Volume 0,Issue 4,2001 Table of Contents
2001(4).
Abstract:
In order to get an insight of the relations between the compositions, the microstructures and the mechanical properties, the experimental high-temperature structural intermetallic alloys comprised of L2_1-type(Co,Ni)_2AlTi and L1_2-type(Co,Ni)_3(Al,Ti) ordered phases in the system Co-Ni-Al-Ti were examined for various heat-treated microstructures by compression testing and fracture analysis. Some approaches to further improving the high-temperature strength and room-temperature ductility are discussed.
In order to get an insight of the relations between the compositions, the microstructures and the mechanical properties, the experimental high-temperature structural intermetallic alloys comprised of L2_1-type(Co,Ni)_2AlTi and L1_2-type(Co,Ni)_3(Al,Ti) ordered phases in the system Co-Ni-Al-Ti were examined for various heat-treated microstructures by compression testing and fracture analysis. Some approaches to further improving the high-temperature strength and room-temperature ductility are discussed.
2001(4).
Abstract:
The Al_2O_3 ceramics was bonded with Ti-6Al-4V using (Ag_ 72Cu_ 28)_ 97Ti_3 as filler metal under the conditions of 1 073 k~1 173 K and 18 ks. The interface structure and formation mechanism of joints were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). It was found that the interface structure of diffusion-bonded joints is Al_2O_3/Cu_2Ti_4O/Cu_4Ti_3/Ag-Cu eutectic+rich Ag phase+Ti soild solution for bonding temperature below 1 123 K. For bonding temperature of 1 173 K, the interface structure is Al_2O_3/Cu_3TiO_5+CuAl_2O_4/Cu_4Ti_3/rich Ag phase. Strength of the Al_2O_3/(Ag_ 72Cu_ 28)_ 97Ti_3/Nb joint reaches 189 MPa for bonding temperature of 1 123 K and 18 ks. The lower bonding temperature, or the higher bonding temperature, the lower strength of joints.
The Al_2O_3 ceramics was bonded with Ti-6Al-4V using (Ag_ 72Cu_ 28)_ 97Ti_3 as filler metal under the conditions of 1 073 k~1 173 K and 18 ks. The interface structure and formation mechanism of joints were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). It was found that the interface structure of diffusion-bonded joints is Al_2O_3/Cu_2Ti_4O/Cu_4Ti_3/Ag-Cu eutectic+rich Ag phase+Ti soild solution for bonding temperature below 1 123 K. For bonding temperature of 1 173 K, the interface structure is Al_2O_3/Cu_3TiO_5+CuAl_2O_4/Cu_4Ti_3/rich Ag phase. Strength of the Al_2O_3/(Ag_ 72Cu_ 28)_ 97Ti_3/Nb joint reaches 189 MPa for bonding temperature of 1 123 K and 18 ks. The lower bonding temperature, or the higher bonding temperature, the lower strength of joints.
3 Study on the Electrochemical Performances of Intermetallic Compound CoSb_3 in Lithium-Ions Batteries
2001(4).
Abstract:
研究了金属间化合物 Co Sb3作为锂离子电池阳极材料在 1ML i PF6 /EC+ DMC( 1∶ 1)电解液中的电化学性能。具有 skutterudite结构的 Co Sb3和不具有此种结构的 Co Sb3最大可逆容量分别为 5 73 m Ah· g- 1 和 4 4 4 m Ah·g- 1 ,10个循环内可逆容量分别保持在 4 0 0 m Ah· g- 1和 2 2 0 m Ah·g- 1以上 ,采用非原位 XRD方法研究二者嵌锂机理 ,发现 skutterudite结构虽然不起储锂作用 ,但它破坏后形成的微观结构却有利于循环过程。加入 10 % (质量分数 ,下同 )微碳球 MCMB后 Co Sb3电化学性能大大提高 ,最大可逆容量达 715 m Ah· g- 1 ,循环 2 0次后可逆容量保持在 5 0 0 m Ah· g- 1 以上。
研究了金属间化合物 Co Sb3作为锂离子电池阳极材料在 1ML i PF6 /EC+ DMC( 1∶ 1)电解液中的电化学性能。具有 skutterudite结构的 Co Sb3和不具有此种结构的 Co Sb3最大可逆容量分别为 5 73 m Ah· g- 1 和 4 4 4 m Ah·g- 1 ,10个循环内可逆容量分别保持在 4 0 0 m Ah· g- 1和 2 2 0 m Ah·g- 1以上 ,采用非原位 XRD方法研究二者嵌锂机理 ,发现 skutterudite结构虽然不起储锂作用 ,但它破坏后形成的微观结构却有利于循环过程。加入 10 % (质量分数 ,下同 )微碳球 MCMB后 Co Sb3电化学性能大大提高 ,最大可逆容量达 715 m Ah· g- 1 ,循环 2 0次后可逆容量保持在 5 0 0 m Ah· g- 1 以上。
2001(4).
Abstract:
The rare earth oxide La_ 065Ca_ x MnO_3 with Ca vacancies were prepared, and the magnetic and electric transport behaviors were investigated. The experimental results show that with increasing Ca vacancies, the unit cell volume of La_ 065Ca _x MnO_3 increases, but the Curit temperature decreases and the ferromagnetic interaction is suppressed. The temperature of metal semiconductor transition, T _ tran, decreases, and the peak value of resistance increases with increasing Ca vacancies. The temperature dependence of the resistance above metal-semiconductor transition temperature is simulated based on the polaron-resistance model. The simulated results indicate that the increment of resistance for materials with Ca vacancies is associated with the decrement of decay length of local wave function. Meanwhile, the temperature dependence of resistance from 100 K to 300 K is calculated based on the Dionne model. The calculated data show that the polaron-trapping energy resulted from both the magnetic exchange interaction and the electron-phonon interaction enhance with increasing Ca vacancies, which reduces the active ability of the current carrier. The relationships among Ca content, amount of ions Mn 3+/Mn 4+ and oxygen vacancies in La_ 065Ca _x MnO_3 are also discussed in details.
The rare earth oxide La_ 065Ca_ x MnO_3 with Ca vacancies were prepared, and the magnetic and electric transport behaviors were investigated. The experimental results show that with increasing Ca vacancies, the unit cell volume of La_ 065Ca _x MnO_3 increases, but the Curit temperature decreases and the ferromagnetic interaction is suppressed. The temperature of metal semiconductor transition, T _ tran, decreases, and the peak value of resistance increases with increasing Ca vacancies. The temperature dependence of the resistance above metal-semiconductor transition temperature is simulated based on the polaron-resistance model. The simulated results indicate that the increment of resistance for materials with Ca vacancies is associated with the decrement of decay length of local wave function. Meanwhile, the temperature dependence of resistance from 100 K to 300 K is calculated based on the Dionne model. The calculated data show that the polaron-trapping energy resulted from both the magnetic exchange interaction and the electron-phonon interaction enhance with increasing Ca vacancies, which reduces the active ability of the current carrier. The relationships among Ca content, amount of ions Mn 3+/Mn 4+ and oxygen vacancies in La_ 065Ca _x MnO_3 are also discussed in details.
2001(4).
Abstract:
采用球磨湿混和旋转合成相结合的新工艺制备了锂离子电池正极材料 L i Ni0 .5Co0 .5O2 ,并对材料进行了粒度、化学成分以及电化学性能测试。球磨湿混工艺能将原料混合均匀 ,并能有效地使粒度细化。旋转合成工艺能使混合料在均匀的温度场中进行反应 ,并使反应产物粒度均匀和成分均匀。制备的 L i Ni0 .5Co0 .5O2 为单一的 α- Na Fe O2 层状结构 ,粉末粒度分布范围窄 ,平均粒径约为 8μm～ 10μm。电化学性能测试结果表明 ,在 0 .2 m A/cm2 充放电流密度和 3 .0 V～ 4 .2 V电压范围内 ,首次充电容量为 173 m Ah/g,放电容量为 14 8m Ah/g。循环次数达 3 0次时 ,放电容量还有 12 9m Ah/g,循环稳定性良好。球磨湿混和旋转合成相结合的固相合成新工艺能制备出电化学性能良好的L i Ni0 .5Co0 .5O2 正极材料。
采用球磨湿混和旋转合成相结合的新工艺制备了锂离子电池正极材料 L i Ni0 .5Co0 .5O2 ,并对材料进行了粒度、化学成分以及电化学性能测试。球磨湿混工艺能将原料混合均匀 ,并能有效地使粒度细化。旋转合成工艺能使混合料在均匀的温度场中进行反应 ,并使反应产物粒度均匀和成分均匀。制备的 L i Ni0 .5Co0 .5O2 为单一的 α- Na Fe O2 层状结构 ,粉末粒度分布范围窄 ,平均粒径约为 8μm～ 10μm。电化学性能测试结果表明 ,在 0 .2 m A/cm2 充放电流密度和 3 .0 V～ 4 .2 V电压范围内 ,首次充电容量为 173 m Ah/g,放电容量为 14 8m Ah/g。循环次数达 3 0次时 ,放电容量还有 12 9m Ah/g,循环稳定性良好。球磨湿混和旋转合成相结合的固相合成新工艺能制备出电化学性能良好的L i Ni0 .5Co0 .5O2 正极材料。
2001(4).
Abstract:
研究了贮氢合金 Ml Ni3.6 5Co0 .75Mn0 .4 Al0 .2 的颗粒度及粒度分布均匀性对其电化学性能的影响。结果表明 :在2 0 0 m A/g(以贮氢合金的质量计算 ,下同 )的充放电电流下 ,合金的粒度越小 ,首次放电容量越大 ,且活化速度越快 ,但其饱和容量 (活化后稳定的放电容量 )随粒度的增大而增加 ,且在某个最佳粒度时达到最大值 ,然后又逐渐降低 ;该合金的高倍率放电容量与其粒度之间也有相同的规律 ,只是在不同的放电电流下最佳粒度值不同 ,当放电电流小于 60 0 m A/g时 ,3 0μm～ 76μm合金粉的放电容量最大 ,当放电电流等于或大于 60 0 m A/g时 ,4 0μm～ 5 0μm合金粉的放电容量最大 ;放电电流越大 ,颗粒度对合金粉电化学性能的影响越显著 ;在充放电电流为 3 0 0 m A/g时 ,除3 0μm以下的合金粉性能衰减较快外 ,其余各个粒度的合金粉的性能衰减速度几乎相等 ;均匀的粒度分布有利于合金粉电化学性能的提高。
研究了贮氢合金 Ml Ni3.6 5Co0 .75Mn0 .4 Al0 .2 的颗粒度及粒度分布均匀性对其电化学性能的影响。结果表明 :在2 0 0 m A/g(以贮氢合金的质量计算 ,下同 )的充放电电流下 ,合金的粒度越小 ,首次放电容量越大 ,且活化速度越快 ,但其饱和容量 (活化后稳定的放电容量 )随粒度的增大而增加 ,且在某个最佳粒度时达到最大值 ,然后又逐渐降低 ;该合金的高倍率放电容量与其粒度之间也有相同的规律 ,只是在不同的放电电流下最佳粒度值不同 ,当放电电流小于 60 0 m A/g时 ,3 0μm～ 76μm合金粉的放电容量最大 ,当放电电流等于或大于 60 0 m A/g时 ,4 0μm～ 5 0μm合金粉的放电容量最大 ;放电电流越大 ,颗粒度对合金粉电化学性能的影响越显著 ;在充放电电流为 3 0 0 m A/g时 ,除3 0μm以下的合金粉性能衰减较快外 ,其余各个粒度的合金粉的性能衰减速度几乎相等 ;均匀的粒度分布有利于合金粉电化学性能的提高。
2001(4):241-244.
Abstract:
The reaction rate of in situ formed TiC in molten aluminum has been studied. The calculated results show that decreasing the aluminum content in Ti-C-Al preform accelerates the reaction rate of TiC. Increasing the thickness of intermetallide layer and the size of C power reduces the reaction rate of TiC.
The reaction rate of in situ formed TiC in molten aluminum has been studied. The calculated results show that decreasing the aluminum content in Ti-C-Al preform accelerates the reaction rate of TiC. Increasing the thickness of intermetallide layer and the size of C power reduces the reaction rate of TiC.
2001(4):245-248.
Abstract:
The un-uniformed deformation TiC particle reinforced titanium matrix composite has been studied. The results show that the deformed frictional constraint appears between the particle and the matrix and resists the deformation of matrix and strengthens it.By using the theory of elastic-plastic mechanics,the deformed frictional constraint calculated is 0.6 times of the strength of TiC particle,when the stress gathering appears on the interface and the dislocation resource are formed at a certain crystalline plane,a series of dislocation rings release and the stress gathering on the interface is freed,in the meantime the density of dislocation in the matrix increases,the dislocations tangle each other to form celluloid substructure and thus strengthen the matrix.
The un-uniformed deformation TiC particle reinforced titanium matrix composite has been studied. The results show that the deformed frictional constraint appears between the particle and the matrix and resists the deformation of matrix and strengthens it.By using the theory of elastic-plastic mechanics,the deformed frictional constraint calculated is 0.6 times of the strength of TiC particle,when the stress gathering appears on the interface and the dislocation resource are formed at a certain crystalline plane,a series of dislocation rings release and the stress gathering on the interface is freed,in the meantime the density of dislocation in the matrix increases,the dislocations tangle each other to form celluloid substructure and thus strengthen the matrix.
2001(4):249-252.
Abstract:
对于由L21型（Co,Ni)2AlTi和L1型（Co,Ni)3(Al,Ti)两种有序相组成的Co-Ni-Al-Ti系新型金属间化合物高温结构用合金，经热处理后获得不同显微组织的高温压缩和室温断裂等力学行为进行了分析研究，确立了合金成分、显微组织和机械性能之间的关系，找到了进一步提高高温强度和室温塑性的途径。
对于由L21型（Co,Ni)2AlTi和L1型（Co,Ni)3(Al,Ti)两种有序相组成的Co-Ni-Al-Ti系新型金属间化合物高温结构用合金，经热处理后获得不同显微组织的高温压缩和室温断裂等力学行为进行了分析研究，确立了合金成分、显微组织和机械性能之间的关系，找到了进一步提高高温强度和室温塑性的途径。
2001(4):253-256.
Abstract:
The purification by plasma during sedimentation of particulates is studied in this paper. The analyzed and calculated data show that when sedimentation rate and time are suitable, the purity of particulates can be improved by two orders of magnitude. Some calculated data and improvements on purification are discussed in detail.
The purification by plasma during sedimentation of particulates is studied in this paper. The analyzed and calculated data show that when sedimentation rate and time are suitable, the purity of particulates can be improved by two orders of magnitude. Some calculated data and improvements on purification are discussed in detail.
2001(4):257-260.
Abstract:
In order to understand the behaviors of dissolution of TiN inclusions in liquid titanium alloys and evaluate the roles of alloying elements in the diffusion process, the diffusion and phase transformation near alpha region of TiN\Ti interface in C_pTi and Ti-6Al-4V have been studied. The artificially embedded TiN sponge particles dissolved into liquid alloys. The concentration profiles of nitrogen in the interfaces have been determined by microprobe for either as-cast or heat-treated samples. The experimental results show that the concentration profiles of nitrogen in phase transformation region show a steep change. The alloying elements Al and V retard the diffusion of nitrogen and dissolution of TiN particles.
In order to understand the behaviors of dissolution of TiN inclusions in liquid titanium alloys and evaluate the roles of alloying elements in the diffusion process, the diffusion and phase transformation near alpha region of TiN\Ti interface in C_pTi and Ti-6Al-4V have been studied. The artificially embedded TiN sponge particles dissolved into liquid alloys. The concentration profiles of nitrogen in the interfaces have been determined by microprobe for either as-cast or heat-treated samples. The experimental results show that the concentration profiles of nitrogen in phase transformation region show a steep change. The alloying elements Al and V retard the diffusion of nitrogen and dissolution of TiN particles.
2001(4):261-263.
Abstract:
Thermal cycling conditions are among the most sever environmental conditions for composites and have a great effect on the micromechanical properties near interfaces.An AFM(atomic force microscope)-based nanoindentation method was employed to measure the nanohardness and the plastic deformation capacity near interfaces in graphite fiber reinforced aluminum alloy matrix composites(Gr/Al)after thermal cycling.With increasing of thermal cycles, the nanohardness values of both fibers and the matrix decrease and the plastic deformation capacity of the matrix increases.Both of the changes in the nanohardness and the plastic deformation capacity are dependent of the distance to the fiber-matrix interface.Changes in nanohardness can provide important information about residual strains because the local elastic or plastic residual strains have effects on the local hardness.
Thermal cycling conditions are among the most sever environmental conditions for composites and have a great effect on the micromechanical properties near interfaces.An AFM(atomic force microscope)-based nanoindentation method was employed to measure the nanohardness and the plastic deformation capacity near interfaces in graphite fiber reinforced aluminum alloy matrix composites(Gr/Al)after thermal cycling.With increasing of thermal cycles, the nanohardness values of both fibers and the matrix decrease and the plastic deformation capacity of the matrix increases.Both of the changes in the nanohardness and the plastic deformation capacity are dependent of the distance to the fiber-matrix interface.Changes in nanohardness can provide important information about residual strains because the local elastic or plastic residual strains have effects on the local hardness.
2001(4):264-267.
Abstract:
在1．8ks，1073K－1173K条件下对Al2O3/(Ag72Cu28)97Ti3/Ti-6Al-4V进行了钎焊试验。通过扫描电镜、波谱、能谱、X射线衍射界面结构进行了分析。小于1123K的界面结构为Al2O3/Cu2Ti4O/Cu4Ti3/Ag-Cu共晶＋富Ag相＋Ti固溶体；1173K的界面结构为Al2O3/Cu3TiO5 CuAl2O4/Cu4Ti3/富Ag相。采用拉剪试验测试了接头剪切强度。在1．8ks,1123K时剪切强度最高达到189MPa,大于或小于1123K接头强度呈下降趋势。
在1．8ks，1073K－1173K条件下对Al2O3/(Ag72Cu28)97Ti3/Ti-6Al-4V进行了钎焊试验。通过扫描电镜、波谱、能谱、X射线衍射界面结构进行了分析。小于1123K的界面结构为Al2O3/Cu2Ti4O/Cu4Ti3/Ag-Cu共晶＋富Ag相＋Ti固溶体；1173K的界面结构为Al2O3/Cu3TiO5 CuAl2O4/Cu4Ti3/富Ag相。采用拉剪试验测试了接头剪切强度。在1．8ks,1123K时剪切强度最高达到189MPa,大于或小于1123K接头强度呈下降趋势。
14 Study on The Electrochemical Performances of Intermetallic Compound CoSb3
in Lithium-Ions Batteries
2001(4):268-272.
Abstract:
研究了金属间化合物CoSb3作为锂离子电池阳极材料在1MLiPF6/EC+DMC(1∶1)电解液中的电化学性能.具有skutterudite结构的CoSb3和不具有此种结构的CoSb3最大可逆容量分别为573mAh*g-1和444mAh*g-1,10个循环内可逆容量分别保持在400mAh*g-1和220mAh*g-1以上,采用非原位XRD方法研究二者嵌锂机理,发现skutterudite结构虽然不起储锂作用,但它破坏后形成的微观结构却有利于循环过程.加入10%(质量分数,下同)微碳球MCMB后CoSb3电化学性能大大提高,最大可逆容量达715mAh*g-1,循环20次后可逆容量保持在500mAh*g-1以上.
研究了金属间化合物CoSb3作为锂离子电池阳极材料在1MLiPF6/EC+DMC(1∶1)电解液中的电化学性能.具有skutterudite结构的CoSb3和不具有此种结构的CoSb3最大可逆容量分别为573mAh*g-1和444mAh*g-1,10个循环内可逆容量分别保持在400mAh*g-1和220mAh*g-1以上,采用非原位XRD方法研究二者嵌锂机理,发现skutterudite结构虽然不起储锂作用,但它破坏后形成的微观结构却有利于循环过程.加入10%(质量分数,下同)微碳球MCMB后CoSb3电化学性能大大提高,最大可逆容量达715mAh*g-1,循环20次后可逆容量保持在500mAh*g-1以上.
2001(4):273-276.
Abstract:
利用传热模型和物理模型计算了等离子旋转电极法（简称PREP）和锤砧法（简称HAP）制备的TiAl合金的冷却速度。计算结果显示：以高纯氩为冷却介质，PREP法制备的TiAl合金的冷却速度为10^2K/s-10^4K/s；锤砧法的冷速为10^5K/s-10^6K/s。
利用传热模型和物理模型计算了等离子旋转电极法（简称PREP）和锤砧法（简称HAP）制备的TiAl合金的冷却速度。计算结果显示：以高纯氩为冷却介质，PREP法制备的TiAl合金的冷却速度为10^2K/s-10^4K/s；锤砧法的冷速为10^5K/s-10^6K/s。
2001(4):277-280.
Abstract:
制备了Ca缺位型稀土金属氧化物La0.65CaxMnO3，并对磁性及电输运特性进行了研究。发现随Ca缺位的增加，材料的晶胞体积增大，但居里温度却减小，铁磁相互作用减弱。材料的金属－半导体转换峰值温度Ttran随Ca缺位程度的增加相应减小而电池峰值却增大，作者用极化子电阻模拟合了金属-半导体转换峰温度Ttran以上的电阻温度依赖关系，发现Ca缺位材料的电阻的增大可能与局域波函数的衰减长度减小有关。还同时利用迪尼模型在100K－300K温区内，分析计算了材料电阻随温度的变化关系，发现磁交换能和电－声相互作用能对极化陷阱能的贡献有有Ca缺位时比无缺位时均有所增大。极化陷阱的增高减低了载流子的活动能力。同时还对Ca含量、Mn^ 3/Mn^ 4含量、氧缺位量存在的关系进行了讨论。
制备了Ca缺位型稀土金属氧化物La0.65CaxMnO3，并对磁性及电输运特性进行了研究。发现随Ca缺位的增加，材料的晶胞体积增大，但居里温度却减小，铁磁相互作用减弱。材料的金属－半导体转换峰值温度Ttran随Ca缺位程度的增加相应减小而电池峰值却增大，作者用极化子电阻模拟合了金属-半导体转换峰温度Ttran以上的电阻温度依赖关系，发现Ca缺位材料的电阻的增大可能与局域波函数的衰减长度减小有关。还同时利用迪尼模型在100K－300K温区内，分析计算了材料电阻随温度的变化关系，发现磁交换能和电－声相互作用能对极化陷阱能的贡献有有Ca缺位时比无缺位时均有所增大。极化陷阱的增高减低了载流子的活动能力。同时还对Ca含量、Mn^ 3/Mn^ 4含量、氧缺位量存在的关系进行了讨论。
2001(4):281-285.
Abstract:
用纳米压入法测定了LY12铝合金微弧氧化陶瓷膜的硬度H和弹性模量E分布，并探讨了陶瓷氧化膜的生长机理。氧化膜的硬度和弹性模量分别为18GPa-32GPa,280GPa-390GPa。靠近膜／基体界面的氧化膜硬度和弹性模量仍然相当高。H和E沿膜深度的分布都存在一个极大值，并同膜内α-Al2O3含量变化是一致的。其形成原因在于微弧区熔融物在膜不同部位冷却速率差异较大。
用纳米压入法测定了LY12铝合金微弧氧化陶瓷膜的硬度H和弹性模量E分布，并探讨了陶瓷氧化膜的生长机理。氧化膜的硬度和弹性模量分别为18GPa-32GPa,280GPa-390GPa。靠近膜／基体界面的氧化膜硬度和弹性模量仍然相当高。H和E沿膜深度的分布都存在一个极大值，并同膜内α-Al2O3含量变化是一致的。其形成原因在于微弧区熔融物在膜不同部位冷却速率差异较大。
2001(4):286-289.
Abstract:
The effects of additive Ni and Co on the microstructures and characteristics of CuCr25 alloys prepared by vacuum induction melting have been studied. The results show that both Ni and Co eliminate Cr segregation, and significantly improve the microstructures of CuCr25 alloys. The additive Ni and Co also increase the dielectric strength of the alloys, but slightly decrease electrical conductivity. As a result, the properties of vacuum induction melted CuCr25 alloys reach the specifications of conventional CuCr50 alloy.
The effects of additive Ni and Co on the microstructures and characteristics of CuCr25 alloys prepared by vacuum induction melting have been studied. The results show that both Ni and Co eliminate Cr segregation, and significantly improve the microstructures of CuCr25 alloys. The additive Ni and Co also increase the dielectric strength of the alloys, but slightly decrease electrical conductivity. As a result, the properties of vacuum induction melted CuCr25 alloys reach the specifications of conventional CuCr50 alloy.
2001(4):290-294.
Abstract:
The CuCr25 alloys with high density and low oxygen content were prepared by means of vacuum induction melting. The effects of alloying elements (Ni-Al,W-Ni,W-Co) and microstructure on the physical properties and dielectric strength were investigated.The experimental results show that the chromium grains are refined when appropriate solidifying method and alloying elements are selected.On the other hand, the tungsten and cobalt serve the function of strengthening chromium phase.As a result, the dielectric strength increases notably.
The CuCr25 alloys with high density and low oxygen content were prepared by means of vacuum induction melting. The effects of alloying elements (Ni-Al,W-Ni,W-Co) and microstructure on the physical properties and dielectric strength were investigated.The experimental results show that the chromium grains are refined when appropriate solidifying method and alloying elements are selected.On the other hand, the tungsten and cobalt serve the function of strengthening chromium phase.As a result, the dielectric strength increases notably.
2001(4):295-298.
Abstract:
The alloy Cu-Ag with high strength and conductivity is studied in this paper. The tensile strength of 11 GPa and the conductivity of 80% international annealing copper standard (IACS) for the alloy have been obtained. The influences of deformation, heat treatment and alloying constituent on comprehensive properties of the alloy are discussed, and the strengthening mechanism is also analyzed.
The alloy Cu-Ag with high strength and conductivity is studied in this paper. The tensile strength of 11 GPa and the conductivity of 80% international annealing copper standard (IACS) for the alloy have been obtained. The influences of deformation, heat treatment and alloying constituent on comprehensive properties of the alloy are discussed, and the strengthening mechanism is also analyzed.
21 Synthesis and Electrochemical Properties of LiNi0.5Co0.5O2
Cathode Material for Lithium Ion Battery
2001(4):299-302.
Abstract:
采用球磨湿混和旋转合成相结合的新工艺制备了锂离子电池正极材料LiNi0.5Co0.5O2，并对材料进行了粒度、化学成分以及电化学性能测试。球磨湿混工艺能将原料混合均匀，并能有效地使粒度细化。旋转合成工艺能使混合料在均匀的温度场中进行反应，并使反应产物粒度均匀和成分均匀。制备的LiNi0.5Co0.5O2为单一的α-NaFeO2层状结构，粉末粒度分布范围窄，平均粒径约为8μm-10μm。电化学性能测试结果表明，在0．2mA/cm^2充放电流密度和3．0V－4．2V电压范围内，首次充电容量为173mAh/g，放电容量为148mAh/g。循环次数达30次时， 放电容量还有129mAh/g，循环稳定性良好。球磨湿混和旋转合成相结合的固相合成新工艺能制备出电化学性能良好的LiNi0.5Co0.5O2正极材料。
采用球磨湿混和旋转合成相结合的新工艺制备了锂离子电池正极材料LiNi0.5Co0.5O2，并对材料进行了粒度、化学成分以及电化学性能测试。球磨湿混工艺能将原料混合均匀，并能有效地使粒度细化。旋转合成工艺能使混合料在均匀的温度场中进行反应，并使反应产物粒度均匀和成分均匀。制备的LiNi0.5Co0.5O2为单一的α-NaFeO2层状结构，粉末粒度分布范围窄，平均粒径约为8μm-10μm。电化学性能测试结果表明，在0．2mA/cm^2充放电流密度和3．0V－4．2V电压范围内，首次充电容量为173mAh/g，放电容量为148mAh/g。循环次数达30次时， 放电容量还有129mAh/g，循环稳定性良好。球磨湿混和旋转合成相结合的固相合成新工艺能制备出电化学性能良好的LiNi0.5Co0.5O2正极材料。
2001(4):303-305.
Abstract:
利用透射电镜观察了Al-4Cr-4Zr-2Ti（原子百分比）合金的显微组织，并测定了相应的显微硬度。结果表明：快凝合金在400℃，4h时效达到峰值硬度，Hv达2420MPa，此时的析出相为Al13Cr2和与基体共格的亚稳相Ll2-Al3Zr。合金经400℃，96h时效后的显微硬度与急冷态硬度和峰值硬度相比仅分别下降10％和14％。而500℃，4h时效后，由于Ll2-Al3Zr转变为DO23－Al3Zr并且析出相粗化，导致合金硬度急剧下降。
利用透射电镜观察了Al-4Cr-4Zr-2Ti（原子百分比）合金的显微组织，并测定了相应的显微硬度。结果表明：快凝合金在400℃，4h时效达到峰值硬度，Hv达2420MPa，此时的析出相为Al13Cr2和与基体共格的亚稳相Ll2-Al3Zr。合金经400℃，96h时效后的显微硬度与急冷态硬度和峰值硬度相比仅分别下降10％和14％。而500℃，4h时效后，由于Ll2-Al3Zr转变为DO23－Al3Zr并且析出相粗化，导致合金硬度急剧下降。
2001(4):306-309.
Abstract:
研究了贮氢合金MlNi3.65Co0.75Mn0.4Al0.2的颗粒浓度及粒度分布均匀性对其电化学性能的影响。结果表明：在200mA/g（以贮氢合金的质量计算，下同）的充放电电流下，合金的粒度越小，首次放电容量越大，且活化速度越快，但其饱和容量（活化后稳定的放电容量）随粒度的增大而增加，且在某个最佳粒度时达到最大值，然后又逐渐降低；该合金的高倍率放电容量与其粒度之间也有相同的规律，只是在不同的放电电流下最佳粒度值不同，当放电电流小于600mA/g时，30μm-76μm合金粉的放电容量最大，当放电电流等于或大于600mA/g时，40μm-50μm合金粉的放电容量最大；放电电流越大，颗粒度对合金粉电化学性能的影响越显著；在放电电流为300mA/g时，除30μm以下的合金粉性能衰减较快外，其余各个粒度的合金粉的性能衰减速度几乎相等；均匀的粒度分布有利于合金粉电化学性能的提高。
研究了贮氢合金MlNi3.65Co0.75Mn0.4Al0.2的颗粒浓度及粒度分布均匀性对其电化学性能的影响。结果表明：在200mA/g（以贮氢合金的质量计算，下同）的充放电电流下，合金的粒度越小，首次放电容量越大，且活化速度越快，但其饱和容量（活化后稳定的放电容量）随粒度的增大而增加，且在某个最佳粒度时达到最大值，然后又逐渐降低；该合金的高倍率放电容量与其粒度之间也有相同的规律，只是在不同的放电电流下最佳粒度值不同，当放电电流小于600mA/g时，30μm-76μm合金粉的放电容量最大，当放电电流等于或大于600mA/g时，40μm-50μm合金粉的放电容量最大；放电电流越大，颗粒度对合金粉电化学性能的影响越显著；在放电电流为300mA/g时，除30μm以下的合金粉性能衰减较快外，其余各个粒度的合金粉的性能衰减速度几乎相等；均匀的粒度分布有利于合金粉电化学性能的提高。
2001(4):310-313.
Abstract:
采用SHS还原法以CaWO4,Mg粉为原料制备钨粉。研究了CaWO4-Mg合成过程中的物理化学变化，压坯压力、稀释剂和浸出对燃烧过程和产物的影响。随着压坯压力的增加，燃烧产物的空隙率和钨粉颗粒的粒度呈递减趋势。添加稀释剂（钨粉），钨粉颗粒的粒度有所增大。通过进一步碱浸可提高钨粉的纯度。最终产物的成分光谱分析和粒度分析结果表明：可得到平均粒径为0．87μm，比表面积1．09m^2/g，纯度≥99．0％的钨粉。
采用SHS还原法以CaWO4,Mg粉为原料制备钨粉。研究了CaWO4-Mg合成过程中的物理化学变化，压坯压力、稀释剂和浸出对燃烧过程和产物的影响。随着压坯压力的增加，燃烧产物的空隙率和钨粉颗粒的粒度呈递减趋势。添加稀释剂（钨粉），钨粉颗粒的粒度有所增大。通过进一步碱浸可提高钨粉的纯度。最终产物的成分光谱分析和粒度分析结果表明：可得到平均粒径为0．87μm，比表面积1．09m^2/g，纯度≥99．0％的钨粉。
2001(4):314-317.
Abstract:
采用电子束物理气相沉积（EB－PVD）方法在DZ22合金基体上沉积制得了在NiCoCrA1Y粘结层和YSZ（Yt-tria Stabilized Zirconia)陶瓷顶层组成的双层结构的热障涂层。研究了NiCoCrA1Y粘结层表面的喷丸强化处理对热障涂层的抗氧化性能的影响，利用MTS测试了经等温氧化不同时间后的热障涂层内部的结合强度，并采用SEM和XRD观察和分析了涂层的界面结合以及相组成。结果表明，等温氧化后热障涂层内部的结合强度急剧降低，在位伸和剪切应力作用下，涂层沿着TGO（Thermally Grown Oxide）层内部断裂失效，强度为0．3MPa的表面喷丸处理能显著提高热障涂层的抗氧化性能和涂层内部TGO层的结合强度。
采用电子束物理气相沉积（EB－PVD）方法在DZ22合金基体上沉积制得了在NiCoCrA1Y粘结层和YSZ（Yt-tria Stabilized Zirconia)陶瓷顶层组成的双层结构的热障涂层。研究了NiCoCrA1Y粘结层表面的喷丸强化处理对热障涂层的抗氧化性能的影响，利用MTS测试了经等温氧化不同时间后的热障涂层内部的结合强度，并采用SEM和XRD观察和分析了涂层的界面结合以及相组成。结果表明，等温氧化后热障涂层内部的结合强度急剧降低，在位伸和剪切应力作用下，涂层沿着TGO（Thermally Grown Oxide）层内部断裂失效，强度为0．3MPa的表面喷丸处理能显著提高热障涂层的抗氧化性能和涂层内部TGO层的结合强度。
Zheng Guoqing
,
Ren Huping
,
Kou Xiandong
,
Wang Jian
,
Zheng Guoxi
,
Chan Heiuen
,
Zhang Ping
,
Chan Yuping
2001(4):318-319.
Abstract:
采用钛材研制了可返转的婴幼儿胸骨、肋骨牵开器。此器件由齿条板、固定臂、活动臂、拨轮、摇柄把、带弧度可返转的档板组成。经100家医院在心脏直视手术室间隔缺损、房间隔缺损、法乐氏四联症、部分心内膜垫缺损、动脉导管未闭结扎等先天性心脏病手术中临床应用获得满意效果。
采用钛材研制了可返转的婴幼儿胸骨、肋骨牵开器。此器件由齿条板、固定臂、活动臂、拨轮、摇柄把、带弧度可返转的档板组成。经100家医院在心脏直视手术室间隔缺损、房间隔缺损、法乐氏四联症、部分心内膜垫缺损、动脉导管未闭结扎等先天性心脏病手术中临床应用获得满意效果。
