducing costs and improving efficiency relative to conventional mechanical machining.Through this, it is found that an aqueous mix of sodium chloride and potassium bromide provides the optimal electrolyte and that the surface quality of the Ti40 workpiece is improved by using a pulsed current of1 k Hz rather than a direct current.Furthermore, the quality of cavities produced by ECM and the overall material removal rate are determined to be dependent on a combination of operating voltage, electrolyte inlet pressure, cathode feeding rate and electrolyte concentration.By optimizing these parameters, a surface roughness of 0.371 lm has been achieved in conjunction with a specific removal rate of more than 3.1 mm3/A？min.
基金supported partially by the National High-Tech R&D Program of China(863 Program,No.2015AA033702)the National Basic Research Program of China(Nos.2012CB619103 and 2012CB933901)+1 种基金the National Natural Science Foundation of China(Nos.51271182 and 51501200)the Australian Research Council Discovery Project(Nos.DP110101653 and DP130103592)
文摘Electron beam melting （EBM） has been used to manufacture β-type Ti-24Nb-4Zr-8Sn porous compo- nents with 70% porosity, EBM-produced components have favorable structural features （i.e. smooth strut surfaces, fewer defects） and an （α ＋ β）-type microstructure, similar to that subjected to aging treat- ment. EBM-produced components exhibit more than twice the strength-to-modulus ratio of porous Ti- 6A1-4V components having the same porosity. The processing-microstructure-property relationship and deformation behavior of EBM-produced components are discussed in detail. Such porous titanium com- ponents composed of non-toxic elements and having high strength-to-modulus ratio are highly attractive for biomedical applications.
文摘On September 5,the journalist learned from the Shaanxi Province State-owned Assets Supervision and Administration Commission that,as the key R&D production base of Titanium alloy material for China’s air and space industry,Shaanxi Nonferrous Baoti Group supplied 90%Titanium alloy material usage to China’s air and space industry,making it the main supplier of Titanium alloy for China’s new fighters and big planes.
