Volume 35,Issue 11,2006 Table of Contents
2006, 35(11):1681-1685.
Abstract:
TFDC (Thomas-Fermi-Dirac-Cheng) electron theory is applied to analyzing the characteristics of the electrons inside the double layer of the nanometer composite thin films. This paper proposes the new mechanism about the high capacity in both theoretical analysis and experimental measurement.
TFDC (Thomas-Fermi-Dirac-Cheng) electron theory is applied to analyzing the characteristics of the electrons inside the double layer of the nanometer composite thin films. This paper proposes the new mechanism about the high capacity in both theoretical analysis and experimental measurement.
2006, 35(11):1686-1690.
Abstract:
基于微观相场动力学模型，编制了包含共格畸变能的二元立方合金沉淀过程微观组织演化的计算机模拟程序，开展了不同共格畸变能作用下，溶质浓度为20at％的二元镍基合金的粗化机制的计算机模拟。研究发现：共格畸变能为零时，粗化遵循LSW机制，仅仅由颗粒的尺寸大小决定：随着共格畸变能的增大，粗化过程遵循混合机制，由沉淀颗粒的大小和位向（颗粒间的相对位置）共同决定；当共格畸变增大到一定程度时，粗化过程纯粹由颗粒间的位向决定，处于弹性“软”方向上的颗粒优先长大，而处于弹性“软”方向外的颗粒将消失掉。
基于微观相场动力学模型，编制了包含共格畸变能的二元立方合金沉淀过程微观组织演化的计算机模拟程序，开展了不同共格畸变能作用下，溶质浓度为20at％的二元镍基合金的粗化机制的计算机模拟。研究发现：共格畸变能为零时，粗化遵循LSW机制，仅仅由颗粒的尺寸大小决定：随着共格畸变能的增大，粗化过程遵循混合机制，由沉淀颗粒的大小和位向（颗粒间的相对位置）共同决定；当共格畸变增大到一定程度时，粗化过程纯粹由颗粒间的位向决定，处于弹性“软”方向上的颗粒优先长大，而处于弹性“软”方向外的颗粒将消失掉。
3 Tensile Strain Effects on Critical Current of Ag and Ag Alloy-Sheathed Bi-2223 Superconducting Tapes
2006, 35(11):1691-1694.
Abstract:
The tensile stress-strain characteristics of Ag and AgMn alloy-sheathed Bi-2223 tapes have been studied, and the effects of sheath material, filament number and Ag/core ratio on the critical current of Bi-2223 tapes have been compared. Using the Ag-alloy tube as an outer sheath of Bi-2223 tapes can increase the residual thermal compressive stresses in the filaments, avoid a wavy interface between the Ag sheath and oxide core, and limit the stress concentrations induced by the interface inhomogeneity, thus the micro-crack will be formed at higher stress levels and the tensile strain tolerances of tapes can be improved remarkably. In this study, the critical tensile stress can be improved from 62 MPa to 124 MPa, and the irreversible tensile strain can be improved from 0.31% to 0.52% by using the AgMn-alloy as an outer sheath instead of pure Ag in 37-filamentary tapes. In addition, we found that Bi-2223 tapes can tolerate higher tensile strain level by increasing the filament number and Ag/core ration.
The tensile stress-strain characteristics of Ag and AgMn alloy-sheathed Bi-2223 tapes have been studied, and the effects of sheath material, filament number and Ag/core ratio on the critical current of Bi-2223 tapes have been compared. Using the Ag-alloy tube as an outer sheath of Bi-2223 tapes can increase the residual thermal compressive stresses in the filaments, avoid a wavy interface between the Ag sheath and oxide core, and limit the stress concentrations induced by the interface inhomogeneity, thus the micro-crack will be formed at higher stress levels and the tensile strain tolerances of tapes can be improved remarkably. In this study, the critical tensile stress can be improved from 62 MPa to 124 MPa, and the irreversible tensile strain can be improved from 0.31% to 0.52% by using the AgMn-alloy as an outer sheath instead of pure Ag in 37-filamentary tapes. In addition, we found that Bi-2223 tapes can tolerate higher tensile strain level by increasing the filament number and Ag/core ration.
2006, 35(11):1700-1703.
Abstract:
The critical conditions of solidification orientation for Solidification of giant magnetostrictive materials R-Fe alloy in a magnetic field have been investigated. The experiment results show that suppressing the turbulence in melt is a key factor in texturing the magnetic materials. In solidification course, the turbulent degree in melt is dominated by the cooling rate, and a modified Ra^m number is used to simulate the state of turbulence at various cooling rates. While the value of the critical Ra^c number in magnetic field is large than that of the modified Ra^m number in melt, the temperature oscillations in melt will be restrained, and the texture along the easy magnetic axis will be dominant in the sample. Therefore the critical conditions of effective orienting action for magnetic materials by solidification in a magnetic field can be definite as the rate of the critical Ra^c number in a magnetic field to Ra^m number in melt is close to 1.
The critical conditions of solidification orientation for Solidification of giant magnetostrictive materials R-Fe alloy in a magnetic field have been investigated. The experiment results show that suppressing the turbulence in melt is a key factor in texturing the magnetic materials. In solidification course, the turbulent degree in melt is dominated by the cooling rate, and a modified Ra^m number is used to simulate the state of turbulence at various cooling rates. While the value of the critical Ra^c number in magnetic field is large than that of the modified Ra^m number in melt, the temperature oscillations in melt will be restrained, and the texture along the easy magnetic axis will be dominant in the sample. Therefore the critical conditions of effective orienting action for magnetic materials by solidification in a magnetic field can be definite as the rate of the critical Ra^c number in a magnetic field to Ra^m number in melt is close to 1.
2006, 35(11):1704-1707.
Abstract:
采用传统陶瓷工艺制备了锰掺杂0.8(Na0.5Bi0.5)TiO3-0.1BaTiO3-0.1(K0.5Bi0.5)TiO3(BNT-B-BKT)无铅压电陶瓷材料,研究了材料的介电、压电和铁电性能.发现锰掺杂大幅降低了0.8(Na0.5Bi0.5)TiO3-0.1BaTiO3-0.1(K0.5Bi0.5)TiO3陶瓷的电导率和矫顽场,最佳掺杂量为0.1%(质量分数),该配方的最佳烧结温度为1150℃.这一温度下烧结所得样品在130℃时的电导率仅为1.36×10-1Ω-1cm-1,约为掺杂前的1/40,矫顽场Ec仅为2.78 kV/mm,剩余极化强度Pr为38μC/cm2,压电系数d33达到143 pC/N.
采用传统陶瓷工艺制备了锰掺杂0.8(Na0.5Bi0.5)TiO3-0.1BaTiO3-0.1(K0.5Bi0.5)TiO3(BNT-B-BKT)无铅压电陶瓷材料,研究了材料的介电、压电和铁电性能.发现锰掺杂大幅降低了0.8(Na0.5Bi0.5)TiO3-0.1BaTiO3-0.1(K0.5Bi0.5)TiO3陶瓷的电导率和矫顽场,最佳掺杂量为0.1%(质量分数),该配方的最佳烧结温度为1150℃.这一温度下烧结所得样品在130℃时的电导率仅为1.36×10-1Ω-1cm-1,约为掺杂前的1/40,矫顽场Ec仅为2.78 kV/mm,剩余极化强度Pr为38μC/cm2,压电系数d33达到143 pC/N.
2006, 35(11):1708-1711.
Abstract:
Using Ti, Al and C powders as starting materials, the effect of intermetallic compound TiAl3 addition on the combustion synthesis of Ti3AlC has been studied. The experiment results show that the main phase of the combustion product involves Ti2AlC and TiC without Ti3AlC, if the molar ratio of Ti, Al, C is equal to 3:1:1. However, the product Ti3AlC is produced by combustion synthesis if a small amount of TiAl3 is added to the starting mixtures without changing the overall stoichiometry. The Ti3AlC becomes the main phase in the final product upon adding 23.5% TiAl3 (mass fraction) in the raw mixtures. The amount of Ti3AlC increases with increasing of addition of TiAl3 in the raw mixtures. The above experimental phenomena were explained through thermodynamic and kinetic analysis.
Using Ti, Al and C powders as starting materials, the effect of intermetallic compound TiAl3 addition on the combustion synthesis of Ti3AlC has been studied. The experiment results show that the main phase of the combustion product involves Ti2AlC and TiC without Ti3AlC, if the molar ratio of Ti, Al, C is equal to 3:1:1. However, the product Ti3AlC is produced by combustion synthesis if a small amount of TiAl3 is added to the starting mixtures without changing the overall stoichiometry. The Ti3AlC becomes the main phase in the final product upon adding 23.5% TiAl3 (mass fraction) in the raw mixtures. The amount of Ti3AlC increases with increasing of addition of TiAl3 in the raw mixtures. The above experimental phenomena were explained through thermodynamic and kinetic analysis.
2006, 35(11):1712-1715.
Abstract:
对Cu-7．9％Co包晶合金不同定向凝固速率下的凝固组织进行了研究。结果表明：在定向凝固速率1μm／s～100μm／s下，随凝固速率的提高，初生α-Co相体积分数减少，使形态从定向生长的枝晶转变为等轴枝晶，相应地β-Cu包晶相的生长界面形态由平界面转变为枝状界面。利用最高界面生长温度假设，计算得到了凝固速率在0．55μm／s～5000μm／s范围内α-Co相领先于β-Cu相生长，与实验结果较为吻合；并当凝固速率大于5000μm／s时，β-Cu相的凝固界面生长温度高于α-Co而成为领先相，可以不通过包晶反应直接从熔体中凝固析出。
对Cu-7．9％Co包晶合金不同定向凝固速率下的凝固组织进行了研究。结果表明：在定向凝固速率1μm／s～100μm／s下，随凝固速率的提高，初生α-Co相体积分数减少，使形态从定向生长的枝晶转变为等轴枝晶，相应地β-Cu包晶相的生长界面形态由平界面转变为枝状界面。利用最高界面生长温度假设，计算得到了凝固速率在0．55μm／s～5000μm／s范围内α-Co相领先于β-Cu相生长，与实验结果较为吻合；并当凝固速率大于5000μm／s时，β-Cu相的凝固界面生长温度高于α-Co而成为领先相，可以不通过包晶反应直接从熔体中凝固析出。
2006, 35(11):1716-1719.
Abstract:
In this paper the galvanic corrosion behavior laws of AM50 magnesium alloy coupled with different alloys in Beijing atmospheric environment were investigated. The results show that the magnesium alloys act as anode. The atmospheric galvanic effect of magnesium alloys coupled with LY12 aluminium alloy is the least in all of testing cathode alloys. The atmospheric galvanic effects in Beijing compared with other cities indicate that atmospheric environment is the most important factor. The atmospheric galvanic effects for magnesium alloys are affected by cathode alloy, testing time, sample size and environment condition. SEM, XRD and optical microscope were used to investigate the morphology changes on the surface of AM50 magnesium alloy.
In this paper the galvanic corrosion behavior laws of AM50 magnesium alloy coupled with different alloys in Beijing atmospheric environment were investigated. The results show that the magnesium alloys act as anode. The atmospheric galvanic effect of magnesium alloys coupled with LY12 aluminium alloy is the least in all of testing cathode alloys. The atmospheric galvanic effects in Beijing compared with other cities indicate that atmospheric environment is the most important factor. The atmospheric galvanic effects for magnesium alloys are affected by cathode alloy, testing time, sample size and environment condition. SEM, XRD and optical microscope were used to investigate the morphology changes on the surface of AM50 magnesium alloy.
2006, 35(11):1720-1724.
Abstract:
采用旋铸急冷工艺在大气环境中制备出了（Ni0.75Fe0.25）78Si10B12非晶合金带材。X射线衍射（XRD）分析表明样品为完全非晶。用Diamond TG／DTA差热分析仪在高纯氩气保护下测量了非晶薄带的热稳定性参数Tg，Txi，Tpi并分析其晶化行为，加热速度分别为10K／min，20K／min，30K／min，40K／min。（Ni0.75Fe0.25）78Si10B12非晶合金的Tg，Txi，Tpi均随加热速率的增加而增加，说明其玻璃转变和晶化行为均有动力学效应。分别用Kissinger法和Ozawa法计算该非晶合金的晶化激活能，2种方法的计算结果是一致的。对试样在通高纯氩气保护下，进行等温（695K，715K，745K，765K，保温60min）退火处理，利用XRD分析了非晶合金等温晶化时相转变及组织转变。合金在715K和745K温度退火时，在非晶基体上析出了单一的γ-（Fe，Ni）固溶体，平均晶粒尺寸分别约为10.3nm和18．5nm，765K退火处理后的结晶相为γ-（Fe，Ni），Fe2Si，Ni2Si和Fe3B，平均晶粒尺寸约29．6nm。
采用旋铸急冷工艺在大气环境中制备出了（Ni0.75Fe0.25）78Si10B12非晶合金带材。X射线衍射（XRD）分析表明样品为完全非晶。用Diamond TG／DTA差热分析仪在高纯氩气保护下测量了非晶薄带的热稳定性参数Tg，Txi，Tpi并分析其晶化行为，加热速度分别为10K／min，20K／min，30K／min，40K／min。（Ni0.75Fe0.25）78Si10B12非晶合金的Tg，Txi，Tpi均随加热速率的增加而增加，说明其玻璃转变和晶化行为均有动力学效应。分别用Kissinger法和Ozawa法计算该非晶合金的晶化激活能，2种方法的计算结果是一致的。对试样在通高纯氩气保护下，进行等温（695K，715K，745K，765K，保温60min）退火处理，利用XRD分析了非晶合金等温晶化时相转变及组织转变。合金在715K和745K温度退火时，在非晶基体上析出了单一的γ-（Fe，Ni）固溶体，平均晶粒尺寸分别约为10.3nm和18．5nm，765K退火处理后的结晶相为γ-（Fe，Ni），Fe2Si，Ni2Si和Fe3B，平均晶粒尺寸约29．6nm。
2006, 35(11):1725-1729.
Abstract:
通过化学镀方法在玻璃纤维表面沉积了Ni-Fe-W-P合金,所用镀液经钯盐法测试,稳定性很好,所得镀合金玻璃纤维经热震实验后表面无鼓泡、起皮现象,说明镀层的抗冲击强度高,结合力良好。利用扫描电镜观察了镀层的表面形貌,同时使用X射线能谱仪对镀层成分含量进行了分析,镀层中钨的质量分数最大可达22.2%,并得出了硫酸镍、硫酸亚铁、钨酸钠浓度对镀层导电性能的影响情况,制备的镀合金玻璃纤维电阻率为28.3×10-3?·cm。对玻璃纤维合金层进行的XRD分析表明,在镀态下为非晶态结构,玻璃纤维热稳定性好,适宜的工作温度范围低于250oC。最后对所得Ni-Fe-W-P合金玻璃纤维的电磁参数进行了初步的测定与分析,所得镀金属玻璃纤维的磁损耗为0.05475;介电损耗为2.18424,镀层合金为软磁性材料。
通过化学镀方法在玻璃纤维表面沉积了Ni-Fe-W-P合金,所用镀液经钯盐法测试,稳定性很好,所得镀合金玻璃纤维经热震实验后表面无鼓泡、起皮现象,说明镀层的抗冲击强度高,结合力良好。利用扫描电镜观察了镀层的表面形貌,同时使用X射线能谱仪对镀层成分含量进行了分析,镀层中钨的质量分数最大可达22.2%,并得出了硫酸镍、硫酸亚铁、钨酸钠浓度对镀层导电性能的影响情况,制备的镀合金玻璃纤维电阻率为28.3×10-3?·cm。对玻璃纤维合金层进行的XRD分析表明,在镀态下为非晶态结构,玻璃纤维热稳定性好,适宜的工作温度范围低于250oC。最后对所得Ni-Fe-W-P合金玻璃纤维的电磁参数进行了初步的测定与分析,所得镀金属玻璃纤维的磁损耗为0.05475;介电损耗为2.18424,镀层合金为软磁性材料。
2006, 35(11):1730-1734.
Abstract:
Through tensile test, tensile-unload test and SEM observation, the effects of loading rate on fracture mechanism of TiAl-based alloys with fully lamellar and duplex microstructures were investigated. The result reveals that when the rate is lower, microcrack density is larger and microcracks have sufficient time to initiate along many grain boundaries or lamellar interface, and propagate basically along interlamellar within the grain. There are no river patterns on the fracture surface. A majority of the fracture surface belongs to interlamellar fracture, and grain structure is not obvious on fracture surface, such case effects on the mechanical properties are dominant. While the microcracks have no time to initiate and propagate in the case of high loading rate, many river patterns come into being in the course of fracture, and we can also find the grain structure no longer obvious on the fracture surface. Because many microcracks initiate ahead, the size of fracture facet is smaller, so the effects are much less obvious, in this case.
Through tensile test, tensile-unload test and SEM observation, the effects of loading rate on fracture mechanism of TiAl-based alloys with fully lamellar and duplex microstructures were investigated. The result reveals that when the rate is lower, microcrack density is larger and microcracks have sufficient time to initiate along many grain boundaries or lamellar interface, and propagate basically along interlamellar within the grain. There are no river patterns on the fracture surface. A majority of the fracture surface belongs to interlamellar fracture, and grain structure is not obvious on fracture surface, such case effects on the mechanical properties are dominant. While the microcracks have no time to initiate and propagate in the case of high loading rate, many river patterns come into being in the course of fracture, and we can also find the grain structure no longer obvious on the fracture surface. Because many microcracks initiate ahead, the size of fracture facet is smaller, so the effects are much less obvious, in this case.
2006, 35(11):1735-1739.
Abstract:
Nitrogen-doped TiO2 was prepared by Ti(SO4)2 solution reacting with NH3 aqueous solution. The optical absorption edge of nitrogen-doped TiO2 shifted 20 nm toward the infrared and also absorbs the visible light from 400 nm to 530 nm compared with undoped TiO2.Band gap of undoped TiO2 was 3.24 eV and nitrogen-doped TiO2 was 3.14 eV. X-ray photoelectron spectroscopy(XPS) measurements show that the nitrogen in N-doped TiO2 is in dissociative interstitial state. That the new absorption band at 400 nm ~530 nm is induced by oxygen vacancies in N-doped TiO2, which exhibits a narrow band close to the conduction band. The MTT assay was used for detecting the activity of N-doped TiO2 on the growth of leukemic HL60 in vitro. The results indicate that N-doped TiO2 can improve the efficiency of destructing leukemic HL60 cells no matter there is or not visible-light irradiation.
Nitrogen-doped TiO2 was prepared by Ti(SO4)2 solution reacting with NH3 aqueous solution. The optical absorption edge of nitrogen-doped TiO2 shifted 20 nm toward the infrared and also absorbs the visible light from 400 nm to 530 nm compared with undoped TiO2.Band gap of undoped TiO2 was 3.24 eV and nitrogen-doped TiO2 was 3.14 eV. X-ray photoelectron spectroscopy(XPS) measurements show that the nitrogen in N-doped TiO2 is in dissociative interstitial state. That the new absorption band at 400 nm ~530 nm is induced by oxygen vacancies in N-doped TiO2, which exhibits a narrow band close to the conduction band. The MTT assay was used for detecting the activity of N-doped TiO2 on the growth of leukemic HL60 in vitro. The results indicate that N-doped TiO2 can improve the efficiency of destructing leukemic HL60 cells no matter there is or not visible-light irradiation.
13 The Mechanism of Sc Increaseing the Glass Forming Ability of a Zirconium Based Bulk Amorphous Alloy
2006, 35(11):1740-1743.
Abstract:
Quintary Zr52.5Cu17.9Ni14.6Al10Ti5 bulk amorphous alloys were synthesized with industrial sponge zirconium. The wedge-shaped samples added with Sc were prepared. The mechanism of Sc increaseing the GFA of the ahoy was analyzed by means of X-ray diffraction. SEM and Energy Spectrum Analysis. The results showed that adding Sc to the alloy could cause the transformation of phase structure and the composition of the pre-separation phase in the transitional region of the quintary alloy. Sc with great capacity of deoxidization could decrease the existence of Zirconium oxide or Zirconium/oxygen clusters in the alloy, and eliminate heterogeneous nucleants in the melt. Consequently. adding Sc to the alloy could increase the GFA of the quintary alloy.
Quintary Zr52.5Cu17.9Ni14.6Al10Ti5 bulk amorphous alloys were synthesized with industrial sponge zirconium. The wedge-shaped samples added with Sc were prepared. The mechanism of Sc increaseing the GFA of the ahoy was analyzed by means of X-ray diffraction. SEM and Energy Spectrum Analysis. The results showed that adding Sc to the alloy could cause the transformation of phase structure and the composition of the pre-separation phase in the transitional region of the quintary alloy. Sc with great capacity of deoxidization could decrease the existence of Zirconium oxide or Zirconium/oxygen clusters in the alloy, and eliminate heterogeneous nucleants in the melt. Consequently. adding Sc to the alloy could increase the GFA of the quintary alloy.
2006, 35(11):1744-1747.
Abstract:
Spontaneous Al2O3 reinforced TiAl composite was prepared by reaction synthesis with hot pressing. The effect of doping Nb2O5 on microstructure was investigated as well. Adopting DTA, XRD analysis, their reaction courses were analysed and discussed. SEM, XRD, metallography analysis and other test showed that it is niobium oxide improved aluminium thermal reaction and released much higher energy which made the composite could be sintered under lower temperature. Meanwhile, the doping of Nb2O5 has a function to control and alter the proportion of the matrix (TiAl: Ti3Al)phase, strengthen the forming of spontaneous alumina composition in the material, and produce greater influence on the microstructure.
Spontaneous Al2O3 reinforced TiAl composite was prepared by reaction synthesis with hot pressing. The effect of doping Nb2O5 on microstructure was investigated as well. Adopting DTA, XRD analysis, their reaction courses were analysed and discussed. SEM, XRD, metallography analysis and other test showed that it is niobium oxide improved aluminium thermal reaction and released much higher energy which made the composite could be sintered under lower temperature. Meanwhile, the doping of Nb2O5 has a function to control and alter the proportion of the matrix (TiAl: Ti3Al)phase, strengthen the forming of spontaneous alumina composition in the material, and produce greater influence on the microstructure.
2006, 35(11):1748-1752.
Abstract:
The rolling Deformation and strengthening mechanism of typical wrought magnesium alloy AZ31, AZ31(0.8%Ce) and AZ31(0.8%Nd) were studied. The microstructures, mechanical properties and the effects of rare earth Ce and Nd on AZ31 alloy were investigated. The results show that the work hardening of experimental alloys is serious and brittle breaking happen easily. Doping of rare earth can improve both the strength and ductility of AZ31 Alloy. The refine grain strengthening, working hardening and rare earth phase strengthening are the main strengthening mechanism of A231 series alloy.
The rolling Deformation and strengthening mechanism of typical wrought magnesium alloy AZ31, AZ31(0.8%Ce) and AZ31(0.8%Nd) were studied. The microstructures, mechanical properties and the effects of rare earth Ce and Nd on AZ31 alloy were investigated. The results show that the work hardening of experimental alloys is serious and brittle breaking happen easily. Doping of rare earth can improve both the strength and ductility of AZ31 Alloy. The refine grain strengthening, working hardening and rare earth phase strengthening are the main strengthening mechanism of A231 series alloy.
2006, 35(11):1753-1756.
Abstract:
In this paper, the relation between the resistance and the temperature of Stainless Steel (SS) and its fabric are studied. It is found that the resistance of Stainless Steel (SS) fiber has a positive linear relationship with temperature, and that of SS fabric has a negative linear relationship with temperature within a definite range. The textile structure is useful to increase the sensitivity and accuracy of the temperature sensing. The main mechanism of the fabric sensing has been deduced to be the change of the contact resistance between yarns during temperature changing.
In this paper, the relation between the resistance and the temperature of Stainless Steel (SS) and its fabric are studied. It is found that the resistance of Stainless Steel (SS) fiber has a positive linear relationship with temperature, and that of SS fabric has a negative linear relationship with temperature within a definite range. The textile structure is useful to increase the sensitivity and accuracy of the temperature sensing. The main mechanism of the fabric sensing has been deduced to be the change of the contact resistance between yarns during temperature changing.
2006, 35(11):1757-1760.
Abstract:
采用纤维推出法测量了SiCf／Ti-6Al-4V复合材料的界面剪切强度。结果表明，热压态碳涂层和未涂层纤维与基体的界面剪切强度分别为118．2MPa和230MPa，界面脱粘发生在碳涂层或纤维与界面反应层之间。500℃，600℃和800℃退火处理后，界面剪切强度均低于热压态的强度，随退火时间的增加，500℃处理后的界面剪切强度呈下降趋势，600℃和800℃处理后呈微弱上升趋势，而且800℃处理后，界面脱粘可发生在基体／界面反应层和碳涂层或纤维／界面反应产层2个界面。
采用纤维推出法测量了SiCf／Ti-6Al-4V复合材料的界面剪切强度。结果表明，热压态碳涂层和未涂层纤维与基体的界面剪切强度分别为118．2MPa和230MPa，界面脱粘发生在碳涂层或纤维与界面反应层之间。500℃，600℃和800℃退火处理后，界面剪切强度均低于热压态的强度，随退火时间的增加，500℃处理后的界面剪切强度呈下降趋势，600℃和800℃处理后呈微弱上升趋势，而且800℃处理后，界面脱粘可发生在基体／界面反应层和碳涂层或纤维／界面反应产层2个界面。
2006, 35(11):1761-1764.
Abstract:
A novel type of self-sharpen tungsten alloy (SSTA) was fabricated with the design of matrix elements. The microstructures and properties of the SSTAs were studied. The results show that the dynamic compression strength of the SSTAs are higher than that of the conventional tungsten alloys (WHAs), and the failures of SSTAs appear as the form of splits along the loading direction without any visible plastic deformation under the condition of dynamic compression. The special failure mechanism is beneficial to the improvement of the SSTA ability to self-sharpen during ballistic tests.
A novel type of self-sharpen tungsten alloy (SSTA) was fabricated with the design of matrix elements. The microstructures and properties of the SSTAs were studied. The results show that the dynamic compression strength of the SSTAs are higher than that of the conventional tungsten alloys (WHAs), and the failures of SSTAs appear as the form of splits along the loading direction without any visible plastic deformation under the condition of dynamic compression. The special failure mechanism is beneficial to the improvement of the SSTA ability to self-sharpen during ballistic tests.
2006, 35(11):1770-1774.
Abstract:
The effect of applied anodic bias upon the photoelectrocatalytic degradation of methylene blue under ultraviolet illumination on nanoporous undoped TiO2/Ti electrode was studied in the present paper. The influence of doping different transition metal ions in TiO2/Ti on the degradation of methylene blue was also investigated.. The degradation degree was characterized with decolorization of methlylene blue. The results indicate that the degradation efficiency increases with increasing of the applied anodic bias up to 3.5 V, then decreases gradually. Doping TiO2 with Mn2+ and Cr3+ will enhance the efficiency of photoelectrocatalytic, while depositing Ni2+ on the TiO2 film shows a decrease of photoelectrocatalytic efficiency. The above metioned phenomena are attributed to ionic radii and the electron work functions values of the differently doped ions.
The effect of applied anodic bias upon the photoelectrocatalytic degradation of methylene blue under ultraviolet illumination on nanoporous undoped TiO2/Ti electrode was studied in the present paper. The influence of doping different transition metal ions in TiO2/Ti on the degradation of methylene blue was also investigated.. The degradation degree was characterized with decolorization of methlylene blue. The results indicate that the degradation efficiency increases with increasing of the applied anodic bias up to 3.5 V, then decreases gradually. Doping TiO2 with Mn2+ and Cr3+ will enhance the efficiency of photoelectrocatalytic, while depositing Ni2+ on the TiO2 film shows a decrease of photoelectrocatalytic efficiency. The above metioned phenomena are attributed to ionic radii and the electron work functions values of the differently doped ions.
2006, 35(11):1779-1782.
Abstract:
The effect of magnesium on thermodynamics and kinetics of oxidation of melted Al-Mg-Si alloy, the microstructure and properties of Al2O3/Al-Mg-Si composites were studied in this paper. It has been found that magnesium promotes nucleating and growing of Al2O3 in Al2O3/Al composite by analysis of thermodynamics and kinetics. The properties of Al2O3/Al composite were improved by microstructure refining due to spinel (MgAl2O4) decomposing. But too high or too low content of Mg in the alloy is disadvantageous for Al2O3 nucleating and growth.
The effect of magnesium on thermodynamics and kinetics of oxidation of melted Al-Mg-Si alloy, the microstructure and properties of Al2O3/Al-Mg-Si composites were studied in this paper. It has been found that magnesium promotes nucleating and growing of Al2O3 in Al2O3/Al composite by analysis of thermodynamics and kinetics. The properties of Al2O3/Al composite were improved by microstructure refining due to spinel (MgAl2O4) decomposing. But too high or too low content of Mg in the alloy is disadvantageous for Al2O3 nucleating and growth.
2006, 35(11):1783-1787.
Abstract:
利用碳热还原法,通过两步反应合成了LiVPO4F/C复合正极材料.主要研究了球磨、碳含量和电解液对样品结构和电化学性能的影响.结果表明球磨2 h在750℃下能合成纯的LiVPO4F产品,剩余碳的存在使LiVPO4F的粒径减小且分布较为均匀,同时提高了颗粒之间的导电性.对样品进行电化学性能测试表明,含碳量为1.83%的LiVPO4F/C的样品比容量和循环性能都得到显著改善;合适的电解液可以明显提高样品LiVPO4F的电化学性能.含碳量为1.83%的LiVPO4F/C的复合材料以1 mol.L-1LiPF6/EC+EMC+DMC(体积比1∶1∶1)为电解液,在0.2 C的倍率下放电时,其首次放电容量为119 mAh.g-1,放电平台在4.2 V左右(vs.Li),循环30次后比容量为89 mAh.g-1.
利用碳热还原法,通过两步反应合成了LiVPO4F/C复合正极材料.主要研究了球磨、碳含量和电解液对样品结构和电化学性能的影响.结果表明球磨2 h在750℃下能合成纯的LiVPO4F产品,剩余碳的存在使LiVPO4F的粒径减小且分布较为均匀,同时提高了颗粒之间的导电性.对样品进行电化学性能测试表明,含碳量为1.83%的LiVPO4F/C的样品比容量和循环性能都得到显著改善;合适的电解液可以明显提高样品LiVPO4F的电化学性能.含碳量为1.83%的LiVPO4F/C的复合材料以1 mol.L-1LiPF6/EC+EMC+DMC(体积比1∶1∶1)为电解液,在0.2 C的倍率下放电时,其首次放电容量为119 mAh.g-1,放电平台在4.2 V左右(vs.Li),循环30次后比容量为89 mAh.g-1.
2006, 35(11):1788-1791.
Abstract:
Efficient process of explosion synthesis has been established for the synthesis of anatase and rutile as well as their mixtures. The powders were characterized by X-ray diffraction (XRD), BET surface areas. The results showed that the as-prepared grain size was from 8.4 nm to 50 nm, and the maximal SBET was 107.8 m2/g, the average pore size distribution of the sample was 6 nm to 15 nm. With increasing the proportion of detonator, the size of TiO2 crystallite increased, the BET surface areas decreased, the pore size increased, meanwhile the contents of rutile increased and anatase decreased.
Efficient process of explosion synthesis has been established for the synthesis of anatase and rutile as well as their mixtures. The powders were characterized by X-ray diffraction (XRD), BET surface areas. The results showed that the as-prepared grain size was from 8.4 nm to 50 nm, and the maximal SBET was 107.8 m2/g, the average pore size distribution of the sample was 6 nm to 15 nm. With increasing the proportion of detonator, the size of TiO2 crystallite increased, the BET surface areas decreased, the pore size increased, meanwhile the contents of rutile increased and anatase decreased.
2006, 35(11):1792-1796.
Abstract:
将一定配比的LiOH·H2O,V2O5,H3PO4和蔗糖(C12H22O11)通过球磨均匀混合,烘干后埋入石墨粉中,在功率为800W的家用微波炉中高火加热15 min,通过碳热还原合成Li3V2(PO4)3.用X射线衍射和扫描电镜对材料的结构和形貌进行了表征.充放电测试表明,在电压范围为3V～4.3V和3V～4.8v时,Li3V2(PO4)3正极材料具有较高的比容量、优良的循环性能和倍率特性.在电压范围为1.5 V～4.8 V时,Li3V2(PO4)3正极材料具有很高的比容量,但循环性能较差.该材料有望用于锂离子电池部分取代昂贵的LiCoO2,也可望应用于动力型和储能型锂离子电池.
将一定配比的LiOH·H2O,V2O5,H3PO4和蔗糖(C12H22O11)通过球磨均匀混合,烘干后埋入石墨粉中,在功率为800W的家用微波炉中高火加热15 min,通过碳热还原合成Li3V2(PO4)3.用X射线衍射和扫描电镜对材料的结构和形貌进行了表征.充放电测试表明,在电压范围为3V～4.3V和3V～4.8v时,Li3V2(PO4)3正极材料具有较高的比容量、优良的循环性能和倍率特性.在电压范围为1.5 V～4.8 V时,Li3V2(PO4)3正极材料具有很高的比容量,但循环性能较差.该材料有望用于锂离子电池部分取代昂贵的LiCoO2,也可望应用于动力型和储能型锂离子电池.
2006, 35(11):1797-1799.
Abstract:
The diffusion characteristics of Ga in SiO2 films and at the interface of SiO2-Si is characterized and analyzed by means of SIMS, SRP and AFM respectively. The results indicate that the new element Ga born of pyroreaction of H2 and Ga2O3 is absorbed rapidly by SiO2 films and reach the interface of SiO2-Si, its absorb-export flux is directly proportional to doping time under a certain condition; Ga diffuses effectively in the Si body according to solid-solid diffusion principle at the interface of SiO2-Si and depend on the higher solubility in Si; by well combination of the too above mentioned, Ga diffused into the Si body through ideal surface and gained diffused result of high homogeneity and high repeatability.
The diffusion characteristics of Ga in SiO2 films and at the interface of SiO2-Si is characterized and analyzed by means of SIMS, SRP and AFM respectively. The results indicate that the new element Ga born of pyroreaction of H2 and Ga2O3 is absorbed rapidly by SiO2 films and reach the interface of SiO2-Si, its absorb-export flux is directly proportional to doping time under a certain condition; Ga diffuses effectively in the Si body according to solid-solid diffusion principle at the interface of SiO2-Si and depend on the higher solubility in Si; by well combination of the too above mentioned, Ga diffused into the Si body through ideal surface and gained diffused result of high homogeneity and high repeatability.
25 Structure and Performance of NiTi Shape Memory Alloy Thin Films Sputter-Deposited by Situ Heating
2006, 35(11):1800-1802.
Abstract:
研究了原位加热溅射的NiTi形状记忆合金薄膜的结构，讨论了制备工艺及织构对薄膜相变特征的影响，采用电阻法及X射线衍射分析了薄膜的结构及相变过程，确定了最适合于微器件的溅射工艺。结果发现：溅射时采用原位加热可直接获得具有织构的晶化薄膜，提高溅射功率将使薄膜的相变温度升高。
研究了原位加热溅射的NiTi形状记忆合金薄膜的结构，讨论了制备工艺及织构对薄膜相变特征的影响，采用电阻法及X射线衍射分析了薄膜的结构及相变过程，确定了最适合于微器件的溅射工艺。结果发现：溅射时采用原位加热可直接获得具有织构的晶化薄膜，提高溅射功率将使薄膜的相变温度升高。
2006, 35(11):1803-1805.
Abstract:
用非自耗真空电弧炉制备LaMn2Ge2合金,采用X射线衍射研究了合金的结构,LaMn2Ge2在常温下具有ThCr2Si2-型晶体结构,空间群为I4/mmm.利用振动样品磁强计测量合金的磁性能,根据升降温的磁化曲线所确定的合金发生反铁磁-铁磁相变温度有4.3 K的滞后,居里温度约320 K,具有一级相变的典型特征.通过不同温度的磁化曲线结果,计算得LaMn2Ge2在1.43×106A/m外场变化下居里温度附近的最大磁熵变为1.42 J/kg·K.
用非自耗真空电弧炉制备LaMn2Ge2合金,采用X射线衍射研究了合金的结构,LaMn2Ge2在常温下具有ThCr2Si2-型晶体结构,空间群为I4/mmm.利用振动样品磁强计测量合金的磁性能,根据升降温的磁化曲线所确定的合金发生反铁磁-铁磁相变温度有4.3 K的滞后,居里温度约320 K,具有一级相变的典型特征.通过不同温度的磁化曲线结果,计算得LaMn2Ge2在1.43×106A/m外场变化下居里温度附近的最大磁熵变为1.42 J/kg·K.
Li Xintao
,
Li Tingju
,
Zhang Xingguo
,
Zhou Wenlong
,
Yin Guomao
,
Tan Jianchang
,
Zheng Long
,
Song Ruili
,
Gao Linhan
2006, 35(11):1806-1808.
Abstract:
探索了用水平连铸的方法制备BFe30-1-1铜合金空心管坯的技术,在实验室成功制备了φ83mm×20mm空心管坯。对管坯的表面质量,凝固组织及力学性能进行了分析。结果表明,采用合适的熔铸工艺参数,可以用水平连铸的方法制备BFe30-1-1铜合金空心管坯。
探索了用水平连铸的方法制备BFe30-1-1铜合金空心管坯的技术,在实验室成功制备了φ83mm×20mm空心管坯。对管坯的表面质量,凝固组织及力学性能进行了分析。结果表明,采用合适的熔铸工艺参数,可以用水平连铸的方法制备BFe30-1-1铜合金空心管坯。
2006, 35(11):1809-1812.
Abstract:
采用熔体快淬及退火方法制备了Nd10.1Fe(82.2-x)Co5Zr2.7Bx(x=6.2,6.5,6.7,7)纳米晶双相永磁体.结果表明,优化B的含量,可使晶粒细化、均匀,并对其磁性能有一定的影响,在x=6.7时,快淬速度为16m·s-1,有显著的剩磁增强作用,各向同性剩磁比Mr/Ms=0.758,并且Nd10.1Fe(82.2-x)C05Zr2.7Bx粘结磁体出现最佳性能,其剩磁和最大磁能积分别为Br=0.72 T,(BH)max=85.0 kJ·m-3.
采用熔体快淬及退火方法制备了Nd10.1Fe(82.2-x)Co5Zr2.7Bx(x=6.2,6.5,6.7,7)纳米晶双相永磁体.结果表明,优化B的含量,可使晶粒细化、均匀,并对其磁性能有一定的影响,在x=6.7时,快淬速度为16m·s-1,有显著的剩磁增强作用,各向同性剩磁比Mr/Ms=0.758,并且Nd10.1Fe(82.2-x)C05Zr2.7Bx粘结磁体出现最佳性能,其剩磁和最大磁能积分别为Br=0.72 T,(BH)max=85.0 kJ·m-3.
2006, 35(11):1813-1816.
Abstract:
研究了以AM50镁合金为基体，Si含量分别为0．5％，0．93％和1．91％（质量分数，下同）时的3种镁合金在压铸状态下的显微组织、流动性、力学性能和断裂特征。在含硅合金中观察到Mg2Si相的2种不同形貌，即多边形颗粒状与大块汉字状。Si元素能改善镁合金的流动性，提高合金硬度，但过高时（〉0．93％）会导致合金的室温力学性能下降。拉伸试样断面表现为脆性的解理或准解理断裂。Si元素能降低镁合金的冲击韧性。
研究了以AM50镁合金为基体，Si含量分别为0．5％，0．93％和1．91％（质量分数，下同）时的3种镁合金在压铸状态下的显微组织、流动性、力学性能和断裂特征。在含硅合金中观察到Mg2Si相的2种不同形貌，即多边形颗粒状与大块汉字状。Si元素能改善镁合金的流动性，提高合金硬度，但过高时（〉0．93％）会导致合金的室温力学性能下降。拉伸试样断面表现为脆性的解理或准解理断裂。Si元素能降低镁合金的冲击韧性。
2006, 35(11):1817-1821.
Abstract:
针对TC4钛合金锻件误加工造成的铣槽和面尺寸超差进行了激光快速修复研究。修复区与锻件基体之间形成致密冶金结合，修复区组织为柱状原始声晶界内编织细密的α＋β网篮组织，晶内α板条的宽度〈1μm。修复过程中发现粉末状况、激光加工参数影响到修复区中气孔、层间或道间熔合不良等缺陷的形成，通过采用粉末真空干燥处理、优化工艺参数等方法获得了修复区内无气孔、熔合不良等缺陷的修复试样。修复试样的室温静载拉伸性能测试结果表明，其抗拉强度达到1000MPa，屈服强度达到925MPa，延伸率为8．0％，接近锻件本体性能。
针对TC4钛合金锻件误加工造成的铣槽和面尺寸超差进行了激光快速修复研究。修复区与锻件基体之间形成致密冶金结合，修复区组织为柱状原始声晶界内编织细密的α＋β网篮组织，晶内α板条的宽度〈1μm。修复过程中发现粉末状况、激光加工参数影响到修复区中气孔、层间或道间熔合不良等缺陷的形成，通过采用粉末真空干燥处理、优化工艺参数等方法获得了修复区内无气孔、熔合不良等缺陷的修复试样。修复试样的室温静载拉伸性能测试结果表明，其抗拉强度达到1000MPa，屈服强度达到925MPa，延伸率为8．0％，接近锻件本体性能。
2006, 35(11):1822-1825.
Abstract:
The microstructures and impact toughness of thermal simulated welding HAZ in 2205 duplex stainless steel were studied by means of thermal simulator and impact testing in the paper. The influences of cooling time on the impact toughness of thermal simulated HAZ were investigated also. The results show that the cooling time has strong effects on the impact toughness of the thermal simulated HAZ, that the ferrite content and micro hardness decreases as increasing of cooling time, that the microhardness in ferrite is lower than that than in austenite, that impact toughness increases with the increase of the cooling time t12/8 for a certain cooling time t8/5, and that impact toughness decreases with the increase of the cooling time t8/5 for a certain cooling time t12/8.
The microstructures and impact toughness of thermal simulated welding HAZ in 2205 duplex stainless steel were studied by means of thermal simulator and impact testing in the paper. The influences of cooling time on the impact toughness of thermal simulated HAZ were investigated also. The results show that the cooling time has strong effects on the impact toughness of the thermal simulated HAZ, that the ferrite content and micro hardness decreases as increasing of cooling time, that the microhardness in ferrite is lower than that than in austenite, that impact toughness increases with the increase of the cooling time t12/8 for a certain cooling time t8/5, and that impact toughness decreases with the increase of the cooling time t8/5 for a certain cooling time t12/8.
2006, 35(11):1826-1829.
Abstract:
利用双层辉光等离子表面冶金技术对Ti2AlNbO相合金进行渗Mo工艺研究。采用扫描电子显微镜、辉光放电光谱分析仪、X射线衍射仪和显微硬度计测试了渗Mo层的微观组织、化学成分、相组成和显微硬度。采用可控气氛微型摩擦磨损实验仪进行耐磨性研究。在最佳工艺参数下，渗Mo层可达100μm，表面Mo含量超过90％，且从表面到心部呈梯度分布。渗Mo层主要由纯Mo及Al5Mo相组成，硬度HV达8000MPa，渗Mo试样的平均摩擦因数为0．085，较Ti2AlNb基材降低6倍，磨损率仅为基材的7．5％。结果表明：Ti2AlNbO相合金表面的耐磨性能得到极大地提高。
利用双层辉光等离子表面冶金技术对Ti2AlNbO相合金进行渗Mo工艺研究。采用扫描电子显微镜、辉光放电光谱分析仪、X射线衍射仪和显微硬度计测试了渗Mo层的微观组织、化学成分、相组成和显微硬度。采用可控气氛微型摩擦磨损实验仪进行耐磨性研究。在最佳工艺参数下，渗Mo层可达100μm，表面Mo含量超过90％，且从表面到心部呈梯度分布。渗Mo层主要由纯Mo及Al5Mo相组成，硬度HV达8000MPa，渗Mo试样的平均摩擦因数为0．085，较Ti2AlNb基材降低6倍，磨损率仅为基材的7．5％。结果表明：Ti2AlNbO相合金表面的耐磨性能得到极大地提高。
2006, 35(11):1830-1834.
Abstract:
研究了3种不同含Ti量单晶高温合金的铸态、热处理态组织及持久性能。结果表明：Ti含量对合金的微观组织和持久性能都有明显的影响。随着钛含量的增加，铸态合金枝晶间区域的共晶尺寸和含量明显增大、增多，枝晶间区域的面积也逐渐增大。热处理后，3种合金的枝晶干处的γ′相形态基本一致，都为规则的立方体γ′相，尺寸大约为400nm-500nm。随着钛含量的增加，合金的持久寿命略有降低，延伸率略有增加。
研究了3种不同含Ti量单晶高温合金的铸态、热处理态组织及持久性能。结果表明：Ti含量对合金的微观组织和持久性能都有明显的影响。随着钛含量的增加，铸态合金枝晶间区域的共晶尺寸和含量明显增大、增多，枝晶间区域的面积也逐渐增大。热处理后，3种合金的枝晶干处的γ′相形态基本一致，都为规则的立方体γ′相，尺寸大约为400nm-500nm。随着钛含量的增加，合金的持久寿命略有降低，延伸率略有增加。
2006, 35(11):1835-1837.
Abstract:
通过XRD分析了Sm2Fe17合金的氮化行为及该过程中合金的结构演变规律.结果表明Sm2Fe17合金粉末在460℃～510℃氮化5 h的过程中,随着氮化温度的升高,合金的晶格常数、体积膨胀量不断增加,预示着合金中氮含量的增加,490℃时角度偏移量最大达到约0.9°,晶胞体积膨胀量达6.568%,合金中的氮含量达到最大值;500℃以后氮化物的分解占主导地位.同时,建立了Sm2Fe17合金粉末的氮化过程的物理模型.
通过XRD分析了Sm2Fe17合金的氮化行为及该过程中合金的结构演变规律.结果表明Sm2Fe17合金粉末在460℃～510℃氮化5 h的过程中,随着氮化温度的升高,合金的晶格常数、体积膨胀量不断增加,预示着合金中氮含量的增加,490℃时角度偏移量最大达到约0.9°,晶胞体积膨胀量达6.568%,合金中的氮含量达到最大值;500℃以后氮化物的分解占主导地位.同时,建立了Sm2Fe17合金粉末的氮化过程的物理模型.
2006, 35(11):1838-1840.
Abstract:
采用熔融法制备Bi100-xSbx热电材料,并在550K经过500 h的恒温加热.用SEM分析了材料的微观形貌,在80 K～300K温度范围内测试了材料的电阻率、Seebeck系数、热导率随温度的变化,讨论了材料优质系数随温度的变化关系.x=13的样品在80 K优质系数达到4.3×10-3K-1.
采用熔融法制备Bi100-xSbx热电材料,并在550K经过500 h的恒温加热.用SEM分析了材料的微观形貌,在80 K～300K温度范围内测试了材料的电阻率、Seebeck系数、热导率随温度的变化,讨论了材料优质系数随温度的变化关系.x=13的样品在80 K优质系数达到4.3×10-3K-1.
2006, 35(11):1841-1844.
Abstract:
The progress has been made in the area of extending photocatalytic performance of TiO2 by doping in different methods, which makes titanic the promising material for its application in decomposing contamination of atmosphere and water. The modification methods, including metal cation doping, metalloid anion doping, compound anion doping etc, are dealt with in this review.
The progress has been made in the area of extending photocatalytic performance of TiO2 by doping in different methods, which makes titanic the promising material for its application in decomposing contamination of atmosphere and water. The modification methods, including metal cation doping, metalloid anion doping, compound anion doping etc, are dealt with in this review.
2006, 35(11):1845-18471848.
Abstract:
In this paper, progress in research of TiAl matrix composites at home and abroad was reviewed. The mechanical properties of some typical long fibers, short fibers, whiskers and particles reinforced TiAl matrix composites were summarized. Various technologies and features for preparing TiAl matrix composites were discussed especially.
In this paper, progress in research of TiAl matrix composites at home and abroad was reviewed. The mechanical properties of some typical long fibers, short fibers, whiskers and particles reinforced TiAl matrix composites were summarized. Various technologies and features for preparing TiAl matrix composites were discussed especially.
