Volume 33,Issue 5,2004 Table of Contents
2004, 33(5):449-453.
Abstract:
Technological methods of preparing indium tin oxide(ITO) powder and ITO sputtering target are summarized and some remark on them are made in this paper. The various preparing procedures and the principles of the technology methods are recommend and analyzed. Relative merits of these methods are investigated, furthermore, ideas of improvement on preparing good quality ITO powder and the target are proposed.
Technological methods of preparing indium tin oxide(ITO) powder and ITO sputtering target are summarized and some remark on them are made in this paper. The various preparing procedures and the principles of the technology methods are recommend and analyzed. Relative merits of these methods are investigated, furthermore, ideas of improvement on preparing good quality ITO powder and the target are proposed.
2004, 33(5):454-458.
Abstract:
The distribution of major elements Co, Mo, Mn, Gr etc and trace elements Al, Ti, Ce, La etc and the effects of their compounds on properties of high density alloy were analyzed respectively. The effects of elements in alloy are refining grains, strengthening binder, strengthening tungsten grains, increasing the interface bonding, improving wetting power between binder and tungsten grains and affecting the distribution and morphology of impurities. The distribution characteristics of impurities and their compounds on boundaries were reviewed. Phorsphor which segregates on the boundaries with free state or compounds results in the fragility of the alloy and increasing the sintering activation ability. Hydrogen will also results in fragility by decrease the bonding strength of interface. Minor carbon will decrease the segregation of P, but with increasing carbon content, the dynamic tensile strength of alloy will decrease.
The distribution of major elements Co, Mo, Mn, Gr etc and trace elements Al, Ti, Ce, La etc and the effects of their compounds on properties of high density alloy were analyzed respectively. The effects of elements in alloy are refining grains, strengthening binder, strengthening tungsten grains, increasing the interface bonding, improving wetting power between binder and tungsten grains and affecting the distribution and morphology of impurities. The distribution characteristics of impurities and their compounds on boundaries were reviewed. Phorsphor which segregates on the boundaries with free state or compounds results in the fragility of the alloy and increasing the sintering activation ability. Hydrogen will also results in fragility by decrease the bonding strength of interface. Minor carbon will decrease the segregation of P, but with increasing carbon content, the dynamic tensile strength of alloy will decrease.
2004, 33(5):459-463.
Abstract:
Forming conditions, control factors, alloy design methods, manufacturing principle and technology of bulk amorphous alloys are analyzed and discussed using nucleation theory. The complete and necessary conditions of bulk amorphous alloy formation are preventing inhomogeneous nucleation and restraining homogeneous nucleation. The former can be realized by controlling effectively exterior melting conditions including purification, optimum cooling medium and inert atmosphere protection, et al. The latter can be achieved by the reasonable alloy design that involve multi-components, high ratio of atom radius, large negative blending heat, composition with low melting point or low eutectic point.
Forming conditions, control factors, alloy design methods, manufacturing principle and technology of bulk amorphous alloys are analyzed and discussed using nucleation theory. The complete and necessary conditions of bulk amorphous alloy formation are preventing inhomogeneous nucleation and restraining homogeneous nucleation. The former can be realized by controlling effectively exterior melting conditions including purification, optimum cooling medium and inert atmosphere protection, et al. The latter can be achieved by the reasonable alloy design that involve multi-components, high ratio of atom radius, large negative blending heat, composition with low melting point or low eutectic point.
2004, 33(5):468-472.
Abstract:
By hot swaging, the nanocomposite W-4.5%ThO2 cathode was fabricated. A comparative study on the anti-erosion ability for a conventional W-2%ThO2, W-4.5%ThO2 cathode and a nanocomposite W-4.5%ThO2 cathode has been made by using gas-tungsten arc (GTA) welding. The results indicated that the relative density of the nanocomposite material is near full. The microstructure of the nanocomposite cathode is quite different from that of conventional thoriated tungsten cathodes. Most of the thoria particles in the nanocomposite are less than 200 nm in diameter, and situated on the tungsten grain boundaries. The arc starting characteristic of the nanocomposite W-4.5%ThO2 electrode is the best among the three cathodes. The cathode tip shape after arc burning was obseved. The results show that the anti-erosion ability of the nanocomposite W-4.5%ThO2 cathode had been obviously improved, which indicated that the cathode characteristics depend mainly on the content and partcle size of thoria.
By hot swaging, the nanocomposite W-4.5%ThO2 cathode was fabricated. A comparative study on the anti-erosion ability for a conventional W-2%ThO2, W-4.5%ThO2 cathode and a nanocomposite W-4.5%ThO2 cathode has been made by using gas-tungsten arc (GTA) welding. The results indicated that the relative density of the nanocomposite material is near full. The microstructure of the nanocomposite cathode is quite different from that of conventional thoriated tungsten cathodes. Most of the thoria particles in the nanocomposite are less than 200 nm in diameter, and situated on the tungsten grain boundaries. The arc starting characteristic of the nanocomposite W-4.5%ThO2 electrode is the best among the three cathodes. The cathode tip shape after arc burning was obseved. The results show that the anti-erosion ability of the nanocomposite W-4.5%ThO2 cathode had been obviously improved, which indicated that the cathode characteristics depend mainly on the content and partcle size of thoria.
2004, 33(5):473-477.
Abstract:
Structural applications of foamed metals are increasingly growing, and their mechanical properties accordingly appears to be more and more important. Some structural applications are enumerated for these materials, the consciousness is strengthened to study on their mechanical behavior, and the necessity is put forward that the biaxial tensile properties dependence of porosity should be investigated more comprehensively.
Structural applications of foamed metals are increasingly growing, and their mechanical properties accordingly appears to be more and more important. Some structural applications are enumerated for these materials, the consciousness is strengthened to study on their mechanical behavior, and the necessity is put forward that the biaxial tensile properties dependence of porosity should be investigated more comprehensively.
2004, 33(5):478-481.
Abstract:
采用RF-PCVD法，以TiCl4 O2为反应体系，制备出纳米级的TiO2粉体。经TEM，XRD及粒度分布仪测试表明：粉体呈近球形，为锐钛矿型和金红石型的混晶体，粒径范围为15nm～45nm，团聚后，粒径≤116nm的粉体占90％，并对纳米粉体的形成、分布和晶型进行了初步探讨。苯酚降解实验表明，TiO2粉体具有明显的光催化活性。
采用RF-PCVD法，以TiCl4 O2为反应体系，制备出纳米级的TiO2粉体。经TEM，XRD及粒度分布仪测试表明：粉体呈近球形，为锐钛矿型和金红石型的混晶体，粒径范围为15nm～45nm，团聚后，粒径≤116nm的粉体占90％，并对纳米粉体的形成、分布和晶型进行了初步探讨。苯酚降解实验表明，TiO2粉体具有明显的光催化活性。
2004, 33(5):482-484.
Abstract:
Described a novel method for producing high purity potassium silver cyanide [KAg (CN)2] that uses silver oxide [Ag2O] as an intermediate and crude silver as a silver source (surplus silver from silver nitrate production). To obtain high quality product, the evaporation of water from the KAg (CN)2 solution should be carefully controlled.
Described a novel method for producing high purity potassium silver cyanide [KAg (CN)2] that uses silver oxide [Ag2O] as an intermediate and crude silver as a silver source (surplus silver from silver nitrate production). To obtain high quality product, the evaporation of water from the KAg (CN)2 solution should be carefully controlled.
2004, 33(5):485-489.
Abstract:
The effect of Ca, Pd, Sn and La atoms substitution for the central Mg atom of magnesium hydride Mg(M)H2 atom cluster on electronic structure and bonding characterization have been studied by using the discrete variational method (DVM) based on the first principles. The crystal orbital overlap population (COOP), the bond order (BO) and the bonding charge densities were analyzed by calculation. It showed that the substitution atoms Ca, Pd, Sn and La had an obvious effect on the chemical bond Mg-H which corresponds to the stable of Mg(M)H2 structure. The charge densities around their nearest neighbor Mg are redistributed and obviously anisotropic. When M is Ca, Pd or La, BO between the nearest neighbor Mg and H is almost same and increased slightly; when M is Sn, it is greatly decreased. The increased order is Sn < La < Pd < Ca. And the interactions between the other Mg atoms and hydrogen are also affected to some degree.
The effect of Ca, Pd, Sn and La atoms substitution for the central Mg atom of magnesium hydride Mg(M)H2 atom cluster on electronic structure and bonding characterization have been studied by using the discrete variational method (DVM) based on the first principles. The crystal orbital overlap population (COOP), the bond order (BO) and the bonding charge densities were analyzed by calculation. It showed that the substitution atoms Ca, Pd, Sn and La had an obvious effect on the chemical bond Mg-H which corresponds to the stable of Mg(M)H2 structure. The charge densities around their nearest neighbor Mg are redistributed and obviously anisotropic. When M is Ca, Pd or La, BO between the nearest neighbor Mg and H is almost same and increased slightly; when M is Sn, it is greatly decreased. The increased order is Sn < La < Pd < Ca. And the interactions between the other Mg atoms and hydrogen are also affected to some degree.
2004, 33(5):490-493.
Abstract:
A new technology for preparation of TaC coating on C/C composite material is reported. The ethylate tantalum film is characterized by FT-IR spectra, XRD and SEM, and the TaC coating is characterized by XRD and SEM. The amorphous ethylate tantalum jellied is prepared and is spreaded out densely on the surface of C/C composite material to form a multi-films. In the graphite furnace the multi-films is transformed into the TaC coatings at various temperatures. At 1 200C the coating contains TaC and Ta2O5,and at above 1 400C only TaC exists. The structure of the coating at 1 600C is a continuous dense stratum structure, and at 1 400C is a porous net structure.
A new technology for preparation of TaC coating on C/C composite material is reported. The ethylate tantalum film is characterized by FT-IR spectra, XRD and SEM, and the TaC coating is characterized by XRD and SEM. The amorphous ethylate tantalum jellied is prepared and is spreaded out densely on the surface of C/C composite material to form a multi-films. In the graphite furnace the multi-films is transformed into the TaC coatings at various temperatures. At 1 200C the coating contains TaC and Ta2O5,and at above 1 400C only TaC exists. The structure of the coating at 1 600C is a continuous dense stratum structure, and at 1 400C is a porous net structure.
2004, 33(5):494-497.
Abstract:
The anode polarization curve of A0 pure aluminum in DI (de-ions) water was measured to simulate the pit corrosion of reactor pool shell. It confirmed the A0 aluminum is easy to passivate in DI water. The potential in the pit were determined with EG&G Princeton Applied Research Potentiostat/ Galvanostat Model 273, the polarization curve shows that the simulated corrosion pit was in passivated situation, even if the oxidization film was broken, the corrosion pit will probably develop slowly, the varied pH in pit was determined with pH measurer, and the working curves were obtained, which shows the obvious acidification exists in pit for the sample with oxidization film. The service life of A0 aluminum pool shell was estimated.
The anode polarization curve of A0 pure aluminum in DI (de-ions) water was measured to simulate the pit corrosion of reactor pool shell. It confirmed the A0 aluminum is easy to passivate in DI water. The potential in the pit were determined with EG&G Princeton Applied Research Potentiostat/ Galvanostat Model 273, the polarization curve shows that the simulated corrosion pit was in passivated situation, even if the oxidization film was broken, the corrosion pit will probably develop slowly, the varied pH in pit was determined with pH measurer, and the working curves were obtained, which shows the obvious acidification exists in pit for the sample with oxidization film. The service life of A0 aluminum pool shell was estimated.
2004, 33(5):502-506.
Abstract:
Ceramic oxide coatings were fabricated on a Ti6Al4V alloy surface by micro-arc oxidation (MAO) in Na2SiO3-KOH-(NaPO3)6-NaAlO2 solution using an AC power supply. Microstructure, phase and composition of ceramic coatings were characterized by SEM and XRD respectively. Mechanical properties were studied using a Nano Indenter XP system. The results show that ceramic coatings possess three layers transitional, dense and loose layer, composed mainly of rutile TiO2 and a small amount of anatase TiO2. Elastic recovery is 40.5% and 14.9%, hardness is 8.54 GPa and 5.5 GPa, and elastic modulus is 87.4 GPa and 150 GPa in the dense layer and the substrate, respectively, The MAO coating indicates pronounced ceramic characteristics.
Ceramic oxide coatings were fabricated on a Ti6Al4V alloy surface by micro-arc oxidation (MAO) in Na2SiO3-KOH-(NaPO3)6-NaAlO2 solution using an AC power supply. Microstructure, phase and composition of ceramic coatings were characterized by SEM and XRD respectively. Mechanical properties were studied using a Nano Indenter XP system. The results show that ceramic coatings possess three layers transitional, dense and loose layer, composed mainly of rutile TiO2 and a small amount of anatase TiO2. Elastic recovery is 40.5% and 14.9%, hardness is 8.54 GPa and 5.5 GPa, and elastic modulus is 87.4 GPa and 150 GPa in the dense layer and the substrate, respectively, The MAO coating indicates pronounced ceramic characteristics.
2004, 33(5):507-511.
Abstract:
用高能量密度脉冲等离子体于室温下在氮化硅陶瓷刀具上成功沉积了高硬耐磨的氮化钛涂层。薄膜厚度用光学显微镜和俄歇电子能谱仪测定，薄膜元素和相组成与分布分别用俄歇电子能谱仪、X光电子能谱以及X光衍射仪测定，薄膜微观结构用扫描电镜观察，薄膜表面粗糙度用光学显微镜测定，薄膜力学性能由纳米压痕实验和纳米划痕实验确定，薄膜的磨损性能用上业条件下的切削实验评价。实验结果表明，在最优化条件下，涂层与基体的结合力很好，纳米划痕实验临界载荷达80mN以上；氮化钛涂层具有很高的硬度和杨氏模量，分别达28GPa和350GPa以上。涂层刀具用于HB达2200MPa—2300MPa的HT250钢切削实验表明，刀具耐磨损能力增强，寿命明显提高。
用高能量密度脉冲等离子体于室温下在氮化硅陶瓷刀具上成功沉积了高硬耐磨的氮化钛涂层。薄膜厚度用光学显微镜和俄歇电子能谱仪测定，薄膜元素和相组成与分布分别用俄歇电子能谱仪、X光电子能谱以及X光衍射仪测定，薄膜微观结构用扫描电镜观察，薄膜表面粗糙度用光学显微镜测定，薄膜力学性能由纳米压痕实验和纳米划痕实验确定，薄膜的磨损性能用上业条件下的切削实验评价。实验结果表明，在最优化条件下，涂层与基体的结合力很好，纳米划痕实验临界载荷达80mN以上；氮化钛涂层具有很高的硬度和杨氏模量，分别达28GPa和350GPa以上。涂层刀具用于HB达2200MPa—2300MPa的HT250钢切削实验表明，刀具耐磨损能力增强，寿命明显提高。
2004, 33(5):512-514.
Abstract:
利用水冷铜模激光熔炼炉制得了由初生枝晶Cr3Si和枝晶间Cr3Si／Crl3Ni5Si2共晶组成的金属间化合物合金。利用OM，SEM，TEM，EDS和XRD分析了该金属间化合物的显微组织，在400℃，500℃和600℃条件下测试了其耐磨性能。结果表明，由于Cr3Si和Crl3NisSi2硬度高、原子键合力强、组织细小、均匀，在高温滑动磨损条件下具有优良的耐磨性能。
利用水冷铜模激光熔炼炉制得了由初生枝晶Cr3Si和枝晶间Cr3Si／Crl3Ni5Si2共晶组成的金属间化合物合金。利用OM，SEM，TEM，EDS和XRD分析了该金属间化合物的显微组织，在400℃，500℃和600℃条件下测试了其耐磨性能。结果表明，由于Cr3Si和Crl3NisSi2硬度高、原子键合力强、组织细小、均匀，在高温滑动磨损条件下具有优良的耐磨性能。
2004, 33(5):515-517.
Abstract:
用振动样品磁强计测量DyCo2化合物的磁化曲线,采用二元函数在矩形区域的双一次插值逼近拟合出M (T, H )的二元函数表达式,然后根据磁熵变的热力学公式,计算出它的磁熵变值。通过计算得到DyCo2合金的居里温度为142 K,在外磁场变化为1 T时,最大磁熵变为5.45 J/kg·K,因而DyCo2合金是良好的磁制冷材料。计算结果表明这种计算磁熵变的方法可行,能够得到比较准确的结果。
用振动样品磁强计测量DyCo2化合物的磁化曲线,采用二元函数在矩形区域的双一次插值逼近拟合出M (T, H )的二元函数表达式,然后根据磁熵变的热力学公式,计算出它的磁熵变值。通过计算得到DyCo2合金的居里温度为142 K,在外磁场变化为1 T时,最大磁熵变为5.45 J/kg·K,因而DyCo2合金是良好的磁制冷材料。计算结果表明这种计算磁熵变的方法可行,能够得到比较准确的结果。
Zhang Yumei
,
Zhao Yimin
,
Huang Ping
,
Han Yong
,
P. Bataillon-linez
,
H.F. Hildebrand
,
M. Traisnel
2004, 33(5):518-521.
Abstract:
In this study the micro-arc oxidized (MAO) and hydrothermally synthesized (MAO-HS) methods were used to modify the TiO2 layer of titanium. The surface characters and the effects on cell behavior, which included cell adhesion kinetics and cytoskeletal organizations were need to evaluate. The surface energy was examined by physicochemical methods. Biological assays were performed with the mouse osteoblastic cell line MC3T3-E1, cells were inoculated on the treated surface of the materials. The surface energy of MAO (50.6 mJ/m2) and MAO-HS (58.5 mJ/m2) was higher than titanium (39.6 mJ/m2 ). A significantly higher cell adhesion rate was observed on the MAO-HS surface than on the MAO and titanium surface. The cytoskeletal organizations were analyzed by actin and vinculin staining on all the samples after being cultured 2 hours. Modification of TiO2 layer on titanium surface has an influence on the surface characters and the cell behavior on the materials.
In this study the micro-arc oxidized (MAO) and hydrothermally synthesized (MAO-HS) methods were used to modify the TiO2 layer of titanium. The surface characters and the effects on cell behavior, which included cell adhesion kinetics and cytoskeletal organizations were need to evaluate. The surface energy was examined by physicochemical methods. Biological assays were performed with the mouse osteoblastic cell line MC3T3-E1, cells were inoculated on the treated surface of the materials. The surface energy of MAO (50.6 mJ/m2) and MAO-HS (58.5 mJ/m2) was higher than titanium (39.6 mJ/m2 ). A significantly higher cell adhesion rate was observed on the MAO-HS surface than on the MAO and titanium surface. The cytoskeletal organizations were analyzed by actin and vinculin staining on all the samples after being cultured 2 hours. Modification of TiO2 layer on titanium surface has an influence on the surface characters and the cell behavior on the materials.
2004, 33(5):522-525.
Abstract:
The La2/3Ca1/3Mn1-xCuxO3(x=0.04)samples with different grain size were prepared by sol-gel method. The x-ray diffraction proves that all the samples are single phase and Cu doping and different sintering temperature do not change the lattice structure. Resistance versus temperature shows that semiconductor-metal transition moves to low temperature along with grain size decreasing. The experiment show that intergrain magnetoresistance increase from 25% to 51% in 25 K and 0.4 T as grain size decrease. The result of experiment indicates that intergrain magnetoresistance effects are substantially improved by lower level Cu doping in La2/3Ca1/3MnO3 polycrystals synthesized at low temperature and by minimizing grain size.
The La2/3Ca1/3Mn1-xCuxO3(x=0.04)samples with different grain size were prepared by sol-gel method. The x-ray diffraction proves that all the samples are single phase and Cu doping and different sintering temperature do not change the lattice structure. Resistance versus temperature shows that semiconductor-metal transition moves to low temperature along with grain size decreasing. The experiment show that intergrain magnetoresistance increase from 25% to 51% in 25 K and 0.4 T as grain size decrease. The result of experiment indicates that intergrain magnetoresistance effects are substantially improved by lower level Cu doping in La2/3Ca1/3MnO3 polycrystals synthesized at low temperature and by minimizing grain size.
2004, 33(5):526-530.
Abstract:
The aqueous-gel-tape-casting process is a novel technique fabricating flat ceramic materials. Employing the mechanism of three dimensions net structure formed by polymerized organic monomers, the high strength green bodies are formed by the net structure and ceramics particle filling in it. In the present work the influence of the organic monomer concentration and pH value and the polymerizing temperature and the concentration of initiator and catalyst on polymerization of the nanosized 3Y-TZP slurries during the aqueous-gel-tape-casting process was investigated. The results show that the polymerizing rate of the organic monomers increases greatly with the increase of the concentration of organic monomer in slurries. To ensure the proper polymerizing time, the concentration of the organic monomer solution must be controlled in the range of 10wt%~40wt%. The polymerizing rate of the organic monomers changes evidently with the different pH values. The higher the pH value, the lower the polymerization rate. The proper pH value is between 9~10. The polymerizing rate of the organic monomers increases with the increase of the temperature. Exceeding 35oC the polymerizing rate of the organic monomers changes greatly. The proper polymerizing temperature is from 35oC to 45 oC. The polymerizing rate of the organic monomers increases evidently with the increase of the concentration of the initiator and the catalyst. For perfect forming properties the concentration of initiator should be controlled in the range of 10wt% to 40wt%, the concentration of catalyst is about 0.20vol %.
The aqueous-gel-tape-casting process is a novel technique fabricating flat ceramic materials. Employing the mechanism of three dimensions net structure formed by polymerized organic monomers, the high strength green bodies are formed by the net structure and ceramics particle filling in it. In the present work the influence of the organic monomer concentration and pH value and the polymerizing temperature and the concentration of initiator and catalyst on polymerization of the nanosized 3Y-TZP slurries during the aqueous-gel-tape-casting process was investigated. The results show that the polymerizing rate of the organic monomers increases greatly with the increase of the concentration of organic monomer in slurries. To ensure the proper polymerizing time, the concentration of the organic monomer solution must be controlled in the range of 10wt%~40wt%. The polymerizing rate of the organic monomers changes evidently with the different pH values. The higher the pH value, the lower the polymerization rate. The proper pH value is between 9~10. The polymerizing rate of the organic monomers increases with the increase of the temperature. Exceeding 35oC the polymerizing rate of the organic monomers changes greatly. The proper polymerizing temperature is from 35oC to 45 oC. The polymerizing rate of the organic monomers increases evidently with the increase of the concentration of the initiator and the catalyst. For perfect forming properties the concentration of initiator should be controlled in the range of 10wt% to 40wt%, the concentration of catalyst is about 0.20vol %.
2004, 33(5):531-533.
Abstract:
Bias voltage applied to the substrate holder during thin film deposition is frequently used for modifying the coating properties in magnetron sputtering process. In this work, we have studied the indentation properties of sputter deposited Cu thin films on single crystal Si substrates under different bias in an effort to understand the effect of bias on the indentation properties and microstructure of soft films on hard substrates. The bias voltage was varied in the range 40 V to 100 V. The deposited thin films were characterized by transmission electron microscope (TEM), X-ray diffraction (XRD) and nanoindentation technique. The results show that with the bias voltage increasing, the grain size and residual stress decrease, which induce the hardness of Cu thin film increasing and it reaches the maximum at 80 V and then it decreases. At the same time, the indentation size effect has great influence on the hardness with depth increases.
Bias voltage applied to the substrate holder during thin film deposition is frequently used for modifying the coating properties in magnetron sputtering process. In this work, we have studied the indentation properties of sputter deposited Cu thin films on single crystal Si substrates under different bias in an effort to understand the effect of bias on the indentation properties and microstructure of soft films on hard substrates. The bias voltage was varied in the range 40 V to 100 V. The deposited thin films were characterized by transmission electron microscope (TEM), X-ray diffraction (XRD) and nanoindentation technique. The results show that with the bias voltage increasing, the grain size and residual stress decrease, which induce the hardness of Cu thin film increasing and it reaches the maximum at 80 V and then it decreases. At the same time, the indentation size effect has great influence on the hardness with depth increases.
2004, 33(5):534-538.
Abstract:
The effects of silane KH570 and stearic acid on ceramic injection molding for different stages were studied and analyzed in this article. Results show that stearic acid can play an effective part in reducing viscosity of as-received Si3N4 powder system and silane KH570 can play an important part in oxidized Si3N4 powder system. Debinding value was not affected by surfactants and its dosages, but the density and hardness of sintering body were reduced with the increasing of surfactants content. Density and hardness of sintering body could be improved when solvent debinding process was applied.
The effects of silane KH570 and stearic acid on ceramic injection molding for different stages were studied and analyzed in this article. Results show that stearic acid can play an effective part in reducing viscosity of as-received Si3N4 powder system and silane KH570 can play an important part in oxidized Si3N4 powder system. Debinding value was not affected by surfactants and its dosages, but the density and hardness of sintering body were reduced with the increasing of surfactants content. Density and hardness of sintering body could be improved when solvent debinding process was applied.
2004, 33(5):539-542.
Abstract:
主要研究了热摸锻时坯料变形温度、变形量对Ti-1023合金显微组织和拉伸性能的影响。研究结果表明：变形量不同，热摸锻坯料变形温度对合金拉伸强度影响不同。在经过30％变形后合金的抗拉强度随着变形温度的升高而增加，断面收缩率随变形温度升高先增加后下降，延伸率设有明显变化；而经过50%变形后，除了合金的抗拉强度随着温度升高而略有下降外，其余性能与合金经过30%变形后的变化趋势相同。在两相区(T-30℃)变彤时合金的拉伸性能随着变形量的增加先降低后增加，断裂韧性则相反；在β区(Tβ 30℃)变形时合金的抗拉强度随着变形量的增加先增加后降低，屈服强度没有明显变化，而塑性则随着变形量的增加而增加。
主要研究了热摸锻时坯料变形温度、变形量对Ti-1023合金显微组织和拉伸性能的影响。研究结果表明：变形量不同，热摸锻坯料变形温度对合金拉伸强度影响不同。在经过30％变形后合金的抗拉强度随着变形温度的升高而增加，断面收缩率随变形温度升高先增加后下降，延伸率设有明显变化；而经过50%变形后，除了合金的抗拉强度随着温度升高而略有下降外，其余性能与合金经过30%变形后的变化趋势相同。在两相区(T-30℃)变彤时合金的拉伸性能随着变形量的增加先降低后增加，断裂韧性则相反；在β区(Tβ 30℃)变形时合金的抗拉强度随着变形量的增加先增加后降低，屈服强度没有明显变化，而塑性则随着变形量的增加而增加。
2004, 33(5):548-551.
Abstract:
Amorphous Mg2Ni-based alloy powder was prepared by sintering and subsequent ball milling with Ni. The effects of substitution of Mn for Mg on phase formation and electrochemical discharge performance of Mg2Ni-typed alloys were studied. The results show that partial substitution of Mn for Mg in Mg2-xMnxNi (x=0.1,0.2,0.3,0.4) alloys can obtain homogeneous amorphous alloys and can increase the discharge capacity effectively compared with Mg2Ni alloy. As the content of Mn substitution increases, the maximum discharge capacity and rate discharge capability of Mg2Ni-typed alloy decline and the cycling durability upgrades.
Amorphous Mg2Ni-based alloy powder was prepared by sintering and subsequent ball milling with Ni. The effects of substitution of Mn for Mg on phase formation and electrochemical discharge performance of Mg2Ni-typed alloys were studied. The results show that partial substitution of Mn for Mg in Mg2-xMnxNi (x=0.1,0.2,0.3,0.4) alloys can obtain homogeneous amorphous alloys and can increase the discharge capacity effectively compared with Mg2Ni alloy. As the content of Mn substitution increases, the maximum discharge capacity and rate discharge capability of Mg2Ni-typed alloy decline and the cycling durability upgrades.
2004, 33(5):552-554.
Abstract:
The sensitive composite material was prepared by doping Pd and some metal oxides into ultrafine In2O3 matric material(8 nm) prepared by microemulsion method. A kind of selective C2H5OH gas sensor was developed based on a hot wire type gas sensor commercially available. The sensor possesses low power consumption , high selectivity and desirable long term stability. The dependence of the sensor output characteristics on temperature and humidity was also studied, and the working mechanism was discussed.
The sensitive composite material was prepared by doping Pd and some metal oxides into ultrafine In2O3 matric material(8 nm) prepared by microemulsion method. A kind of selective C2H5OH gas sensor was developed based on a hot wire type gas sensor commercially available. The sensor possesses low power consumption , high selectivity and desirable long term stability. The dependence of the sensor output characteristics on temperature and humidity was also studied, and the working mechanism was discussed.
2004, 33(5):555-557.
Abstract:
Ag/diamond contacts alloys with a nanoscaled microstructure of diamond particles was fabricated by high-energy ball milling, hot-pressing and sintering. Morphology and performance of the alloys were studied. The results show that the nanoscaled diamond particle dispersed inside Ag grains homogeneously. The morphological and crystal structure of diamond has no change after the prepare process. The density of hot-pressed block is more than 94% of the theory density. Different contents of diamond can lead to a hardness variant of the Ag/diamond alloy.
Ag/diamond contacts alloys with a nanoscaled microstructure of diamond particles was fabricated by high-energy ball milling, hot-pressing and sintering. Morphology and performance of the alloys were studied. The results show that the nanoscaled diamond particle dispersed inside Ag grains homogeneously. The morphological and crystal structure of diamond has no change after the prepare process. The density of hot-pressed block is more than 94% of the theory density. Different contents of diamond can lead to a hardness variant of the Ag/diamond alloy.
2004, 33(5):558-560.
Abstract:
在液相联氨还原法工艺基础上，对液相还原法制备纳米银粉的还原反应条件（体系温度、分散剂、反应物浓度）进行了研究，得到了优化的反应条件；反应体系温度70℃，反应物浓度[Ag[NH3]2^ ]=0.02mol/l和特定的分散剂2^#。且冬季同平均粒径约为50nm、大小均匀、灰白色的球状银粉。
在液相联氨还原法工艺基础上，对液相还原法制备纳米银粉的还原反应条件（体系温度、分散剂、反应物浓度）进行了研究，得到了优化的反应条件；反应体系温度70℃，反应物浓度[Ag[NH3]2^ ]=0.02mol/l和特定的分散剂2^#。且冬季同平均粒径约为50nm、大小均匀、灰白色的球状银粉。
