Crystallization behavior of amorphous Zr 65 Cu 25 Al 10 alloy under isothermal annealing condition was investigated by DSC and XRD. It is found that two exothermic peaks appear in the DSC curve of amorphous Zr 65 Cu 2...Crystallization behavior of amorphous Zr 65 Cu 25 Al 10 alloy under isothermal annealing condition was investigated by DSC and XRD. It is found that two exothermic peaks appear in the DSC curve of amorphous Zr 65 Cu 25 Al 10 alloy, indicating that the crystallization proceeds through double stage mode. The crystallization process of amorphous Zr 65 Cu 25 Al 10 alloy under isothermal annealing condition is mainly controlled by nucleation and one dimensional growth with the crystallized volume fraction smaller than 70%. With the crystallized volume fraction ranging from 70% to 90%, crystallization process is mainly dominated by the growth of three dimensional pre existing quench in nuclei. And when the crystallized volume fraction reaches above 90%, transient nucleation becomes the master of the crystallization process.展开更多
The texture evaluation of α2 phase in Ti-25Al-10Nb-3V-1Mo sheet during rolling and annealing has been investigated by means of microstructure observation and ODF analysis. From the weak initial {1010} (1210) and {000...The texture evaluation of α2 phase in Ti-25Al-10Nb-3V-1Mo sheet during rolling and annealing has been investigated by means of microstructure observation and ODF analysis. From the weak initial {1010} (1210) and {0001}(1210) textures a {1210}(1010) texture and a {0001}(uvtw)fibre texture are formed after cold rolling. The {0001} (1210) texture is also strengthened simultaneously. The activation process of slip systems is discussed concerning formation of the rolling texture. Because of the disappearance of {0001} (nvtw) fibre texture the primary recrystallization process should occur and the {1210}(1010) texture forms during annealing展开更多
Anodizing is expected to be an effective method to improve the osteoconductivity of the Ti-29Nb-13Ta-4.6Zr (TNTZ) alloy because the bioactivity of anodized Ti is good. However, it is not known how the alloy elements i...Anodizing is expected to be an effective method to improve the osteoconductivity of the Ti-29Nb-13Ta-4.6Zr (TNTZ) alloy because the bioactivity of anodized Ti is good. However, it is not known how the alloy elements influence the surface roughness, composition, hydrophilicity, and osteoconductivity of the anodized film on the Ti alloy. In this study, we investigated the effects of anodizing on the surface properties and the osteoconductivity of the anodized TNTZ alloy, focusing on the functions of the individual alloy elements. The anodized oxides of the Nb, Ta, and Zr metals were hydrophobic at all the voltages applied, in contrast to the anodized oxide of Ti. As well as pure Ti, a TiO2-based oxide film formed on TNTZ after anodizing. However, the oxide film also contained large amounts of Nb species and the molar Nb/Ti ratio in the TNTZ alloy was high, which makes the surface more hydrophobic than the anodized oxide on Ti. In vivo tests showed that the osteoconductivity of the TNTZ alloy was sensitive to both its surface roughness and hydrophilicity. When the TNTZ alloy was anodized, the process increased either the surface hydrophobicity or the surface roughness at the voltage used in this study. These changes in the surface properties did not improve its osteoconductivity.展开更多
The bulk glassy Cu 60 Zr 30 Ti 10 alloy with a diameter up to 4 mm and a length of 70 mm containing nanocrystalline phase was successfully developed by using copper mold casting method. The temperature interval of the...The bulk glassy Cu 60 Zr 30 Ti 10 alloy with a diameter up to 4 mm and a length of 70 mm containing nanocrystalline phase was successfully developed by using copper mold casting method. The temperature interval of the supercooled liquid region before crystallization is above 37 K. The glass transition temperature ( T g) and the reduced glass transition temperature ( T g/ T l) of the cast bulk glassy Cu 60 Zr 30 Ti 10 alloy are 713 K and 0.62. The cast bulk glassy alloy, which has high glassy forming ability, shows expected mechanical properties. The elastic modulus, yield strength, fracture strength and elongation including elastic elongation are 114 GPa, 1 785 MPa, 2 150 MPa and 3.3% respectively in compressive deformation, and 112 GPa, 1 780 MPa, 2 000 MPa and 1.9% respectively in tensile deformation. High resolution transmission electron microscope (HRTEM) and nano beam electron diffraction (NBED) studies indicate that the cast metallic bulk glassy Cu 60 Zr 30 Ti 10 alloy consists of nanocrystals with a size of 4 nm embedded in glassy matrix. The nanoparticle is identified as CuZr and has point space group symmetry of pm3m and its lattice parameter is a =0.3 262 nm . The nanocrystalline phase grew up to 10 nm upon annealing at 430 ℃ for 10 min and caused the alloy brittle.展开更多
Crystallization behavior of amorphous Zr 70 Cu 20 Ni 10 alloy isothermally annealed at 380 ℃ was first investigated by employing the differential scanning calorimetry (DSC) and transmission electron microscopy (TEM)....Crystallization behavior of amorphous Zr 70 Cu 20 Ni 10 alloy isothermally annealed at 380 ℃ was first investigated by employing the differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). It has been found that an exothermic peak appears in the DSC trace when the annealing time is about 17～18 min, indicating a certain phase transformation occurs in the matrix of amorphous Zr 70 Cu 20 Ni 10 alloy. Meanwhile, isothermal annealing experiments for amorphous Zr 70 Cu 20 Ni 10 alloy ranging from 360 ℃ to 400 ℃ with a temperature interval of 10 ℃ were also carried out, from which no exothermic reaction can be observed except for the case of 380 ℃. This behavior indicates that the phase transformation during isothermal annealing of amorphous Zr 70 Cu 20 Ni 10 alloy is strongly temperature and time dependent. Further investigations are required to reveal the nature of such phenomenon.展开更多
The homogeneous plastic flow of fully amorphous and partially crystallized Zr(41.2)Ti(13.8)Cu(12.5)Ni(10)Be(22.5) bulk metallic glass (Vitl) has been investigated by compression tests at high temperatures in supercool...The homogeneous plastic flow of fully amorphous and partially crystallized Zr(41.2)Ti(13.8)Cu(12.5)Ni(10)Be(22.5) bulk metallic glass (Vitl) has been investigated by compression tests at high temperatures in supercooled liquid region. Experimental results show that at sufficiently low strain rates, the supercooled liquid of the fully amorphous alloy reveals Newtonian flow with a linear relationship between the flow stress and strain rate. As the strain rate is increased, a transition from linear Newtonian to nonlinear flow is detected, which can be explained by the transition state theory. Over the entire strain rate interval investigated, however, only nonlinear flow is present in the partially crystallized alloy, and the flow stress for each strain rate is much higher. It is found that the strain rate-stress relationship for the partially crystaltized alloy at the given temperature of 646 K also obeys the sinh law derived from the transition state theory, similar to that of the initial homogeneous amorphous alloy. Thus, it is proposed that the flow behavior of the nanocrystalline/amorphous composite at 646 K is mainly controlled by the viscous flow of the remaining supercooled liquid.展开更多
The effects of picosecond Nd:YAG laser irradiation on chemical and morphological surface characteristics of the commercially pure titanium and Ti–13Nb–13Zr alloy in air and argon atmospheres were studied under diffe...The effects of picosecond Nd:YAG laser irradiation on chemical and morphological surface characteristics of the commercially pure titanium and Ti–13Nb–13Zr alloy in air and argon atmospheres were studied under different laser output energy values.During the interaction of laser irradiation with the investigated materials,a part of the energy was absorbed on the target surface,influencing surface modifications.Laser beam interaction with the target surface resulted in various morphological alterations,resulting in crater formation and the presence of microcracks and hydrodynamic structures.Moreover,different chemical changes were induced on the target materials’surfaces,resulting in the titanium oxide formation in the irradiation-affected area and consequently increasing the irradiation energy absorption.Given the high energy absorption at the site of interaction,the dimensions of the surface damaged area increased.Consequently,surface roughness increased.The appearance of surface oxides also led to the increased material hardness in the surface-modified area.Observed chemical and morphological changes were pronounced after laser irradiation of the Ti–13Nb–13Zr alloy surface.展开更多
The crystallization kinetics of Zr 41 Ti 14 Cu 12.5 Ni 10 Be 22.5 bulk metallic glass has been studied by using DSC and XRD. The results show that two exothermal peaks are observed when the alloy is heated to 500?℃, ...The crystallization kinetics of Zr 41 Ti 14 Cu 12.5 Ni 10 Be 22.5 bulk metallic glass has been studied by using DSC and XRD. The results show that two exothermal peaks are observed when the alloy is heated to 500?℃, one peak results dominantly from the formation of Ti 2Ni ( α phase transition), the other peak is mainly due to the formation of Zr 2Cu ( β phase transition). At the beginning of the crystallization, the activation energy of the α phase is smaller, and it increases with increasing crystallized fraction ( x c). When x c increases to 90%, the crystallization activation energy shows the largest value (220?kJ/mol). The crystallization activation energy of the β phase remains about 227?kJ/mol, as it’s crystallized fraction is below 60%, and then it increases with increasing crystallized fraction, and shows the largest activation energy of 257?kJ/mol, as the x c is 65%.展开更多
The role of α precipitates formed during aging in the fracture toughness and fracture behavior of β-type bio-titanium alloy Ti–29Nb–13Ta–4.6Zr(TNTZ) was studied. Results showed that the fracture toughness of the ...The role of α precipitates formed during aging in the fracture toughness and fracture behavior of β-type bio-titanium alloy Ti–29Nb–13Ta–4.6Zr(TNTZ) was studied. Results showed that the fracture toughness of the TNTZ alloy aged at 723 K decreases to the minimum of 72.07–73.19 kJ·m^(-2)when the aging time is extended to 4–8 h and then gradually increases and reaches 144.89 kJ·m^(-2)after 72 h. The decrease in fracture toughness within the aging time of 4–8 h is caused by the large stress concentration at the tip of acicular α precipitates with a high aspect ratio and the preferential crack propagation along the inhomogeneous acicular α precipitates distributed in “V-shape” and “nearly perpendicular shape”. When the aging time is extended to 8–72 h, the precrack tip is uniformly blunted, and the crack is effectively deflected by α precipitates with multi long axis directions, more high homogeneity, low aspect ratio, and large number density. Analysis of the effect of αprecipitates on the fracture behavior suggested that the number of long axis directions of α precipitates is the key controlling factor for the fracture behavior and fracture toughness of the TNTZ alloy aged for different times.展开更多
As implant substitutes are increasingly applied to the clinic,the infection caused by implants has become one of the most common complications,and the modification of the antibacterial function of the implant can redu...As implant substitutes are increasingly applied to the clinic,the infection caused by implants has become one of the most common complications,and the modification of the antibacterial function of the implant can reduce such complications.In this work,a well-defined bowl-shaped nanostructure coating with photocatalytic and photothermal synergistic antibacterial properties was prepared on Ti-19Zr-10Nb-1Fe(TZNF)alloy.The coating is obtained by spin-coating and sintering TiO_(2)precursors templated from self-assembled microspheres of polystyrenepoly(4-vinylpyridine)(PS-P4VP)amphiphilic block polymer on TZNF alloy.PS-P4VP provides the bowl-shaped TiO_(2)nanostructures doped with C,N elements,reducing the band-gap of TiO_(2),which can absorb near-infrared(NIR)light to release reactive oxygen species and produce photothermal conversion.The bowl structure is expected to enhance the utilization of light via the reflection in the confined space.The bowl-shaped surface has 100%antibacterial rates after 30 min of NIR light irradiation.In addition to antibacterial properties,the bowl-shaped surface has better hydrophilicity and protein adsorption capacity.The amount of protein adsorbed on TZNF with the bowl-shaped structures was six times that of TZNF.Hence,the bowl-shaped nanostructure can promote the proliferation and adhesion of osteoblasts,the cell proliferation rate was increased by 10–30%.展开更多
In this work,a biomimetic coating of hydroxyapatite(HA)-and titania(TiO2)was deposited on low elastic β-phase Ti-35Nb-7Ta-5Zr(β-TNTZ)alloy by plasma spray deposition technique for orthopedic applications.The effect ...In this work,a biomimetic coating of hydroxyapatite(HA)-and titania(TiO2)was deposited on low elastic β-phase Ti-35Nb-7Ta-5Zr(β-TNTZ)alloy by plasma spray deposition technique for orthopedic applications.The effect of TiO2 reinforcement on microstructure,mechanical properties,and bioactivity was investigated.The morphology,coating thickness,elemental composition,and phase composition of the developed coatings were characterized.The biomechanical behavior of the deposited coatings was investigated in terms of surface hardness,elastic modulus,and adhesion strength.It was found from the morphological investigation that the TiO2 reinforcement improves the microstructure and prevents the formation of defects in the coating.The biomimetic HA-TiO2 coated surface possessed pores,size ranging from 200 nm-600 nm that benefits the apatite growth and osseointegration.The EDS spectrum,mapping,and XRD analysis show that the deposited layerβ-TCP,CaO,TTCP,TiO2 phases.The HA-TiO2 coating exhibits a very dense and thick layer of 100μm-125am that exhibits excellent adhesion strength to offer mechanical interlocking to prevent delamination.The alloying of TiO2 improves the hardness from 1.67 GPa to 2.95 GPa that enhances the wear resistance.It was found that HA-TiO2 coating exhibits better hydrophilic and biocompatible surface as compared to HA-coating.展开更多
Mechanical properties of the Zr41Ti14Cu12.5Ni10Be22.5 bulk amorphous alloy at different temperatures were investigated. The compression test was carried out on a Gleebe-3200 machine at 345 and 375℃, respectively, in ...Mechanical properties of the Zr41Ti14Cu12.5Ni10Be22.5 bulk amorphous alloy at different temperatures were investigated. The compression test was carried out on a Gleebe-3200 machine at 345 and 375℃, respectively, in the supercooled liquid region. It is shown that decreasing the compressive rate and increasing temperature have a similar influence trend on the compressive behavior of the bulk amorphous alloy. Room and low temperature tensile strengths were tested on the Instron materials testing system. At low temperature, the tensile strength decreased with decreasing of the testing temperature. Hardness measurement indicated that below the glass transition temperature, the hardness decreased with increasing of the annealing temperature and duration time. It, however, increased when the annealing treatment was performed above the glass transition temperature.展开更多
文摘Crystallization behavior of amorphous Zr 65 Cu 25 Al 10 alloy under isothermal annealing condition was investigated by DSC and XRD. It is found that two exothermic peaks appear in the DSC curve of amorphous Zr 65 Cu 25 Al 10 alloy, indicating that the crystallization proceeds through double stage mode. The crystallization process of amorphous Zr 65 Cu 25 Al 10 alloy under isothermal annealing condition is mainly controlled by nucleation and one dimensional growth with the crystallized volume fraction smaller than 70%. With the crystallized volume fraction ranging from 70% to 90%, crystallization process is mainly dominated by the growth of three dimensional pre existing quench in nuclei. And when the crystallized volume fraction reaches above 90%, transient nucleation becomes the master of the crystallization process.
文摘The texture evaluation of α2 phase in Ti-25Al-10Nb-3V-1Mo sheet during rolling and annealing has been investigated by means of microstructure observation and ODF analysis. From the weak initial {1010} (1210) and {0001}(1210) textures a {1210}(1010) texture and a {0001}(uvtw)fibre texture are formed after cold rolling. The {0001} (1210) texture is also strengthened simultaneously. The activation process of slip systems is discussed concerning formation of the rolling texture. Because of the disappearance of {0001} (nvtw) fibre texture the primary recrystallization process should occur and the {1210}(1010) texture forms during annealing
文摘Anodizing is expected to be an effective method to improve the osteoconductivity of the Ti-29Nb-13Ta-4.6Zr (TNTZ) alloy because the bioactivity of anodized Ti is good. However, it is not known how the alloy elements influence the surface roughness, composition, hydrophilicity, and osteoconductivity of the anodized film on the Ti alloy. In this study, we investigated the effects of anodizing on the surface properties and the osteoconductivity of the anodized TNTZ alloy, focusing on the functions of the individual alloy elements. The anodized oxides of the Nb, Ta, and Zr metals were hydrophobic at all the voltages applied, in contrast to the anodized oxide of Ti. As well as pure Ti, a TiO2-based oxide film formed on TNTZ after anodizing. However, the oxide film also contained large amounts of Nb species and the molar Nb/Ti ratio in the TNTZ alloy was high, which makes the surface more hydrophobic than the anodized oxide on Ti. In vivo tests showed that the osteoconductivity of the TNTZ alloy was sensitive to both its surface roughness and hydrophilicity. When the TNTZ alloy was anodized, the process increased either the surface hydrophobicity or the surface roughness at the voltage used in this study. These changes in the surface properties did not improve its osteoconductivity.
文摘The bulk glassy Cu 60 Zr 30 Ti 10 alloy with a diameter up to 4 mm and a length of 70 mm containing nanocrystalline phase was successfully developed by using copper mold casting method. The temperature interval of the supercooled liquid region before crystallization is above 37 K. The glass transition temperature ( T g) and the reduced glass transition temperature ( T g/ T l) of the cast bulk glassy Cu 60 Zr 30 Ti 10 alloy are 713 K and 0.62. The cast bulk glassy alloy, which has high glassy forming ability, shows expected mechanical properties. The elastic modulus, yield strength, fracture strength and elongation including elastic elongation are 114 GPa, 1 785 MPa, 2 150 MPa and 3.3% respectively in compressive deformation, and 112 GPa, 1 780 MPa, 2 000 MPa and 1.9% respectively in tensile deformation. High resolution transmission electron microscope (HRTEM) and nano beam electron diffraction (NBED) studies indicate that the cast metallic bulk glassy Cu 60 Zr 30 Ti 10 alloy consists of nanocrystals with a size of 4 nm embedded in glassy matrix. The nanoparticle is identified as CuZr and has point space group symmetry of pm3m and its lattice parameter is a =0.3 262 nm . The nanocrystalline phase grew up to 10 nm upon annealing at 430 ℃ for 10 min and caused the alloy brittle.
文摘Crystallization behavior of amorphous Zr 70 Cu 20 Ni 10 alloy isothermally annealed at 380 ℃ was first investigated by employing the differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). It has been found that an exothermic peak appears in the DSC trace when the annealing time is about 17～18 min, indicating a certain phase transformation occurs in the matrix of amorphous Zr 70 Cu 20 Ni 10 alloy. Meanwhile, isothermal annealing experiments for amorphous Zr 70 Cu 20 Ni 10 alloy ranging from 360 ℃ to 400 ℃ with a temperature interval of 10 ℃ were also carried out, from which no exothermic reaction can be observed except for the case of 380 ℃. This behavior indicates that the phase transformation during isothermal annealing of amorphous Zr 70 Cu 20 Ni 10 alloy is strongly temperature and time dependent. Further investigations are required to reveal the nature of such phenomenon.
文摘The homogeneous plastic flow of fully amorphous and partially crystallized Zr(41.2)Ti(13.8)Cu(12.5)Ni(10)Be(22.5) bulk metallic glass (Vitl) has been investigated by compression tests at high temperatures in supercooled liquid region. Experimental results show that at sufficiently low strain rates, the supercooled liquid of the fully amorphous alloy reveals Newtonian flow with a linear relationship between the flow stress and strain rate. As the strain rate is increased, a transition from linear Newtonian to nonlinear flow is detected, which can be explained by the transition state theory. Over the entire strain rate interval investigated, however, only nonlinear flow is present in the partially crystallized alloy, and the flow stress for each strain rate is much higher. It is found that the strain rate-stress relationship for the partially crystaltized alloy at the given temperature of 646 K also obeys the sinh law derived from the transition state theory, similar to that of the initial homogeneous amorphous alloy. Thus, it is proposed that the flow behavior of the nanocrystalline/amorphous composite at 646 K is mainly controlled by the viscous flow of the remaining supercooled liquid.
基金This work was financially supported by the Ministry of Education,Science and Technological Development of the Republic of Serbia through Project Nos.ON174004 and ON172019the PhD fellowship of Slađana Laketić.
文摘The effects of picosecond Nd:YAG laser irradiation on chemical and morphological surface characteristics of the commercially pure titanium and Ti–13Nb–13Zr alloy in air and argon atmospheres were studied under different laser output energy values.During the interaction of laser irradiation with the investigated materials,a part of the energy was absorbed on the target surface,influencing surface modifications.Laser beam interaction with the target surface resulted in various morphological alterations,resulting in crater formation and the presence of microcracks and hydrodynamic structures.Moreover,different chemical changes were induced on the target materials’surfaces,resulting in the titanium oxide formation in the irradiation-affected area and consequently increasing the irradiation energy absorption.Given the high energy absorption at the site of interaction,the dimensions of the surface damaged area increased.Consequently,surface roughness increased.The appearance of surface oxides also led to the increased material hardness in the surface-modified area.Observed chemical and morphological changes were pronounced after laser irradiation of the Ti–13Nb–13Zr alloy surface.
文摘The crystallization kinetics of Zr 41 Ti 14 Cu 12.5 Ni 10 Be 22.5 bulk metallic glass has been studied by using DSC and XRD. The results show that two exothermal peaks are observed when the alloy is heated to 500?℃, one peak results dominantly from the formation of Ti 2Ni ( α phase transition), the other peak is mainly due to the formation of Zr 2Cu ( β phase transition). At the beginning of the crystallization, the activation energy of the α phase is smaller, and it increases with increasing crystallized fraction ( x c). When x c increases to 90%, the crystallization activation energy shows the largest value (220?kJ/mol). The crystallization activation energy of the β phase remains about 227?kJ/mol, as it’s crystallized fraction is below 60%, and then it increases with increasing crystallized fraction, and shows the largest activation energy of 257?kJ/mol, as the x c is 65%.
基金financially supported by the Natural Science Foundation of Liaoning Province,China (No.2022-MS-113)the Major technology projects of Liaoning Province,China (No.2019JH1/10100004)+1 种基金the National Natural Science Foundation of China (No.52271249)the Key Research and Development Program of Shaanxi,China(No.2023-YBGY-488)。
文摘The role of α precipitates formed during aging in the fracture toughness and fracture behavior of β-type bio-titanium alloy Ti–29Nb–13Ta–4.6Zr(TNTZ) was studied. Results showed that the fracture toughness of the TNTZ alloy aged at 723 K decreases to the minimum of 72.07–73.19 kJ·m^(-2)when the aging time is extended to 4–8 h and then gradually increases and reaches 144.89 kJ·m^(-2)after 72 h. The decrease in fracture toughness within the aging time of 4–8 h is caused by the large stress concentration at the tip of acicular α precipitates with a high aspect ratio and the preferential crack propagation along the inhomogeneous acicular α precipitates distributed in “V-shape” and “nearly perpendicular shape”. When the aging time is extended to 8–72 h, the precrack tip is uniformly blunted, and the crack is effectively deflected by α precipitates with multi long axis directions, more high homogeneity, low aspect ratio, and large number density. Analysis of the effect of αprecipitates on the fracture behavior suggested that the number of long axis directions of α precipitates is the key controlling factor for the fracture behavior and fracture toughness of the TNTZ alloy aged for different times.
基金supported by the National Key Research and Development Program of China(No.2018YFC1106600)the National Natural Science Foundation of China(No.52173193).
文摘As implant substitutes are increasingly applied to the clinic,the infection caused by implants has become one of the most common complications,and the modification of the antibacterial function of the implant can reduce such complications.In this work,a well-defined bowl-shaped nanostructure coating with photocatalytic and photothermal synergistic antibacterial properties was prepared on Ti-19Zr-10Nb-1Fe(TZNF)alloy.The coating is obtained by spin-coating and sintering TiO_(2)precursors templated from self-assembled microspheres of polystyrenepoly(4-vinylpyridine)(PS-P4VP)amphiphilic block polymer on TZNF alloy.PS-P4VP provides the bowl-shaped TiO_(2)nanostructures doped with C,N elements,reducing the band-gap of TiO_(2),which can absorb near-infrared(NIR)light to release reactive oxygen species and produce photothermal conversion.The bowl structure is expected to enhance the utilization of light via the reflection in the confined space.The bowl-shaped surface has 100%antibacterial rates after 30 min of NIR light irradiation.In addition to antibacterial properties,the bowl-shaped surface has better hydrophilicity and protein adsorption capacity.The amount of protein adsorbed on TZNF with the bowl-shaped structures was six times that of TZNF.Hence,the bowl-shaped nanostructure can promote the proliferation and adhesion of osteoblasts,the cell proliferation rate was increased by 10–30%.
文摘In this work,a biomimetic coating of hydroxyapatite(HA)-and titania(TiO2)was deposited on low elastic β-phase Ti-35Nb-7Ta-5Zr(β-TNTZ)alloy by plasma spray deposition technique for orthopedic applications.The effect of TiO2 reinforcement on microstructure,mechanical properties,and bioactivity was investigated.The morphology,coating thickness,elemental composition,and phase composition of the developed coatings were characterized.The biomechanical behavior of the deposited coatings was investigated in terms of surface hardness,elastic modulus,and adhesion strength.It was found from the morphological investigation that the TiO2 reinforcement improves the microstructure and prevents the formation of defects in the coating.The biomimetic HA-TiO2 coated surface possessed pores,size ranging from 200 nm-600 nm that benefits the apatite growth and osseointegration.The EDS spectrum,mapping,and XRD analysis show that the deposited layerβ-TCP,CaO,TTCP,TiO2 phases.The HA-TiO2 coating exhibits a very dense and thick layer of 100μm-125am that exhibits excellent adhesion strength to offer mechanical interlocking to prevent delamination.The alloying of TiO2 improves the hardness from 1.67 GPa to 2.95 GPa that enhances the wear resistance.It was found that HA-TiO2 coating exhibits better hydrophilic and biocompatible surface as compared to HA-coating.
基金This work was supported by the National Natural Science Foundation of China(Grant No.50325 103)Hebei Provincial Natural Science Fundation(Grant No.E2004000209/503278)Hebei Education Department Program(Grant No.2004464).
文摘Mechanical properties of the Zr41Ti14Cu12.5Ni10Be22.5 bulk amorphous alloy at different temperatures were investigated. The compression test was carried out on a Gleebe-3200 machine at 345 and 375℃, respectively, in the supercooled liquid region. It is shown that decreasing the compressive rate and increasing temperature have a similar influence trend on the compressive behavior of the bulk amorphous alloy. Room and low temperature tensile strengths were tested on the Instron materials testing system. At low temperature, the tensile strength decreased with decreasing of the testing temperature. Hardness measurement indicated that below the glass transition temperature, the hardness decreased with increasing of the annealing temperature and duration time. It, however, increased when the annealing treatment was performed above the glass transition temperature.
