Volume 33,Issue 3,2004 Table of Contents
2004, 33(3):225-228.
Abstract:
The fluorescence character of the Eu2+ as a kind of activator in the alkaline earth aluminates and the effect factors on the phosphorescent properties were discussed. The methods of preparing long afterglow phosphors based on aluminates and the mechanism were analyzed, and finally the application fields were also introduced.
The fluorescence character of the Eu2+ as a kind of activator in the alkaline earth aluminates and the effect factors on the phosphorescent properties were discussed. The methods of preparing long afterglow phosphors based on aluminates and the mechanism were analyzed, and finally the application fields were also introduced.
2004, 33(3):229-233.
Abstract:
Flux pinning mechanism in superconducting NbTi composites with Ti5wt%Nb artificial pinning center is analyzed in detail. The results show that Fp(B) mainly depends on normal metal pinning mechanism and Dk pinning mechanism. The results suggeste that both normal metal pinning mechanism and Dk pinning mechanism are very important. The value of Fp(B) in lower magnetic field is mainly dominated by normal metal pinning mechanism and the value of Fp(B) in higher magnetic field is mainly dominated by Dk pinning mechanism. The function value of Fp(B) dependant on normal metal pinning mechanism and Dk pinning mechanism increase respectively with the decrease of the wire diameter.
Flux pinning mechanism in superconducting NbTi composites with Ti5wt%Nb artificial pinning center is analyzed in detail. The results show that Fp(B) mainly depends on normal metal pinning mechanism and Dk pinning mechanism. The results suggeste that both normal metal pinning mechanism and Dk pinning mechanism are very important. The value of Fp(B) in lower magnetic field is mainly dominated by normal metal pinning mechanism and the value of Fp(B) in higher magnetic field is mainly dominated by Dk pinning mechanism. The function value of Fp(B) dependant on normal metal pinning mechanism and Dk pinning mechanism increase respectively with the decrease of the wire diameter.
2004, 33(3):234-238.
Abstract:
The microscopic lattice kinetic model of aging process was build, using the coupling of the theory of microscopic elastic energy and microscopic diffusion equation. Taking a binary cubic model alloy with 14% (solute atom percent) as a example, the coarsening behavior of coherent precipitants was simulated. The results show that the main precipitation mechanism is nucleation and growth, while transient spinodal decomposition can also occur; In the presence of coherent mismatch, plate-like precipitants are formed, and tend to align along the elastically soft directions. During its coarsening process, particles lying in the soft directions grow and coarsen further, particles lying out of the soft directions dwindle. The coarsening process of the particles sitting in the same row or column obey that smaller particles shrink and larger ones grow.
The microscopic lattice kinetic model of aging process was build, using the coupling of the theory of microscopic elastic energy and microscopic diffusion equation. Taking a binary cubic model alloy with 14% (solute atom percent) as a example, the coarsening behavior of coherent precipitants was simulated. The results show that the main precipitation mechanism is nucleation and growth, while transient spinodal decomposition can also occur; In the presence of coherent mismatch, plate-like precipitants are formed, and tend to align along the elastically soft directions. During its coarsening process, particles lying in the soft directions grow and coarsen further, particles lying out of the soft directions dwindle. The coarsening process of the particles sitting in the same row or column obey that smaller particles shrink and larger ones grow.
2004, 33(3):239-241.
Abstract:
After the crystal structure of LaNi5 being analyzed, it has been included that there may be three twelve-face polyhedrons, nine octahedrons, six hexahedrons and thirty six tetrahedrons in an unit cell of LaNi5. The interstice radii of tetrahedron is smaller than that of hydrogen atom, so the tetrahedrons can not storage hydrogen. Then there will be 18 hydrogen atoms that can be storaged in an unit cell. This means that the ratio of hydrogen atom to metal atom is H/M=1. The maximum hydrogen capacity of LaNi5 is 1.379%.
After the crystal structure of LaNi5 being analyzed, it has been included that there may be three twelve-face polyhedrons, nine octahedrons, six hexahedrons and thirty six tetrahedrons in an unit cell of LaNi5. The interstice radii of tetrahedron is smaller than that of hydrogen atom, so the tetrahedrons can not storage hydrogen. Then there will be 18 hydrogen atoms that can be storaged in an unit cell. This means that the ratio of hydrogen atom to metal atom is H/M=1. The maximum hydrogen capacity of LaNi5 is 1.379%.
2004, 33(3):242-245.
Abstract:
基于多元素靶溅射的Andersen-Sigmund关系式，在分析了大量的二、三元素合金溅射稳定态靶表面化学成分的变化之后，发现各元素之间表面结合能之比几乎与靶体化学成分无关。只要给各元素之间设定适当的表面结合能比，就可以很容易地计算出三元合金靶稳定态表面化学成分，至少对于用2keV氩离子轰击的Ag-Pd-Au三元合金靶系来说，其计算结果都与实验值一致。所分析的实验数据是在常温下取得的，所以可不考虑离子轰击诱发的Gibbs偏析，其结论很可能是多元合金靶溅射的一般规律。此外，由Gaidikas等最近所提出的所谓择优溅射中的“基体效应”理论是无实验依据的。
基于多元素靶溅射的Andersen-Sigmund关系式，在分析了大量的二、三元素合金溅射稳定态靶表面化学成分的变化之后，发现各元素之间表面结合能之比几乎与靶体化学成分无关。只要给各元素之间设定适当的表面结合能比，就可以很容易地计算出三元合金靶稳定态表面化学成分，至少对于用2keV氩离子轰击的Ag-Pd-Au三元合金靶系来说，其计算结果都与实验值一致。所分析的实验数据是在常温下取得的，所以可不考虑离子轰击诱发的Gibbs偏析，其结论很可能是多元合金靶溅射的一般规律。此外，由Gaidikas等最近所提出的所谓择优溅射中的“基体效应”理论是无实验依据的。
2004, 33(3):246-250.
Abstract:
The structures of Ti alloy melted by cold-Cu mold non-consumable-electrode arc furnace change from equiaxed structure in chill layer to columnar structure, dendritic structure and equiaxed structure along the radial direction in turn. Based on temperature epuation, the relation between temperature grads of liquid- solid interface and time, the relation between the ratio of temperature grads of liquid- solid interface to solidification velocity and time were established. Used these relations and liquid-solid interface stability dynamic, the structure change was explained. The hardness on different location were different, which can be explained by theory of plastic deformation combined with quantitative metallogenetic.
The structures of Ti alloy melted by cold-Cu mold non-consumable-electrode arc furnace change from equiaxed structure in chill layer to columnar structure, dendritic structure and equiaxed structure along the radial direction in turn. Based on temperature epuation, the relation between temperature grads of liquid- solid interface and time, the relation between the ratio of temperature grads of liquid- solid interface to solidification velocity and time were established. Used these relations and liquid-solid interface stability dynamic, the structure change was explained. The hardness on different location were different, which can be explained by theory of plastic deformation combined with quantitative metallogenetic.
2004, 33(3):251-253.
Abstract:
Vapor doping affects the PTCR effect in BaTiO3 ceramics distinctly. Doping B2O3 vapor in BaTiO3 results in the expanding of the grain lattice cell. Thus, boron interstitial may get into BaTiO3 grain lattice. The room temperature resistance of Y-BaTiO3 decreases and the PTCR effect increases distinctly through the doping of B2O3 vapor. Given the same sintering condition, doping with higher level of the vapor B2O3 source results in the higher PTCR effect. The interstitial boron ion and/or its complex can act as trap center and enhance the PTCR effect of the ceramics.
Vapor doping affects the PTCR effect in BaTiO3 ceramics distinctly. Doping B2O3 vapor in BaTiO3 results in the expanding of the grain lattice cell. Thus, boron interstitial may get into BaTiO3 grain lattice. The room temperature resistance of Y-BaTiO3 decreases and the PTCR effect increases distinctly through the doping of B2O3 vapor. Given the same sintering condition, doping with higher level of the vapor B2O3 source results in the higher PTCR effect. The interstitial boron ion and/or its complex can act as trap center and enhance the PTCR effect of the ceramics.
2004, 33(3):254-257.
Abstract:
Using DSC, TEM and compress test, the effect of deformation on martensitic transformation and microstructure of the Ni-Mn-Ga alloy has been investigated. The mechanism of increase of martensitic transformation hysteresis after optimum plastic deformation has been discussed by thermodynamics and kinetics of martensitic transformation. The results show that the martensitic transformation temperatures keep constant, but reverse transformation temperatures sharply increase with an increase of the pre-deformation strain. The increase of transformation hysteresis in the alloy is mainly due to the release of the elastic energy deposited at the boundary induced by the plastic deformation.
Using DSC, TEM and compress test, the effect of deformation on martensitic transformation and microstructure of the Ni-Mn-Ga alloy has been investigated. The mechanism of increase of martensitic transformation hysteresis after optimum plastic deformation has been discussed by thermodynamics and kinetics of martensitic transformation. The results show that the martensitic transformation temperatures keep constant, but reverse transformation temperatures sharply increase with an increase of the pre-deformation strain. The increase of transformation hysteresis in the alloy is mainly due to the release of the elastic energy deposited at the boundary induced by the plastic deformation.
2004, 33(3):258-261.
Abstract:
利用热重分析(TGA)测量了原位生成的TiC／Ti-6Al复合材料在600，700和800℃下经连续20h的氧化增重特性，利用SEM，EDS和XRD研究了复合材料经氧化试验后表面氧化层的结构，相组成及成分。结果表明，原位生成的Ti基复合材料在高温氧化时遵循抛物线规律在800℃时的氧化增重量远大于600℃和700℃时的，计算获得该复合材料的氧化激活能为255．7kJ／mol。研究发现经20h的600℃或700℃氧化形成的氧化物呈现不连续的岛屿状，主要成分为金红石型的Ti02，而在800℃氧化20h后，氧化物是均匀连续的致密膜，由TiO2，A12O3组成。该复合材料的氧化首先发生在TiC颗粒的表面上，而不是象均质Ti材料一样氧化在整个表面上均匀地发生。
利用热重分析(TGA)测量了原位生成的TiC／Ti-6Al复合材料在600，700和800℃下经连续20h的氧化增重特性，利用SEM，EDS和XRD研究了复合材料经氧化试验后表面氧化层的结构，相组成及成分。结果表明，原位生成的Ti基复合材料在高温氧化时遵循抛物线规律在800℃时的氧化增重量远大于600℃和700℃时的，计算获得该复合材料的氧化激活能为255．7kJ／mol。研究发现经20h的600℃或700℃氧化形成的氧化物呈现不连续的岛屿状，主要成分为金红石型的Ti02，而在800℃氧化20h后，氧化物是均匀连续的致密膜，由TiO2，A12O3组成。该复合材料的氧化首先发生在TiC颗粒的表面上，而不是象均质Ti材料一样氧化在整个表面上均匀地发生。
2004, 33(3):262-266.
Abstract:
The phase structures and the electrochemical properties of the TiV-based hydrogen storage electrode alloy Ti0.8Zr0.2V2.4 Mn0.48Cr0.72Ni0.9 after rapid solidification have been studied. It is found by XRD analysis that the alloy mainly consists of C14 Laves phase with hexagonal structure and V-based solid solution phase with BCC structure. The rapid solidification leads to the decrease in content of the C14 Laves phase in the alloy. Electrochemical analyses show that the rapid solidification reduces the maximum discharge capacity, increases the activation cycles, elevates the surface reaction resistance and worsens the kinetic properties of the alloy electrode. However, the cyclic stability of the alloy electrode is improved greatly after rapid solidification.
The phase structures and the electrochemical properties of the TiV-based hydrogen storage electrode alloy Ti0.8Zr0.2V2.4 Mn0.48Cr0.72Ni0.9 after rapid solidification have been studied. It is found by XRD analysis that the alloy mainly consists of C14 Laves phase with hexagonal structure and V-based solid solution phase with BCC structure. The rapid solidification leads to the decrease in content of the C14 Laves phase in the alloy. Electrochemical analyses show that the rapid solidification reduces the maximum discharge capacity, increases the activation cycles, elevates the surface reaction resistance and worsens the kinetic properties of the alloy electrode. However, the cyclic stability of the alloy electrode is improved greatly after rapid solidification.
Huang Fuxiang
,
Ma Jusheng
,
Geng Zhiting
,
Ning Honglong
,
H. G. Suzuki Guo Shumei
,
Yu Xuetao
,
Wang Tao
,
Li Hong
,
Li Xincheng
2004, 33(3):267-270.
Abstract:
研制了新型集成电路引线框架Cu-Cr-Zr系列合金，通过电导率、硬度、抗拉强度测试以及透射电镜观察，考察了微量合金元素La，Fe／Ti，Co／Ti元素以及时效工艺对合金性能的影响。结果表明：稀土元素La可以改善A合金(Cu-Cr-Zr-Zn)的硬度及导电率；加入Fe／Ti，Co／Ti元素，大大提高了合金的强度和硬度，并使其时效的强度及硬度峰值延后。在970℃固溶处理、70％冷变形及不同温度时效2h后，A合金(Cu-Cr-Zr-Zn)及B合金(Cu-Cr-Zr-Zn-La)在450℃时达到硬度和强度峰值，分别为HV1770MPa和525MPa及HV1840MPa和554MPa，电导率分别为78％和80％IACS；在970℃固溶处理，60％冷变形，500℃时效2h，50％冷变形及不同温度2次时效2h后，C合金(Cu-Cr-Zr-Zn-Fe-Ti-La)及D合金(Cu-Cr-Zr-Zn-Co-Ti-La)在450℃时达到硬度和强度峰值，分别为HV2120MPa，683MPa及HV2040MPa和651MPa，电导率分别为65％和70％IACS。
研制了新型集成电路引线框架Cu-Cr-Zr系列合金，通过电导率、硬度、抗拉强度测试以及透射电镜观察，考察了微量合金元素La，Fe／Ti，Co／Ti元素以及时效工艺对合金性能的影响。结果表明：稀土元素La可以改善A合金(Cu-Cr-Zr-Zn)的硬度及导电率；加入Fe／Ti，Co／Ti元素，大大提高了合金的强度和硬度，并使其时效的强度及硬度峰值延后。在970℃固溶处理、70％冷变形及不同温度时效2h后，A合金(Cu-Cr-Zr-Zn)及B合金(Cu-Cr-Zr-Zn-La)在450℃时达到硬度和强度峰值，分别为HV1770MPa和525MPa及HV1840MPa和554MPa，电导率分别为78％和80％IACS；在970℃固溶处理，60％冷变形，500℃时效2h，50％冷变形及不同温度2次时效2h后，C合金(Cu-Cr-Zr-Zn-Fe-Ti-La)及D合金(Cu-Cr-Zr-Zn-Co-Ti-La)在450℃时达到硬度和强度峰值，分别为HV2120MPa，683MPa及HV2040MPa和651MPa，电导率分别为65％和70％IACS。
2004, 33(3):271-274.
Abstract:
采用重铬酸钾法对Cu-Zn-Al形状记忆合金进行钝化。应用化学浸泡和电化学方法研究了钝化Cu-Zn-Al形状记忆合金在Tyrodes 人工体液中的耐蚀性能。俄歇电子能谱(AES)和X射线能谱(EDX)分析表明,钝化CuZnAl 形状记忆合金表面膜层主要由(CrCu)2O3 (CuZn)O xH2O的水合尖晶石氧化物组成,该膜层附着力良好、平整、均匀、呈彩虹色花纹。钝化改善和提高了CuZnAl 形状记忆合金在Tyrodes 人工体液中的耐蚀性能、化学稳定性和抗色变能力,这是由于钝化合金表面形成热力学稳定的阻碍膜层及其化学效应,有效地抑制了合金的脱锌腐蚀。
采用重铬酸钾法对Cu-Zn-Al形状记忆合金进行钝化。应用化学浸泡和电化学方法研究了钝化Cu-Zn-Al形状记忆合金在Tyrodes 人工体液中的耐蚀性能。俄歇电子能谱(AES)和X射线能谱(EDX)分析表明,钝化CuZnAl 形状记忆合金表面膜层主要由(CrCu)2O3 (CuZn)O xH2O的水合尖晶石氧化物组成,该膜层附着力良好、平整、均匀、呈彩虹色花纹。钝化改善和提高了CuZnAl 形状记忆合金在Tyrodes 人工体液中的耐蚀性能、化学稳定性和抗色变能力,这是由于钝化合金表面形成热力学稳定的阻碍膜层及其化学效应,有效地抑制了合金的脱锌腐蚀。
2004, 33(3):275-278.
Abstract:
采用悬浮熔炼和球磨方法制备了CoSb2合金粉末,并研究了它的电化学吸放锂性能.研究结果表明,具有marcasite结构的CoSb2 的首次可逆容量为263 mAh·g-1, 相应的体积比容量为2 130 mAh·cm-3.经过 15 个循环后,其可逆容量衰减到 123 mAh·g-1.在本实验中发现,把中间相微碳球(MCMB)加入到CoSb2 中不仅能改善其循环寿命,而且也能够明显提高其可逆容量.非原位XRD 测试的结果表明,虽然 marcasite 结构的CoSb2 本身并不能存储锂,但其结构破坏后形成的锑能与锂进行可逆的电化学反应.
采用悬浮熔炼和球磨方法制备了CoSb2合金粉末,并研究了它的电化学吸放锂性能.研究结果表明,具有marcasite结构的CoSb2 的首次可逆容量为263 mAh·g-1, 相应的体积比容量为2 130 mAh·cm-3.经过 15 个循环后,其可逆容量衰减到 123 mAh·g-1.在本实验中发现,把中间相微碳球(MCMB)加入到CoSb2 中不仅能改善其循环寿命,而且也能够明显提高其可逆容量.非原位XRD 测试的结果表明,虽然 marcasite 结构的CoSb2 本身并不能存储锂,但其结构破坏后形成的锑能与锂进行可逆的电化学反应.
2004, 33(3):279-284.
Abstract:
Rapidly solidified Al-2.5Ti-2.5Fe and Al-2.5Ti-2.5Fe-2.5Cr alloys were prepared by a melt spinning method. As-quenched and as-annealed microstructures were studied by transmission electron microscopy (TEM), X-ray diffractometry(XRD), EDS and HREM. The influence of the Cr element doping on the as-quenched and as-annealed microstructure and microhardness of rapidly solidified Al-Ti-Fe alloy was also studied.
Rapidly solidified Al-2.5Ti-2.5Fe and Al-2.5Ti-2.5Fe-2.5Cr alloys were prepared by a melt spinning method. As-quenched and as-annealed microstructures were studied by transmission electron microscopy (TEM), X-ray diffractometry(XRD), EDS and HREM. The influence of the Cr element doping on the as-quenched and as-annealed microstructure and microhardness of rapidly solidified Al-Ti-Fe alloy was also studied.
2004, 33(3):285-288.
Abstract:
The effect of alloy elements on the quasi-solid solidification behavior of Al-4.5Cu alloy has been studied. The results indicate that Si and La can reduce the hot cracking tendency of Al-4.5Cu; adding 2%Si to matrix, the releasement of crystallization enthalpies makes the recalescence very severe, so the alloy cracks and cant have high strength; Al4.5Cu3Si has a strong ability of compensation and its fracture stress is highest among the Al-Cu-Si alloys; adding of La can reduce the secondary dendrite arm spacing, and the hot cracking properties are improved obviously.
The effect of alloy elements on the quasi-solid solidification behavior of Al-4.5Cu alloy has been studied. The results indicate that Si and La can reduce the hot cracking tendency of Al-4.5Cu; adding 2%Si to matrix, the releasement of crystallization enthalpies makes the recalescence very severe, so the alloy cracks and cant have high strength; Al4.5Cu3Si has a strong ability of compensation and its fracture stress is highest among the Al-Cu-Si alloys; adding of La can reduce the secondary dendrite arm spacing, and the hot cracking properties are improved obviously.
2004, 33(3):289-292.
Abstract:
研究了大塑性变形-反应烧结TiAl合金的高温压缩屈服强度。结果表明：高能球磨显著改善了烧结TiAl合金的压缩性能，同时其压缩性能还取决于烧结工艺。球磨1h粉末挤压坯经1250℃烧结4h后，800℃时的压缩屈服强度最高，达到620MPa，且与其实温值相当：而经1250℃烧结不同时间的未球磨粉末烧结体，800℃时压缩屈服强度最高仅为485MPa。因此，采用大塑性变形-反应烧结工艺制备高性能TiAl合金是可行的。
研究了大塑性变形-反应烧结TiAl合金的高温压缩屈服强度。结果表明：高能球磨显著改善了烧结TiAl合金的压缩性能，同时其压缩性能还取决于烧结工艺。球磨1h粉末挤压坯经1250℃烧结4h后，800℃时的压缩屈服强度最高，达到620MPa，且与其实温值相当：而经1250℃烧结不同时间的未球磨粉末烧结体，800℃时压缩屈服强度最高仅为485MPa。因此，采用大塑性变形-反应烧结工艺制备高性能TiAl合金是可行的。
2004, 33(3):293-296.
Abstract:
采用Sol-gel法制备出气敏材料La0．68Pb0．32FeO3纳米粉体。该粉体材料具有正交钙钛矿结构，晶胞参数a=0．55562nm，b=0．55965nm，c=0．78185nm，晶胞体积v=0．2431nm^3，平均粒径约为20nm。用该粉体制成气敏元件，并测试了该粉体材料在乙醇、丙酮和汽油中的气敏特性，测试结果表明：相比空气而言，在乙醇气氛中的La0．68Pb0．32FeO3电导值升高，呈现出n．型半导体载流子的导电特性；在丙酮和汽油气氛中的La0．68Pb0．32FeO3的电导值降低，呈现出p-型半导体载流子的导电特性。该材料对乙醇具有极高的气敏灵敏性，在0．01％的乙醇气氛中，灵敏度可达51；在0．1％的乙醇气氛中，灵敏度高达522。最佳工作温度区间在180℃～220℃。La0．68Pb0．32FeO3对丙酮和汽油也具有一定的灵敏性，在0．05％丙酮气氛中的灵敏度为30，最佳工作温度区间在220℃～260℃在0．1％汽油气氛中的灵敏度为5．0。La0．68Pb0．32FeO3纳米粉体具有电子与空穴复合导电机制。
采用Sol-gel法制备出气敏材料La0．68Pb0．32FeO3纳米粉体。该粉体材料具有正交钙钛矿结构，晶胞参数a=0．55562nm，b=0．55965nm，c=0．78185nm，晶胞体积v=0．2431nm^3，平均粒径约为20nm。用该粉体制成气敏元件，并测试了该粉体材料在乙醇、丙酮和汽油中的气敏特性，测试结果表明：相比空气而言，在乙醇气氛中的La0．68Pb0．32FeO3电导值升高，呈现出n．型半导体载流子的导电特性；在丙酮和汽油气氛中的La0．68Pb0．32FeO3的电导值降低，呈现出p-型半导体载流子的导电特性。该材料对乙醇具有极高的气敏灵敏性，在0．01％的乙醇气氛中，灵敏度可达51；在0．1％的乙醇气氛中，灵敏度高达522。最佳工作温度区间在180℃～220℃。La0．68Pb0．32FeO3对丙酮和汽油也具有一定的灵敏性，在0．05％丙酮气氛中的灵敏度为30，最佳工作温度区间在220℃～260℃在0．1％汽油气氛中的灵敏度为5．0。La0．68Pb0．32FeO3纳米粉体具有电子与空穴复合导电机制。
2004, 33(3):297-299.
Abstract:
在NH4OH-(NH4)2CO3沉淀体系中用相转移分离法制备了La0.9Sr0.1Ga0.8Mg0.2O2.85(LSGM1020)固体电解质前驱体,并在较低的烧结温度得到了纯度较高,杂质含量低的电解质陶瓷.用XRD,Raman光谱,直流四电极,交流阻抗谱和扫描电镜分析了电解质的晶体结构,电化学性能和显微结构.XRD和Raman分析表明LSGM1020电解质具有菱方钙钛矿结构,800oC时测量得到的氧离子电导率达到0.12S?cm-1.SEM和交流阻抗分析表明,烧结体具有良好的微观结构.采用相转移分离法合成LSGM1020有利于降低烧结温度,改善电解质的性能.
在NH4OH-(NH4)2CO3沉淀体系中用相转移分离法制备了La0.9Sr0.1Ga0.8Mg0.2O2.85(LSGM1020)固体电解质前驱体,并在较低的烧结温度得到了纯度较高,杂质含量低的电解质陶瓷.用XRD,Raman光谱,直流四电极,交流阻抗谱和扫描电镜分析了电解质的晶体结构,电化学性能和显微结构.XRD和Raman分析表明LSGM1020电解质具有菱方钙钛矿结构,800oC时测量得到的氧离子电导率达到0.12S?cm-1.SEM和交流阻抗分析表明,烧结体具有良好的微观结构.采用相转移分离法合成LSGM1020有利于降低烧结温度,改善电解质的性能.
2004, 33(3):300-304.
Abstract:
A lot of experiments about the anodization of A0 pure aluminum in oxalic acid solution were carried out. The technology parameters were decided, including the anode current density, the oxidization time and the temperature of the electrolyte solution. During the anode oxidization of the pool shell, some special key technologies were solved, including the oxidization technology of large equipment, the technology of the treatment with layer by layer and sealing with thin plastic films, the selection of the power, the circular cooling of the electrolyte solution, etc. Treating the whole pool shell with such measures, the abilities of the corrosion-proof and protection were greatly improved. The nuclear reactor has run for 37 years (from 1964 to 2001), by now the oxidization film on the surface of the pool shell is still bright. It can confirm that treating of the whole pool shell is successful and necessary, which can provide the help and reference for building the same model nuclear reactors.
A lot of experiments about the anodization of A0 pure aluminum in oxalic acid solution were carried out. The technology parameters were decided, including the anode current density, the oxidization time and the temperature of the electrolyte solution. During the anode oxidization of the pool shell, some special key technologies were solved, including the oxidization technology of large equipment, the technology of the treatment with layer by layer and sealing with thin plastic films, the selection of the power, the circular cooling of the electrolyte solution, etc. Treating the whole pool shell with such measures, the abilities of the corrosion-proof and protection were greatly improved. The nuclear reactor has run for 37 years (from 1964 to 2001), by now the oxidization film on the surface of the pool shell is still bright. It can confirm that treating of the whole pool shell is successful and necessary, which can provide the help and reference for building the same model nuclear reactors.
20 Effects of Technology Parameters of Anodic Arc Discharged Plasma on Preparation of Ni Nanopowders
2004, 33(3):305-308.
Abstract:
In inert gas, pure Ni nanopowders were prepared by anodic arc discharged plasma method utilizing self-designed and fabricated experimental apparatus, and the influence of arc current and gas pressure on the production rate and particle size of metal nanopowders in the process was studied. The product was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and the corresponding electron diffraction (ED) to determine the morphology, crystal microstructure, the size and size distribution. The experiment results revealed that Ni nanopowders with particle size range from 20 nm to 100 nm can be obtained by using the suitable controlled experimental apparatus. The production rate and particle size increase with raising arc current or gas pressure when other factors are fixed. The crystal structure of Ni nanopowders is the same as the bulk materials, is fcc phase.
In inert gas, pure Ni nanopowders were prepared by anodic arc discharged plasma method utilizing self-designed and fabricated experimental apparatus, and the influence of arc current and gas pressure on the production rate and particle size of metal nanopowders in the process was studied. The product was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and the corresponding electron diffraction (ED) to determine the morphology, crystal microstructure, the size and size distribution. The experiment results revealed that Ni nanopowders with particle size range from 20 nm to 100 nm can be obtained by using the suitable controlled experimental apparatus. The production rate and particle size increase with raising arc current or gas pressure when other factors are fixed. The crystal structure of Ni nanopowders is the same as the bulk materials, is fcc phase.
2004, 33(3):309-312.
Abstract:
用直流反应磁控溅射法制备了玻璃基TiO2薄膜。溅射过程中，Ar气的分压保持在0．8SPa不变，而O2的分压在0．10Pa～0．6SPa之间变化：镀膜试样在400℃～550℃之间进行热处理。用扫描电镜(SEM)、透射电镜(TEM)和紫外．可见光谱仪研究了薄膜的表面形貌、薄膜沉积速率和光学带隙宽度。结果表明，随着氧气分压从0．10Pa增加到0．6SPa，薄膜沉积速率从4．4nm／min下降到2．2nm／min，光学带隙从3．67eV下降到3．59eV，薄膜表面呈现出均匀的纳米晶粒和纳米孔：550℃热处理有助于较致密薄膜形成纳米晶粒和纳米孔，并降低带隙宽度。
用直流反应磁控溅射法制备了玻璃基TiO2薄膜。溅射过程中，Ar气的分压保持在0．8SPa不变，而O2的分压在0．10Pa～0．6SPa之间变化：镀膜试样在400℃～550℃之间进行热处理。用扫描电镜(SEM)、透射电镜(TEM)和紫外．可见光谱仪研究了薄膜的表面形貌、薄膜沉积速率和光学带隙宽度。结果表明，随着氧气分压从0．10Pa增加到0．6SPa，薄膜沉积速率从4．4nm／min下降到2．2nm／min，光学带隙从3．67eV下降到3．59eV，薄膜表面呈现出均匀的纳米晶粒和纳米孔：550℃热处理有助于较致密薄膜形成纳米晶粒和纳米孔，并降低带隙宽度。
2004, 33(3):313-316.
Abstract:
A novel method for preparing biomimetic bioactive calcium phosphate coatings on the electric materials was put forward. In the method the functional groups containing calcium element were first grafted on the surface of the electric materials by sonoelectrochemical method. When the modified materials were dipped into supersaturated calcium phosphate solution for a period of time, the calcium phosphate crystal would grow on the surface. By this technology, bioactive OCP coating has been successfully prepared on carbon/carbon composites, and biomimetic activation was realized on bioinert carbon/carbon composites.
A novel method for preparing biomimetic bioactive calcium phosphate coatings on the electric materials was put forward. In the method the functional groups containing calcium element were first grafted on the surface of the electric materials by sonoelectrochemical method. When the modified materials were dipped into supersaturated calcium phosphate solution for a period of time, the calcium phosphate crystal would grow on the surface. By this technology, bioactive OCP coating has been successfully prepared on carbon/carbon composites, and biomimetic activation was realized on bioinert carbon/carbon composites.
2004, 33(3):317-320.
Abstract:
发展了一种新的VO2薄膜制备方法—V2O5熔化成膜法，其基本步骤为：基片预处理—涂粉—熔化成膜—真空退火—VO2薄膜。采用XRD和XPS等手段，对所得薄膜的物相组成与价态进行了分析，同时对薄膜进行了电阻随温度变化的测试。结果表明：通过该方法获得的薄膜，其主要成分是VO2，电阻突变达到4个数量级，相变温度为67．5℃。
发展了一种新的VO2薄膜制备方法—V2O5熔化成膜法，其基本步骤为：基片预处理—涂粉—熔化成膜—真空退火—VO2薄膜。采用XRD和XPS等手段，对所得薄膜的物相组成与价态进行了分析，同时对薄膜进行了电阻随温度变化的测试。结果表明：通过该方法获得的薄膜，其主要成分是VO2，电阻突变达到4个数量级，相变温度为67．5℃。
2004, 33(3):321-323.
Abstract:
Metallization is necessary for some packaging substrates. It is the key of metallization to improve the adhesion strength between copper plate and ceramic substrates. The adhesion between copper plate and ceramic substrates generally should be more than 15 MPa. Electroplated copper on alumina and aluminum nitride substrates has been studied. It is found that the roughening surface of the substrates can improve the adhesion. The technology of depositing copper plate and the testing methods of adhesion are also studied.
Metallization is necessary for some packaging substrates. It is the key of metallization to improve the adhesion strength between copper plate and ceramic substrates. The adhesion between copper plate and ceramic substrates generally should be more than 15 MPa. Electroplated copper on alumina and aluminum nitride substrates has been studied. It is found that the roughening surface of the substrates can improve the adhesion. The technology of depositing copper plate and the testing methods of adhesion are also studied.
2004, 33(3):324-328.
Abstract:
Scandium oxide bodies doped tungsten have been made by both mechanical mixing scandium oxide with tungsten powder and scandate aqueous solution doping tungsten oxide. The distribution of scandium in the bodies and the anti-ion bombarding property of the Sc-type cathode have been studied by SEM and In Situ AES. For bodies made by aqueous solution- solid doping method, Sc2O3 distributed uniformly in the body. This structure is beneficial for diffusion and supplement of scandate to the suface. In Situ AES ion bombarding experimental results show that this kind of body has better anti-ionbombing property at high temperature.
Scandium oxide bodies doped tungsten have been made by both mechanical mixing scandium oxide with tungsten powder and scandate aqueous solution doping tungsten oxide. The distribution of scandium in the bodies and the anti-ion bombarding property of the Sc-type cathode have been studied by SEM and In Situ AES. For bodies made by aqueous solution- solid doping method, Sc2O3 distributed uniformly in the body. This structure is beneficial for diffusion and supplement of scandate to the suface. In Situ AES ion bombarding experimental results show that this kind of body has better anti-ionbombing property at high temperature.
2004, 33(3):329-332.
Abstract:
采用机械合金化．放电等离子烧结工艺(MA-SPS)，在200℃～600℃之间制备了纳米晶CoSb3合金块体材料。采用XRD和TEM对材料的相组成和微观组织进行了测试分析。实验结果表明，烧结前粉末为高能球磨得到的平均晶粒尺寸为20nm～35nm的纳米晶CoSb3粉末，SPS烧结后CoSb3合金块体的平均晶粒尺寸小于100nm，其致密度达到了91．3％～99．6％。CoSb3块体的晶粒尺寸随着烧结温度的降低而减小，而密度却随着烧结温度的升高而增加。CoSb3纳米晶块体热电材料的制备机理是MA使粉末晶粒细化到纳米级，放电等离子烧结的快速、短时、低温和特殊烧结机理显著抑制了烧结时的晶粒长大。
采用机械合金化．放电等离子烧结工艺(MA-SPS)，在200℃～600℃之间制备了纳米晶CoSb3合金块体材料。采用XRD和TEM对材料的相组成和微观组织进行了测试分析。实验结果表明，烧结前粉末为高能球磨得到的平均晶粒尺寸为20nm～35nm的纳米晶CoSb3粉末，SPS烧结后CoSb3合金块体的平均晶粒尺寸小于100nm，其致密度达到了91．3％～99．6％。CoSb3块体的晶粒尺寸随着烧结温度的降低而减小，而密度却随着烧结温度的升高而增加。CoSb3纳米晶块体热电材料的制备机理是MA使粉末晶粒细化到纳米级，放电等离子烧结的快速、短时、低温和特殊烧结机理显著抑制了烧结时的晶粒长大。
2004, 33(3):333-336.
Abstract:
以Sm和Sm2S3为靶材，采用双靶子溅射系统，于单晶Si基板上成功制作了S-SmS和M-SmS微晶薄膜，并采用XRD，AFM和RBS及光学性能测定等测试手段对薄膜进行了分析测试。结果表明：基板温度低于200℃的情况下；或者在基板温度为400℃，薄膜组成中Sm过量的条件下均可以直接获得在常温常压下稳定存在的M-SmS微晶薄膜。S-SmS和M-SmS微晶薄膜表现出明显不同的光学特性。
以Sm和Sm2S3为靶材，采用双靶子溅射系统，于单晶Si基板上成功制作了S-SmS和M-SmS微晶薄膜，并采用XRD，AFM和RBS及光学性能测定等测试手段对薄膜进行了分析测试。结果表明：基板温度低于200℃的情况下；或者在基板温度为400℃，薄膜组成中Sm过量的条件下均可以直接获得在常温常压下稳定存在的M-SmS微晶薄膜。S-SmS和M-SmS微晶薄膜表现出明显不同的光学特性。
