Volume 0,Issue 5,2000 Table of Contents
2000(5):289-292.
Abstract:
Recent new progress in magnetic functional materials and applications in 1998~1999 is reviewed. The review includes:(1) magnetic sensor new materials;(2) hexagonal system microwave ferrite materials;(3) large capacity spin valve magnetic memories;(4) magnetic thin tape and film transforms;(5) large power application of ferrite materials.
Recent new progress in magnetic functional materials and applications in 1998~1999 is reviewed. The review includes:(1) magnetic sensor new materials;(2) hexagonal system microwave ferrite materials;(3) large capacity spin valve magnetic memories;(4) magnetic thin tape and film transforms;(5) large power application of ferrite materials.
2000(5):293-297.
Abstract:
Progresses and directions of HTS applications world wide are reviewed in this paper, especially with respects to:transmission cables, transformers, fault current limiters(FCL), current leads, motors, flywheel power storage systems, magnetic resonance imagine (MRI), and magnetic levitation trains (Maglev). Prepared and developed in our country are materials for power cables, current leads, FCL, MRI, and Maglev. Accordingly, we should seize the opportunities and face the challenges to optimize the processing of superconducting tapes and bulk materials, to increase their homogeneity, mechanical properties and quantities, to decrease their costs and ac losses, in order to meet the coming new age of HTS commercialization.
Progresses and directions of HTS applications world wide are reviewed in this paper, especially with respects to:transmission cables, transformers, fault current limiters(FCL), current leads, motors, flywheel power storage systems, magnetic resonance imagine (MRI), and magnetic levitation trains (Maglev). Prepared and developed in our country are materials for power cables, current leads, FCL, MRI, and Maglev. Accordingly, we should seize the opportunities and face the challenges to optimize the processing of superconducting tapes and bulk materials, to increase their homogeneity, mechanical properties and quantities, to decrease their costs and ac losses, in order to meet the coming new age of HTS commercialization.
Liu Chunfang
,
Wu Xuan
,
Wang Feiyun
,
Pang Ying
,
Feng Yong
,
Zhang Pingxiang
,
Wu Xiaozu
,
Zhou Lian
2000(5):298-300.
Abstract:
Based on X ray pole figure measurement, the principle, formulas, and practical experimentation on calculating the volume fraction of cubic textured Ni in the substrate for YBCO coated superconductor are presented. The method is reasonable and reliable, and can be used for other components of the texture.
Based on X ray pole figure measurement, the principle, formulas, and practical experimentation on calculating the volume fraction of cubic textured Ni in the substrate for YBCO coated superconductor are presented. The method is reasonable and reliable, and can be used for other components of the texture.
2000(5):304-306.
Abstract:
利用弹性理论分析了稀土原子铈（Ｃｅ）与２０９０铝锂合金中其它溶质原子（Ｃｕ和Ｌｉ）间的交互作用，并采用离子探针和透射电镜（ＴＥＭ）分析研究了微量Ｃｅ的添加对Ｃｕ和Ｌｉ结合能的影响以及富Ｃｕ相（Ｔ１相）形态的变化。研究结果表明：Ｃｕ原子在Ｃｅ原子周围的偏聚比Ｌｉ在Ｃｅ原子周围的偏聚具有更低的弹性势能；微量Ｃｅ的添加对Ｃｕ的结合能产生较大影响，使Ｔ１相表现出较小的长厚比。
利用弹性理论分析了稀土原子铈（Ｃｅ）与２０９０铝锂合金中其它溶质原子（Ｃｕ和Ｌｉ）间的交互作用，并采用离子探针和透射电镜（ＴＥＭ）分析研究了微量Ｃｅ的添加对Ｃｕ和Ｌｉ结合能的影响以及富Ｃｕ相（Ｔ１相）形态的变化。研究结果表明：Ｃｕ原子在Ｃｅ原子周围的偏聚比Ｌｉ在Ｃｅ原子周围的偏聚具有更低的弹性势能；微量Ｃｅ的添加对Ｃｕ的结合能产生较大影响，使Ｔ１相表现出较小的长厚比。
2000(5):307-310.
Abstract:
采用定向凝固连续铸造技术成功制备了纤维增强的自生复合Ｃｕ－Ｃｒ合金电车线线坯，并对自生复合Ｃｕ－Ｃｒ合金的定向凝固特性，包括组织形态、枝晶间距及纤维长度等，作了详细的研究。实验结果表明：保持平面状或胞状的凝固界面有利于纤维状的自生复合组织的形成；当ＧＬ＝２１０℃／ｃｍ，Ｖ＝０．６ｍｍ／ｍｉｎ时，Ｃｕ－０．８％Ｃｒ合金凝固界面呈平面状；增加凝固速率，Ｃｕ－Ｃｒ合金的一次枝晶间距呈先增大后减小的规律，
采用定向凝固连续铸造技术成功制备了纤维增强的自生复合Ｃｕ－Ｃｒ合金电车线线坯，并对自生复合Ｃｕ－Ｃｒ合金的定向凝固特性，包括组织形态、枝晶间距及纤维长度等，作了详细的研究。实验结果表明：保持平面状或胞状的凝固界面有利于纤维状的自生复合组织的形成；当ＧＬ＝２１０℃／ｃｍ，Ｖ＝０．６ｍｍ／ｍｉｎ时，Ｃｕ－０．８％Ｃｒ合金凝固界面呈平面状；增加凝固速率，Ｃｕ－Ｃｒ合金的一次枝晶间距呈先增大后减小的规律，
2000(5):311-314.
Abstract:
The failure stress of two kinds of alumina with six different notch radii were tested. Statistical analysis of the fracture strength indicates that although the fracture strength of smooth specimens conforms to a Weibull distribution, the fracture strength of notched specimen conforms to a normal distribution. The test results show that fracture toughness of structural ceramics also conforms to normal distribution.Therefore the normal distribution will be adopted as reliability design is applied to structural ceramics.
The failure stress of two kinds of alumina with six different notch radii were tested. Statistical analysis of the fracture strength indicates that although the fracture strength of smooth specimens conforms to a Weibull distribution, the fracture strength of notched specimen conforms to a normal distribution. The test results show that fracture toughness of structural ceramics also conforms to normal distribution.Therefore the normal distribution will be adopted as reliability design is applied to structural ceramics.
2000(5):315-320.
Abstract:
Microstructural variation and crack propagation of modified Ti Cr Si silicide coatings on the niobium alloy C 103 during oxidation at high temperatures in air have been studied. The results show that the crack propagation behavior is commonly determined by superficial glass phase, the silicon content of the body coating, and the growth and mechanical properties of low valent silicide.
Microstructural variation and crack propagation of modified Ti Cr Si silicide coatings on the niobium alloy C 103 during oxidation at high temperatures in air have been studied. The results show that the crack propagation behavior is commonly determined by superficial glass phase, the silicon content of the body coating, and the growth and mechanical properties of low valent silicide.
2000(5):324-327.
Abstract:
采用俄歇电子能谱法研究了 Mo- L a2 O3阴极材料中 L a2 O3向表面的富集过程。结果表明 ,在高温下 ,L a2 O3以 L a3+ ,O2 - 离子的形式分别向表面扩散 ,然后在表面上重新结合成分子。在 112 3 K～ 142 3 K范围内 ,L a3+ ,O2 -离子的扩散系数分别为 :DL a=3.6 70 3× 10 - 1 6 exp (- 1.0 16 39× 10 5 / RT) m2 / s;DO=1.5 12 2× 10 - 1 6 exp (- 8.130 6 6× 10 4/ RT) m2 / s
采用俄歇电子能谱法研究了 Mo- L a2 O3阴极材料中 L a2 O3向表面的富集过程。结果表明 ,在高温下 ,L a2 O3以 L a3+ ,O2 - 离子的形式分别向表面扩散 ,然后在表面上重新结合成分子。在 112 3 K～ 142 3 K范围内 ,L a3+ ,O2 -离子的扩散系数分别为 :DL a=3.6 70 3× 10 - 1 6 exp (- 1.0 16 39× 10 5 / RT) m2 / s;DO=1.5 12 2× 10 - 1 6 exp (- 8.130 6 6× 10 4/ RT) m2 / s
2000(5):332-335.
Abstract:
The main defects frequently occurring in injection molded cemented carbide parts and their origin have been analyzed. Some effective measures to reduce or avoid the defects are proposed. The application prospects and some problems that need to be solved in the powder injection molding of cemented carbides are discussed in detail.
The main defects frequently occurring in injection molded cemented carbide parts and their origin have been analyzed. Some effective measures to reduce or avoid the defects are proposed. The application prospects and some problems that need to be solved in the powder injection molding of cemented carbides are discussed in detail.
2000(5):344-346.
Abstract:
The burning behavior of titanium alloys in a mixture of Ar and O 2, and a way of extinguishing the titanium fire have been studied. It was shown that titanium burns in an oxygen rich atmosphere, and that Ar gas can be used to extinguish the fire. Both the burning products and interface between the burning products and matrix are porous when titanium burns in an oxygen rich atmosphere.
The burning behavior of titanium alloys in a mixture of Ar and O 2, and a way of extinguishing the titanium fire have been studied. It was shown that titanium burns in an oxygen rich atmosphere, and that Ar gas can be used to extinguish the fire. Both the burning products and interface between the burning products and matrix are porous when titanium burns in an oxygen rich atmosphere.
2000(5):347-349.
Abstract:
The effects of macromolecular dispersant and subzero treatment on the preparation of ultrafine non agglomerative zirconia powders have been studied. The results show that adding a macromolecular dispersant at the beginning of deposition, and the subzero treatment after the wet gel being neutrality not only shorten the cleaning period, but also avoid the agglomeration of zirconia powders(particle size of 10 nm~30 nm). The mechanism is also discussed and analyzed.
The effects of macromolecular dispersant and subzero treatment on the preparation of ultrafine non agglomerative zirconia powders have been studied. The results show that adding a macromolecular dispersant at the beginning of deposition, and the subzero treatment after the wet gel being neutrality not only shorten the cleaning period, but also avoid the agglomeration of zirconia powders(particle size of 10 nm~30 nm). The mechanism is also discussed and analyzed.
2000(5):350-353.
Abstract:
In order to improve the resistance to natural aging and softening, and property stability of ornamental silver, the dependences of mechanical properties of the silver alloyed with 0 12 wt%(La+Y) on aging temperature have been studied. The experimental results show that the hardness and resistance to softening of Ag can be improved by the addition of small amounts of rare earth elements. SEM analysis indicate that significant grain refinement result. The rare earth additions effectively defer the recovery and recrystallization of silver, thereby improving the resistance to natural aging and softening, and increasing the repeatablility of property.
In order to improve the resistance to natural aging and softening, and property stability of ornamental silver, the dependences of mechanical properties of the silver alloyed with 0 12 wt%(La+Y) on aging temperature have been studied. The experimental results show that the hardness and resistance to softening of Ag can be improved by the addition of small amounts of rare earth elements. SEM analysis indicate that significant grain refinement result. The rare earth additions effectively defer the recovery and recrystallization of silver, thereby improving the resistance to natural aging and softening, and increasing the repeatablility of property.
2000(5):354-356.
Abstract:
TiO 2 nano powders were prepared by means of microwave radiation using the collosol of titanium dioxide hydrate made from sponge titanium. TEM analysis indicates that the morphology of the nano particles is spherical, and the particle size is in the range of 60 nm~100 nm. The distribution of the particle size is fine. The Zeta potential value of the sample in water is +48 7 mV, indicaling good dispersivity. The transformation temperature of the nano crystal is much lower than that of the common crystal. The starting material is cheaper, and using this method nano particle size is easily controlled in production.
TiO 2 nano powders were prepared by means of microwave radiation using the collosol of titanium dioxide hydrate made from sponge titanium. TEM analysis indicates that the morphology of the nano particles is spherical, and the particle size is in the range of 60 nm~100 nm. The distribution of the particle size is fine. The Zeta potential value of the sample in water is +48 7 mV, indicaling good dispersivity. The transformation temperature of the nano crystal is much lower than that of the common crystal. The starting material is cheaper, and using this method nano particle size is easily controlled in production.
2000(5):357-359.
Abstract:
试验证实了高温下铂铑 10 -铂热电偶在 H2 或 CO气氛中使用时因脆性而会很快断裂失效。采用透射电镜(TEM)对脆断偶丝进行了研究认为 :脆断失效的根本原因在于 Si与 Pt作用形成 Pt5 Si2 低熔点共晶物 ,使偶丝局部熔点降低而熔化 ,发生脆断。通过采用 Sol Gel Dip Coating工艺在铂铑 10 -铂热电偶丝上成功制备了 Al2 O3· Y2 O3涂层。对涂层铂铑 10 -铂热电偶分别在 H2 和 CO还原性气氛中进行了试验研究 ,结果表明涂层铂铑 10 -铂热电偶试样可通过还原性气氛中长期稳定性试验 ,克服了脆断失效问题
试验证实了高温下铂铑 10 -铂热电偶在 H2 或 CO气氛中使用时因脆性而会很快断裂失效。采用透射电镜(TEM)对脆断偶丝进行了研究认为 :脆断失效的根本原因在于 Si与 Pt作用形成 Pt5 Si2 低熔点共晶物 ,使偶丝局部熔点降低而熔化 ,发生脆断。通过采用 Sol Gel Dip Coating工艺在铂铑 10 -铂热电偶丝上成功制备了 Al2 O3· Y2 O3涂层。对涂层铂铑 10 -铂热电偶分别在 H2 和 CO还原性气氛中进行了试验研究 ,结果表明涂层铂铑 10 -铂热电偶试样可通过还原性气氛中长期稳定性试验 ,克服了脆断失效问题
