Volume 36,Issue 1,2007 Table of Contents
2007, 36(1).
Abstract:
采用循环伏安法和计时电流法研究了700℃时LiF-NaF-KF-K2TiF6熔盐中Ti(IV)在铂电极上阴极电化学还原机理以及电结晶过程。结果表明:Ti(IV)的电化学还原机理为三步骤电荷传递反应:Ti(IV)+e→Ti(III);Ti(III)+2e→Ti(I);Ti(I)+e→Ti(0),且阴极过程可逆;电结晶过程为瞬时形核。
采用循环伏安法和计时电流法研究了700℃时LiF-NaF-KF-K2TiF6熔盐中Ti(IV)在铂电极上阴极电化学还原机理以及电结晶过程。结果表明:Ti(IV)的电化学还原机理为三步骤电荷传递反应:Ti(IV)+e→Ti(III);Ti(III)+2e→Ti(I);Ti(I)+e→Ti(0),且阴极过程可逆;电结晶过程为瞬时形核。
2 A Study of Hot Deformation Mechanisms in Ti-40 Burn Resistant Titanium Alloy Using Processing Maps
2007, 36(1):1-6.
Abstract:
采用热模拟压缩试验研究了Ti-40阻燃钛合金在温度900℃～1100℃、应变速率0．01s^-1～10s^-1范围内的高温变形特性，发现合金的流动应力-应变曲线具订应力峰和流变软化特征，在高温、高应变速率下，出现小连续屈服现象。根据动态材料模型（DMM）建立的Ti-40合金加工图大致可以分为5个区域：（1）在温度900℃-950℃，应变速率大于1s。时，易发生45°角剪切开裂，出现明显的剪切变形带，功率耗散率达最小值。（2）在温度1000℃～1100℃、应变速率人于1s^-1时，易出现“豆腐渣”式和纵向开裂，大变形时出现局部塑性流动。这2个区域为流动失稳区，在制定热加工工艺时应尽量避免。（3）在高温（≥1050℃）、低应变速率区（≤0．1s^-1），功率耗散率为46％-76％，达到盛大值，呈现连续冉结晶的特征。（4）在900℃-950℃、应变速率0．01s^-1～0．1s^-1区域内主要发生动态回复，功率耗散率为22％-32％。（5）在温度950℃～1050℃、应变速率0.1s^-1～1s^-1范用为再结晶区域，功率耗散率为36％～50％。结果表明，加工图是控制材料组织演变和优化工艺的一种有效手段。
采用热模拟压缩试验研究了Ti-40阻燃钛合金在温度900℃～1100℃、应变速率0．01s^-1～10s^-1范围内的高温变形特性，发现合金的流动应力-应变曲线具订应力峰和流变软化特征，在高温、高应变速率下，出现小连续屈服现象。根据动态材料模型（DMM）建立的Ti-40合金加工图大致可以分为5个区域：（1）在温度900℃-950℃，应变速率大于1s。时，易发生45°角剪切开裂，出现明显的剪切变形带，功率耗散率达最小值。（2）在温度1000℃～1100℃、应变速率人于1s^-1时，易出现“豆腐渣”式和纵向开裂，大变形时出现局部塑性流动。这2个区域为流动失稳区，在制定热加工工艺时应尽量避免。（3）在高温（≥1050℃）、低应变速率区（≤0．1s^-1），功率耗散率为46％-76％，达到盛大值，呈现连续冉结晶的特征。（4）在900℃-950℃、应变速率0．01s^-1～0．1s^-1区域内主要发生动态回复，功率耗散率为22％-32％。（5）在温度950℃～1050℃、应变速率0.1s^-1～1s^-1范用为再结晶区域，功率耗散率为36％～50％。结果表明，加工图是控制材料组织演变和优化工艺的一种有效手段。
2007, 36(1):7-10.
Abstract:
以TiN和NiCrBSi合金混合粉末为原料，采用激光熔覆技术在TC4合金表面制备出TiN颗粒增强Ni基合金涂层。利用XRD，SEM和TEM等分析了激光熔覆层的相组成及微观组织，并测试了激光熔覆层的显微硬度和磨损性能。结果表明，激光熔覆层由熔覆区和稀释区2个区域组成，熔覆区的组织是在γ-Ni树枝晶和γ-Ni＋Ni3B层片状共晶的基体上均匀地分布着TiN颗粒和针状尬3C6相，显微硬度在9000MPa-12000MPa之间.稀释区为基底TC4合金和熔覆材料Ni基合金的混合凝固区，呈胞状晶和树枝晶形态。激光熔覆层中存在颗粒强化、细晶强化和固溶强化等多种强化作用，大幅度地提高了TC4合金的耐磨性能。
以TiN和NiCrBSi合金混合粉末为原料，采用激光熔覆技术在TC4合金表面制备出TiN颗粒增强Ni基合金涂层。利用XRD，SEM和TEM等分析了激光熔覆层的相组成及微观组织，并测试了激光熔覆层的显微硬度和磨损性能。结果表明，激光熔覆层由熔覆区和稀释区2个区域组成，熔覆区的组织是在γ-Ni树枝晶和γ-Ni＋Ni3B层片状共晶的基体上均匀地分布着TiN颗粒和针状尬3C6相，显微硬度在9000MPa-12000MPa之间.稀释区为基底TC4合金和熔覆材料Ni基合金的混合凝固区，呈胞状晶和树枝晶形态。激光熔覆层中存在颗粒强化、细晶强化和固溶强化等多种强化作用，大幅度地提高了TC4合金的耐磨性能。
2007, 36(1):11-14.
Abstract:
研究了工业纯钛TA2室温下蠕变第1阶段的特性。结果表明，TA2材料室温下确实存在明显的蠕变现象，并且存在一个临界应力值，低于该临界值的TA2在室温下不会发生蠕变。TA2室温下蠕变第1阶段的规律为卢蠕变。针对TA2材料室温下第1阶段的蠕变特性，本研究提出了一种新的卢值与应力间的关系表达式：β=β0（σ-σ）c^m。其中σc。为蠕变临界应力。并且得到室温下TA2的蠕变临界应力值为267．25MPa。
研究了工业纯钛TA2室温下蠕变第1阶段的特性。结果表明，TA2材料室温下确实存在明显的蠕变现象，并且存在一个临界应力值，低于该临界值的TA2在室温下不会发生蠕变。TA2室温下蠕变第1阶段的规律为卢蠕变。针对TA2材料室温下第1阶段的蠕变特性，本研究提出了一种新的卢值与应力间的关系表达式：β=β0（σ-σ）c^m。其中σc。为蠕变临界应力。并且得到室温下TA2的蠕变临界应力值为267．25MPa。
2007, 36(1):23-27.
Abstract:
To understand the characteristics of extruded, forged and annealed tantalum(Ta), the chemical composition, hardness and microstructure of Ta in each working process are measured. Mechanical performance of Ta after each working process was studied. The thermomechanical responses of forged and annealed Ta were investigated at different temperatures and different strain rates, using Instron servohydraulic testing machine and the split Hopkinson compression bar. Results show: (1) elements O and C in as-extruded Ta were 30% higher than those in Ta powder, but element of N was 50% lower than that of powder; (2) as-extruded Ta was forged and annealed at 1523 K for 2 h, complete recrystalization occured. Grain number and hardness of Ta disk changed from center to edge; (3) the mechanical performance in certer of the Ta disk showed remarkably anisotropy, this phenomenon appeared slightly at edge of the disk. Finally, Based on mechanism of thermal activation glide of dislocation, and physical concept of plastic deformation, a constitutive modeling was deduced to predict palstic flow stress of Ta. Modeling results were compared with the results of Johnson-Cook modeling and experimental results. The results show that the present dynamic constitutive modeling can make a satisified predication to the plastic flow seress.
To understand the characteristics of extruded, forged and annealed tantalum(Ta), the chemical composition, hardness and microstructure of Ta in each working process are measured. Mechanical performance of Ta after each working process was studied. The thermomechanical responses of forged and annealed Ta were investigated at different temperatures and different strain rates, using Instron servohydraulic testing machine and the split Hopkinson compression bar. Results show: (1) elements O and C in as-extruded Ta were 30% higher than those in Ta powder, but element of N was 50% lower than that of powder; (2) as-extruded Ta was forged and annealed at 1523 K for 2 h, complete recrystalization occured. Grain number and hardness of Ta disk changed from center to edge; (3) the mechanical performance in certer of the Ta disk showed remarkably anisotropy, this phenomenon appeared slightly at edge of the disk. Finally, Based on mechanism of thermal activation glide of dislocation, and physical concept of plastic deformation, a constitutive modeling was deduced to predict palstic flow stress of Ta. Modeling results were compared with the results of Johnson-Cook modeling and experimental results. The results show that the present dynamic constitutive modeling can make a satisified predication to the plastic flow seress.
2007, 36(1):28-31.
Abstract:
In order to increase the density of W-Ni-Mn alloy, some alloying elements were added into W-Ni-Mn alloy for improving sintering characteristics. SEM and EDS were used to study the microstructure of sintered W-Ni-Mn alloy. The results show that MnO can be deoxidized by aluminum and silicon, to purify the binder phase;Zn and Sn can reduce the sintering temperature. The two approaches improve the density of W-Ni-Mn alloy.
In order to increase the density of W-Ni-Mn alloy, some alloying elements were added into W-Ni-Mn alloy for improving sintering characteristics. SEM and EDS were used to study the microstructure of sintered W-Ni-Mn alloy. The results show that MnO can be deoxidized by aluminum and silicon, to purify the binder phase;Zn and Sn can reduce the sintering temperature. The two approaches improve the density of W-Ni-Mn alloy.
2007, 36(1):32-36.
Abstract:
以SmCl3为原料，硼氢化钠为还原剂，低代（2．0G3．0G,4．0G）PAMAM树形分子为模板兼稳定剂、制备出纳米颗粒。实验发现，其他条件相同时，树形分子代数越高，所起的模板作用越显著，即Sm／4．0GPAMAM的复合纳米颗粒粒度均匀，分散度好。应用Virtual Materiale（VM）软件对Sm／PAMAM纳米颗粒进行分子动力学模拟。从分子结构和能量变化角度研究了正则（恒定的NVT）系中复合体系的稳定性及其机理。分子动力学模拟结果显示：4．0GPAMAM更适合于作为模板剂和稳定剂，表明动力学模拟结论与实验结果一致。
以SmCl3为原料，硼氢化钠为还原剂，低代（2．0G3．0G,4．0G）PAMAM树形分子为模板兼稳定剂、制备出纳米颗粒。实验发现，其他条件相同时，树形分子代数越高，所起的模板作用越显著，即Sm／4．0GPAMAM的复合纳米颗粒粒度均匀，分散度好。应用Virtual Materiale（VM）软件对Sm／PAMAM纳米颗粒进行分子动力学模拟。从分子结构和能量变化角度研究了正则（恒定的NVT）系中复合体系的稳定性及其机理。分子动力学模拟结果显示：4．0GPAMAM更适合于作为模板剂和稳定剂，表明动力学模拟结论与实验结果一致。
2007, 36(1):37-41.
Abstract:
以锻造CoNiCrMo，CoCrMo和CoCrMoC台会为研究对象，通过金相观察，XRD分析和耐腐蚀试验，研究了3组合金在不同热处理条件下的显微结构，相成分及在Hi同溶液中的耐腐蚀性能。结果表明：2组锻造合金的再结晶温度都是1000℃，且晶粒尺寸随着固溶温度升高和时效时间延长而逐渐变大。3组试样在NaCl溶液中为钴基合金典型的阳极极化曲线；在Hanks’溶液中均有一个二次钝化行为，且锻造CoNiCrMo合金的二次钝化区域较窄，而其他2组合金则较宽；在含柠檬酸三钠的溶液中过钝化电位降低，柠檬酸盐的存在降低了含金的耐腐蚀性能。热处理对合金的耐腐蚀性能影响不大。
以锻造CoNiCrMo，CoCrMo和CoCrMoC台会为研究对象，通过金相观察，XRD分析和耐腐蚀试验，研究了3组合金在不同热处理条件下的显微结构，相成分及在Hi同溶液中的耐腐蚀性能。结果表明：2组锻造合金的再结晶温度都是1000℃，且晶粒尺寸随着固溶温度升高和时效时间延长而逐渐变大。3组试样在NaCl溶液中为钴基合金典型的阳极极化曲线；在Hanks’溶液中均有一个二次钝化行为，且锻造CoNiCrMo合金的二次钝化区域较窄，而其他2组合金则较宽；在含柠檬酸三钠的溶液中过钝化电位降低，柠檬酸盐的存在降低了含金的耐腐蚀性能。热处理对合金的耐腐蚀性能影响不大。
2007, 36(1):42-45.
Abstract:
研究了K465高温合金在850℃←→20℃,950℃←→20℃，1000℃←→20℃和1050℃←→20℃←冷热循环过程中碳化物的析出情况。在850℃←→20℃冷热循环过程中，没有发现析出犁碳化物；在950℃←→20℃冷热循环过程中，在枝晶间析出了M6C碳化物；在1000℃←→20℃和1050℃←→20℃冷热循环过程中，在枝晶间和枝晶千同时析出了方块状、短杆状、颗粒状和针状M6C碳化物。与等温热处理相比，冷热循环作用明显促进M6C碳化物的析出。此外，提高冷热循环的上限温度加速M6C碳化物的析出。
研究了K465高温合金在850℃←→20℃,950℃←→20℃，1000℃←→20℃和1050℃←→20℃←冷热循环过程中碳化物的析出情况。在850℃←→20℃冷热循环过程中，没有发现析出犁碳化物；在950℃←→20℃冷热循环过程中，在枝晶间析出了M6C碳化物；在1000℃←→20℃和1050℃←→20℃冷热循环过程中，在枝晶间和枝晶千同时析出了方块状、短杆状、颗粒状和针状M6C碳化物。与等温热处理相比，冷热循环作用明显促进M6C碳化物的析出。此外，提高冷热循环的上限温度加速M6C碳化物的析出。
10 Microstructure Evolution and Analysis of a Single Crystal Ni-Based Superalloy during Heat Treatment
2007, 36(1):46-49.
Abstract:
通过对一种单晶镍基合金的差热曲线分析和不同条件热处理后的组织形貌观察，结合有限元分析，研究了合金中‘γ’相在热处理期间的组织演化规律。结果表明：实验用合金的热处理‘窗口’是48℃，在1300℃γ，相有最大的溶解速度，1040℃析出的γ’相最为稳定；确定出该合金的热处理工艺为1280℃，4h，AC＋1300℃，4h，AC＋1040℃，4h，AC＋870℃．24h,AC.一次时效期间，在界面能和共格应变能的作用下，γ’相长大呈立方体形貌；二次时效期间。γ’相略有长大，立方度增加，排列更加规则。其中，时效期间，共格界面的γ’相按“台阶机制”优先沿（100）取向扩散生长呈立方体形貌，而晶格错配应力的对称分布是使立方γ’相得以稳定存在的主要原因。
通过对一种单晶镍基合金的差热曲线分析和不同条件热处理后的组织形貌观察，结合有限元分析，研究了合金中‘γ’相在热处理期间的组织演化规律。结果表明：实验用合金的热处理‘窗口’是48℃，在1300℃γ，相有最大的溶解速度，1040℃析出的γ’相最为稳定；确定出该合金的热处理工艺为1280℃，4h，AC＋1300℃，4h，AC＋1040℃，4h，AC＋870℃．24h,AC.一次时效期间，在界面能和共格应变能的作用下，γ’相长大呈立方体形貌；二次时效期间。γ’相略有长大，立方度增加，排列更加规则。其中，时效期间，共格界面的γ’相按“台阶机制”优先沿（100）取向扩散生长呈立方体形貌，而晶格错配应力的对称分布是使立方γ’相得以稳定存在的主要原因。
11 The Effect of Preset Heating Rate on Combustion Synthesis of Fe-V-C System under an Electric Field
2007, 36(1):50-53.
Abstract:
采用Gleeble热模拟机研究了预设升温速度对Fe-V-C体系在电场作甩下燃烧合成的影响。用X射线衍射仪（XRD）以及扫描电镜（SEM）等研究了试样在不同预设升温速度下的相结构和显微组织。结果表明：在电场作用下，该体系的反应起始温度较低。预设升温速度对体系的影响呈阶段变化，当预设升温速度为600℃／s-1000℃／s时，合成过程以及合成产物的变化不大：当预设升温速度升至1400℃／s时，体系的点火温度降低、点火延迟时间缩短，合成产物颗粒变小，硬度提高。
采用Gleeble热模拟机研究了预设升温速度对Fe-V-C体系在电场作甩下燃烧合成的影响。用X射线衍射仪（XRD）以及扫描电镜（SEM）等研究了试样在不同预设升温速度下的相结构和显微组织。结果表明：在电场作用下，该体系的反应起始温度较低。预设升温速度对体系的影响呈阶段变化，当预设升温速度为600℃／s-1000℃／s时，合成过程以及合成产物的变化不大：当预设升温速度升至1400℃／s时，体系的点火温度降低、点火延迟时间缩短，合成产物颗粒变小，硬度提高。
2007, 36(1):54-58.
Abstract:
The static magnetic characteristics and microstructures of FeCuNbSiB fibres fabricated by the melt spun process, have been studied in this paper. The electromagnetic parameters (relative complex permittivity and permeability) of the composite have been also investigated using fibres heat treated at 673 K for 1 h in X band (8.2 GHz~12.4 GHz). In the range of 2 GHz~4 GHz, the effect of the content of the randomly oriented fibres in the composites (fibres + spherical magnetic particles + epoxy) on the electromagnetic parameters has been studied. The results show that the electromagnetic parameters can be improved effectively with an appropriate content of FeCuNbSiB fibres.
The static magnetic characteristics and microstructures of FeCuNbSiB fibres fabricated by the melt spun process, have been studied in this paper. The electromagnetic parameters (relative complex permittivity and permeability) of the composite have been also investigated using fibres heat treated at 673 K for 1 h in X band (8.2 GHz~12.4 GHz). In the range of 2 GHz~4 GHz, the effect of the content of the randomly oriented fibres in the composites (fibres + spherical magnetic particles + epoxy) on the electromagnetic parameters has been studied. The results show that the electromagnetic parameters can be improved effectively with an appropriate content of FeCuNbSiB fibres.
2007, 36(1):59-62.
Abstract:
借助光学显微镜、扫描电镜、X射线衍射仪和万能拉伸测试仪研究了AM60合金中加入RE和B后的组织和性能，并分析了RE和B对合金组织和性能的影响。结果表明，RE和B都可以使合金的晶粒细化。芦相的分布也变得均匀弥散，显著改善合金的显微组织，B和RE的同时加入效果最佳。0.15％（质量分数，下同）B加入AM60合金中没有形成新相，1．6％的RE加入则形成了稳定性较高的针状Al11RE3等相，B的变质作用及适当的周溶处理能使针状的稀土相钝化并变短。同时加入RE，B使合金的力学性能得到较显著的改善，其中显微硬度提高了26％，抗拉强度提高了20％。
借助光学显微镜、扫描电镜、X射线衍射仪和万能拉伸测试仪研究了AM60合金中加入RE和B后的组织和性能，并分析了RE和B对合金组织和性能的影响。结果表明，RE和B都可以使合金的晶粒细化。芦相的分布也变得均匀弥散，显著改善合金的显微组织，B和RE的同时加入效果最佳。0.15％（质量分数，下同）B加入AM60合金中没有形成新相，1．6％的RE加入则形成了稳定性较高的针状Al11RE3等相，B的变质作用及适当的周溶处理能使针状的稀土相钝化并变短。同时加入RE，B使合金的力学性能得到较显著的改善，其中显微硬度提高了26％，抗拉强度提高了20％。
2007, 36(1):68-70.
Abstract:
By using a Scanning Electron Microscope (SEM), the tracks of cathode spots on the surface of nanocrystalline Cu cathode produced after the first discharge with peak current of 10 A was investigated. It is found that the movement of cathode spots is sub-directed rather than random. The reason is explained in comparison with conventional Cu. It is suggested that sub-directed walking of cathode spots on the surface of nanocrystalline Cu is beneficial to the diffusion of cathode spots which is responsible for cathode erosion.
By using a Scanning Electron Microscope (SEM), the tracks of cathode spots on the surface of nanocrystalline Cu cathode produced after the first discharge with peak current of 10 A was investigated. It is found that the movement of cathode spots is sub-directed rather than random. The reason is explained in comparison with conventional Cu. It is suggested that sub-directed walking of cathode spots on the surface of nanocrystalline Cu is beneficial to the diffusion of cathode spots which is responsible for cathode erosion.
2007, 36(1):71-74.
Abstract:
利用电化学极化曲线和阻抗图谱（EIS）技术研究了Pr60Fe30Al10块体非晶及其晶化后合金在不同pH值的3．5％（质量分数，下同）NaCl溶液中的腐蚀行为。结果发现，随着pH值的增大2种合金的耐蚀性都增强。即在开路电位Ecorr下，腐蚀电流icorr减小，Ecorr向贵金属方向变化，极化电阻Rp及相应的阻抗图谱等效电阻R＇p增大；当pH值一定时，非晶合金和晶化后台金相比，非晶合金的阳极极化曲线出现了宽的钝化区，EIS Nyquist图谱呈现出更大的容抗弧幅值，从而表现出强的耐蚀性。由极化曲线和交流阻抗技术所得到的极化电阻及腐蚀电流具有很好的一致性。
利用电化学极化曲线和阻抗图谱（EIS）技术研究了Pr60Fe30Al10块体非晶及其晶化后合金在不同pH值的3．5％（质量分数，下同）NaCl溶液中的腐蚀行为。结果发现，随着pH值的增大2种合金的耐蚀性都增强。即在开路电位Ecorr下，腐蚀电流icorr减小，Ecorr向贵金属方向变化，极化电阻Rp及相应的阻抗图谱等效电阻R＇p增大；当pH值一定时，非晶合金和晶化后台金相比，非晶合金的阳极极化曲线出现了宽的钝化区，EIS Nyquist图谱呈现出更大的容抗弧幅值，从而表现出强的耐蚀性。由极化曲线和交流阻抗技术所得到的极化电阻及腐蚀电流具有很好的一致性。
2007, 36(1):75-77.
Abstract:
Amorphous nickel hydroxide powder was prepared successfully by the method of micro emulsion deepfreeze deposition. Using tiny electrode of sample powder as researching electrode, Pt as assistant electrode and Hg-HgO as referenced electrode, we tested the polarization curve of amorphous Ni(OH)2 powder and calculated j0 and jd. The resalt showed that the number of electron exchange on charging and discharging was 1.35 according to our approximate calculation, and its theoretical discharge capacity was 393.26 mAh/g, so it has high electrochemical capacity.
Amorphous nickel hydroxide powder was prepared successfully by the method of micro emulsion deepfreeze deposition. Using tiny electrode of sample powder as researching electrode, Pt as assistant electrode and Hg-HgO as referenced electrode, we tested the polarization curve of amorphous Ni(OH)2 powder and calculated j0 and jd. The resalt showed that the number of electron exchange on charging and discharging was 1.35 according to our approximate calculation, and its theoretical discharge capacity was 393.26 mAh/g, so it has high electrochemical capacity.
2007, 36(1):78-81.
Abstract:
Through analysis of the hydriding/dehydriding process of hydrogen storage material, an apparatus for measuring hydrogen storage properties was designed and set up. This apparatus can be employed to measure the curves of the hydriding/dehydriding dynamics, the PCT curves and the cycle life for hydrogen storage material. The hydriding/dehydriding properties of LaNis was acquired by this apparatus. The result indicates that this design principle of apparatus is reasonable; LaNi5 has excellent hydriding kinetics properties however, the cycle life is rather bad because of quite fast capacity decrease after 60 ab-/desorption cycles.
Through analysis of the hydriding/dehydriding process of hydrogen storage material, an apparatus for measuring hydrogen storage properties was designed and set up. This apparatus can be employed to measure the curves of the hydriding/dehydriding dynamics, the PCT curves and the cycle life for hydrogen storage material. The hydriding/dehydriding properties of LaNis was acquired by this apparatus. The result indicates that this design principle of apparatus is reasonable; LaNi5 has excellent hydriding kinetics properties however, the cycle life is rather bad because of quite fast capacity decrease after 60 ab-/desorption cycles.
2007, 36(1):82-85.
Abstract:
研究了氕和氘在Pd-8％Y（原子分数，下同）合金膜中的渗透性能，预测了一定条件下以该合金管为分离膜材料的钯合金膜分离器对氕和氘的分离性能。结果表明：在573K-873K，0．0SMPa-0．40MPa下，氕和氘的渗透通量与压力的平方根成正比，氕和氘的渗透率与温度之间满足阿伦尼乌斯公式；渗透通量与压力数据J=ФAmP^n/tm拟合时。n在0.66左右，表明对于装置所用厚度的钯合金膜。表面过程对氕和氘的渗透率有很大影响；在该温度和压力范围内，如果忽略同位素之间的相互作用，钯合金膜分离器对1：1的氕和氘的分离系数在1，45～1．76之间，分离系数随温度的增高而减小。
研究了氕和氘在Pd-8％Y（原子分数，下同）合金膜中的渗透性能，预测了一定条件下以该合金管为分离膜材料的钯合金膜分离器对氕和氘的分离性能。结果表明：在573K-873K，0．0SMPa-0．40MPa下，氕和氘的渗透通量与压力的平方根成正比，氕和氘的渗透率与温度之间满足阿伦尼乌斯公式；渗透通量与压力数据J=ФAmP^n/tm拟合时。n在0.66左右，表明对于装置所用厚度的钯合金膜。表面过程对氕和氘的渗透率有很大影响；在该温度和压力范围内，如果忽略同位素之间的相互作用，钯合金膜分离器对1：1的氕和氘的分离系数在1，45～1．76之间，分离系数随温度的增高而减小。
2007, 36(1):86-90.
Abstract:
利用直流磁控溅射方法在柔性聚酯薄膜衬底上制备了氧化铟锡（ITO）透明导电薄膜，采用X射线衍射、紫外．可见分光光度计、四探针电阻测量仪等测试手段对薄膜样品进行表征，研究了氧含量、薄膜厚度、村底负偏压对ITO薄膜的晶体结构和光电性能的影响，优化了柔性衬底ITO薄膜的制备工艺条件。制得样品的最佳可见光平均透过率为85．6％，方块电阻为6Ω／口。
利用直流磁控溅射方法在柔性聚酯薄膜衬底上制备了氧化铟锡（ITO）透明导电薄膜，采用X射线衍射、紫外．可见分光光度计、四探针电阻测量仪等测试手段对薄膜样品进行表征，研究了氧含量、薄膜厚度、村底负偏压对ITO薄膜的晶体结构和光电性能的影响，优化了柔性衬底ITO薄膜的制备工艺条件。制得样品的最佳可见光平均透过率为85．6％，方块电阻为6Ω／口。
2007, 36(1):91-95.
Abstract:
采用水溶液恒电流电化学聚合法在纯钛表面制备了PPy涂层（Ti／PPy）。利用傅里叶红外光谱、X射线光电子能谱测定表面化学成分。用扫描电子显微镜观察涂层微观形貌，接触角测量仪检测接触角并计算表面能。搭接剪切法测定涂层与基底间的结合强度。通过对成骨细胞在Ti／PPy表面附着、铺展以及增殖能力的检测，评价Ti／PPy对成骨细胞生长的影响。结果表明，Ti／PPy的表面能（59．5mJ／m^2）高于纯钛（47．0mJ／m^2），并且具有良好的结合强度（9．16±1．62）MPa。Ti／PPy与Ti一样具有良好的生物相容性，成骨细胞能够在Ti／PPy涂层表面完成附着、铺展以及增殖的生物功能。
采用水溶液恒电流电化学聚合法在纯钛表面制备了PPy涂层（Ti／PPy）。利用傅里叶红外光谱、X射线光电子能谱测定表面化学成分。用扫描电子显微镜观察涂层微观形貌，接触角测量仪检测接触角并计算表面能。搭接剪切法测定涂层与基底间的结合强度。通过对成骨细胞在Ti／PPy表面附着、铺展以及增殖能力的检测，评价Ti／PPy对成骨细胞生长的影响。结果表明，Ti／PPy的表面能（59．5mJ／m^2）高于纯钛（47．0mJ／m^2），并且具有良好的结合强度（9．16±1．62）MPa。Ti／PPy与Ti一样具有良好的生物相容性，成骨细胞能够在Ti／PPy涂层表面完成附着、铺展以及增殖的生物功能。
2007, 36(1):96-99.
Abstract:
采用熔盐电解法，将掺杂CaCO3的TiO2烧结体（作为阴极），在900℃熔盐CaCl2中还原成金属钛。借助SEM，EDS及XRD分析了烧结后的阴极形貌、成分及相组成，考察CaCO3对电解提取钛反应的影响。结果表明：在TiO2阴极中掺杂CaCO3可以增加烧结后的阴极片孔隙度，并影响TiO2颗粒尺寸的大小，有利于加快阴极电解反应的速度，提高电解效率。
采用熔盐电解法，将掺杂CaCO3的TiO2烧结体（作为阴极），在900℃熔盐CaCl2中还原成金属钛。借助SEM，EDS及XRD分析了烧结后的阴极形貌、成分及相组成，考察CaCO3对电解提取钛反应的影响。结果表明：在TiO2阴极中掺杂CaCO3可以增加烧结后的阴极片孔隙度，并影响TiO2颗粒尺寸的大小，有利于加快阴极电解反应的速度，提高电解效率。
2007, 36(1):100-103.
Abstract:
High pure tungsten (W, 99.99%) were prepared by chemical vapor deposition (CVD), then high pure tungsten and polycrystalline tungsten prepared by powder metallurgy (PM) process were impacted using Split Hopkinson Bar (SHB) over a narrow range of strain rates, 1000 s-1~2000 s-1. The deformation mechanisms were analyzed by optical microscope (OM). The results show that the main deformation mechanisms of the polycrystalline tungsten prepared by Powder Metallurgy Process are slip and grain-boundary slide, while those of high pure tungsten are slip, twinning deformation and grain-boundary slide. The interaction between the neighbouring twinnings may induce two kinds of intergranular cracks, which is the key reason of the high pure tungsten em-brittleness. The adiabatic shear band (ASB) is not found for the high pure tungsten under the strain rate in this paper e.g. lower than 103 s-1, so the plastic deformation ability of the high pure tungsten can not be improved as that of tungsten heavy alloy (WHA).
High pure tungsten (W, 99.99%) were prepared by chemical vapor deposition (CVD), then high pure tungsten and polycrystalline tungsten prepared by powder metallurgy (PM) process were impacted using Split Hopkinson Bar (SHB) over a narrow range of strain rates, 1000 s-1~2000 s-1. The deformation mechanisms were analyzed by optical microscope (OM). The results show that the main deformation mechanisms of the polycrystalline tungsten prepared by Powder Metallurgy Process are slip and grain-boundary slide, while those of high pure tungsten are slip, twinning deformation and grain-boundary slide. The interaction between the neighbouring twinnings may induce two kinds of intergranular cracks, which is the key reason of the high pure tungsten em-brittleness. The adiabatic shear band (ASB) is not found for the high pure tungsten under the strain rate in this paper e.g. lower than 103 s-1, so the plastic deformation ability of the high pure tungsten can not be improved as that of tungsten heavy alloy (WHA).
2007, 36(1):104-107.
Abstract:
将Zr-Sn-Nb新锆合金样品分别进行多种变形热处理，用透射电子显微镜研究它们的显微组织和第二相粒子。然后把它们放入高压釜中，在350℃，16．8MPa，0．01mol／LLiOH水溶液中腐蚀。结果表明：580℃-3h／冷轧／500℃-30h处理的样品具有最好的耐腐蚀性能，这是因为该样品中Zr-Fe-Nb第二相粒子呈均匀细小分布，且体积分数在几种样品中最高，导致基体中的Nb元素同溶含量最低。
将Zr-Sn-Nb新锆合金样品分别进行多种变形热处理，用透射电子显微镜研究它们的显微组织和第二相粒子。然后把它们放入高压釜中，在350℃，16．8MPa，0．01mol／LLiOH水溶液中腐蚀。结果表明：580℃-3h／冷轧／500℃-30h处理的样品具有最好的耐腐蚀性能，这是因为该样品中Zr-Fe-Nb第二相粒子呈均匀细小分布，且体积分数在几种样品中最高，导致基体中的Nb元素同溶含量最低。
2007, 36(1):108-112.
Abstract:
La-Mg-Ni system (PuNi3-type) La0.7Mg0.3Ni2.55-xCo0.45Cux (x=0, 0.2, 0.4) hydrogen storage electrode alloys were prepared by casting and melt spinning process. The microstructure and electrochemical performances of the as-cast and melten spun alloys were analyzed and measured. The effects of substituting Ni with Cu and melt spinning on microstructures and electrochemical performances of the as-cast and melten spun alloys were investigated in detail. The obtained results show that the as-cast and melten spun alloys are composed of the (La, Mg)Ni3 phase and the LaNi5 phase as well as the LaNi2 phase. The melt spinning have an inappreciable influence on the phase compositions of the alloys, but leads to the homogeneity of the diffraction peaks of the alloys. The results obtained by the electrochemical measurement indicate that the substitution decreased the discharge capacities of the as-cast and melt spun alloys, whereas improved the cycle stability and discharge voltage characteristic of the as-cast and melten spun alloys. The melt spinning significantly improved the cycle stability of the alloys, but it notably decreased the discharge capacity of the alloys.
La-Mg-Ni system (PuNi3-type) La0.7Mg0.3Ni2.55-xCo0.45Cux (x=0, 0.2, 0.4) hydrogen storage electrode alloys were prepared by casting and melt spinning process. The microstructure and electrochemical performances of the as-cast and melten spun alloys were analyzed and measured. The effects of substituting Ni with Cu and melt spinning on microstructures and electrochemical performances of the as-cast and melten spun alloys were investigated in detail. The obtained results show that the as-cast and melten spun alloys are composed of the (La, Mg)Ni3 phase and the LaNi5 phase as well as the LaNi2 phase. The melt spinning have an inappreciable influence on the phase compositions of the alloys, but leads to the homogeneity of the diffraction peaks of the alloys. The results obtained by the electrochemical measurement indicate that the substitution decreased the discharge capacities of the as-cast and melt spun alloys, whereas improved the cycle stability and discharge voltage characteristic of the as-cast and melten spun alloys. The melt spinning significantly improved the cycle stability of the alloys, but it notably decreased the discharge capacity of the alloys.
2007, 36(1):113-116.
Abstract:
Different-rate rapid quenching was used in the preparation of low-Co AB5 hydrogen storage alloys in order to improve its electrochemical properties. The results show that proper quenching not only increased discharge capacity greatly but also can improved cycle stability and discharge voltage property. Adopting 18 m/s rapid quenching, the alloy can get better electrochemical properties. Mierostructure and phase structure of as-cast and quenched alloys were observed by XRD and SEM. The rapid quenching effects on the electrochemical properties of low-Co hydrogen storage alloy are discussed.
Different-rate rapid quenching was used in the preparation of low-Co AB5 hydrogen storage alloys in order to improve its electrochemical properties. The results show that proper quenching not only increased discharge capacity greatly but also can improved cycle stability and discharge voltage property. Adopting 18 m/s rapid quenching, the alloy can get better electrochemical properties. Mierostructure and phase structure of as-cast and quenched alloys were observed by XRD and SEM. The rapid quenching effects on the electrochemical properties of low-Co hydrogen storage alloy are discussed.
2007, 36(1):117-120.
Abstract:
以NH4VO3，LiCl2和NiCl2等为原料，以氨水为pH调节剂，采用超声凝胶方法制备了LiNiVO4纳米晶。并采用XRD，TEM，IR，DTA和TG等分析手段对产物进行了表征，通过差热分析对其合成活化能进行了研究。发现在超声功率为300W时，于500℃下保温1h，可以合成10nm左右的LiNiV04微晶颗粒，其合成活化能为47．7kJ／mol。电化学性能测试结果表明，在0．2mA／cm。充放电流密度和3．0V～4.8V电压范围内，首次充电容量为103mAh／g，放电容量为75mAh／g，循环次数达4次后，放电容量还有62mAh／g，明显优于目前所报道的同类材料。
以NH4VO3，LiCl2和NiCl2等为原料，以氨水为pH调节剂，采用超声凝胶方法制备了LiNiVO4纳米晶。并采用XRD，TEM，IR，DTA和TG等分析手段对产物进行了表征，通过差热分析对其合成活化能进行了研究。发现在超声功率为300W时，于500℃下保温1h，可以合成10nm左右的LiNiV04微晶颗粒，其合成活化能为47．7kJ／mol。电化学性能测试结果表明，在0．2mA／cm。充放电流密度和3．0V～4.8V电压范围内，首次充电容量为103mAh／g，放电容量为75mAh／g，循环次数达4次后，放电容量还有62mAh／g，明显优于目前所报道的同类材料。
2007, 36(1):121-125.
Abstract:
Based on thermodynamics and kinetics theory, a theoretical model to illuminate the process for preparing metal nanopowders by anodic arc discharging plasma method was set up, and the origin of plasma, metallic evaporation, the mechanism of particle nucleation and growth were investigated. The influences of various technology parameters on the properties of nanopowders by Anodic Arc Plasma were also discussed. In addition, the samples prepared by this method were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and the corresponding electron diffraction (ED) to determine the crystal structure, morphology, particle size and particle size distribution. The experimental results show that the crystal structure of the nanopowder sample is the same as the bulk material, being fcc structure, with an average size about 16 nm, distribution ranging from 10 nm to 40 nm. The technology parameters (such as the power supply, the pressure of gas, the arc current intensity, water-cooling condition, etc.) have great effect on the particle nucleation and growth, the particle size can be effectively controlled by varying the technological parameters.
Based on thermodynamics and kinetics theory, a theoretical model to illuminate the process for preparing metal nanopowders by anodic arc discharging plasma method was set up, and the origin of plasma, metallic evaporation, the mechanism of particle nucleation and growth were investigated. The influences of various technology parameters on the properties of nanopowders by Anodic Arc Plasma were also discussed. In addition, the samples prepared by this method were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and the corresponding electron diffraction (ED) to determine the crystal structure, morphology, particle size and particle size distribution. The experimental results show that the crystal structure of the nanopowder sample is the same as the bulk material, being fcc structure, with an average size about 16 nm, distribution ranging from 10 nm to 40 nm. The technology parameters (such as the power supply, the pressure of gas, the arc current intensity, water-cooling condition, etc.) have great effect on the particle nucleation and growth, the particle size can be effectively controlled by varying the technological parameters.
2007, 36(1):126-129.
Abstract:
在孔深60gm，直径200nm的通孔氧化铝模板中，用60mmol·dm^-3。Pd（NH3）4Cl2＋40mmol·dm^-3NiSO4·6H2O＋0．2mol·dm^-3NH4Cl，pH8．5和70mmol·dm^-3。Pd（NH3）4Cl2＋30mmol-dm^-3NiSO4·6H2O＋0．2mol·dm^-3NH4Cl，pH8.5的2种电解液，采用直流电沉积的方法制备钯镍合金纳米线阵列。借助扫描电子显微镜（SEM）和X-射线能谱仪（EDX）表征纳米线的形貌和成分。结果表明，用-0．6V～-0．8V（vsSCE）的直流电沉积，在氧化铝（AAO）模板中可以成功地制备出镍含量在8％～15％（质量分数，下同）之间的Pd-Ni合金纳米线有序阵列，其直径和模板的孔径是一致的。沉积电势负移将使得电流密度增加，有利于合金中电势较负金属镍含量的增大。
在孔深60gm，直径200nm的通孔氧化铝模板中，用60mmol·dm^-3。Pd（NH3）4Cl2＋40mmol·dm^-3NiSO4·6H2O＋0．2mol·dm^-3NH4Cl，pH8．5和70mmol·dm^-3。Pd（NH3）4Cl2＋30mmol-dm^-3NiSO4·6H2O＋0．2mol·dm^-3NH4Cl，pH8.5的2种电解液，采用直流电沉积的方法制备钯镍合金纳米线阵列。借助扫描电子显微镜（SEM）和X-射线能谱仪（EDX）表征纳米线的形貌和成分。结果表明，用-0．6V～-0．8V（vsSCE）的直流电沉积，在氧化铝（AAO）模板中可以成功地制备出镍含量在8％～15％（质量分数，下同）之间的Pd-Ni合金纳米线有序阵列，其直径和模板的孔径是一致的。沉积电势负移将使得电流密度增加，有利于合金中电势较负金属镍含量的增大。
2007, 36(1):130-133.
Abstract:
Nanocrystalline nickel and micro-grained nickel was prepared by pulse electrodeposition, and the corrosion behavior of electrolytic nickel, coarsed-grained nickel and nanocrystalline nickel in 3.5%NaCl solution and 10%HCl solution was studied by soak method and electrochemical polarization method, respectively. Three nickel samples all exhibited well corrosion resistance in 3.5%NaCl solution, however, nanocrystalline nickel was easier to be corroded due to the increase of fraction of interface volum. In 10%HCl solution they also showed good corrosion resistance, the nanocrystalline Ni presented the weakest corrosion resistance among the three nickel samples.
Nanocrystalline nickel and micro-grained nickel was prepared by pulse electrodeposition, and the corrosion behavior of electrolytic nickel, coarsed-grained nickel and nanocrystalline nickel in 3.5%NaCl solution and 10%HCl solution was studied by soak method and electrochemical polarization method, respectively. Three nickel samples all exhibited well corrosion resistance in 3.5%NaCl solution, however, nanocrystalline nickel was easier to be corroded due to the increase of fraction of interface volum. In 10%HCl solution they also showed good corrosion resistance, the nanocrystalline Ni presented the weakest corrosion resistance among the three nickel samples.
2007, 36(1):134-137.
Abstract:
采用醇还原的方法合成了聚阳离子（聚二烯丙基二甲基氯化铵，PDDA），颗粒的zeta电位为＋32mV，粒径约4nm。在静电引力作用下将聚阳离子修饰的金颗粒组装到Nafion^TM212膜表面制成抗甲醇渗透质子交换膜。在60℃，2mol／L的甲醇溶液中，甲醇渗透电流由168mA／cm^2下降到18mA／cm^2，其组装的单电池具有更好的开路电压和输出性能。
采用醇还原的方法合成了聚阳离子（聚二烯丙基二甲基氯化铵，PDDA），颗粒的zeta电位为＋32mV，粒径约4nm。在静电引力作用下将聚阳离子修饰的金颗粒组装到Nafion^TM212膜表面制成抗甲醇渗透质子交换膜。在60℃，2mol／L的甲醇溶液中，甲醇渗透电流由168mA／cm^2下降到18mA／cm^2，其组装的单电池具有更好的开路电压和输出性能。
2007, 36(1):138-140.
Abstract:
The Mg-Ni alloy was prepared by mechanical alloying. XRD and TEM analysis were used to indentify the microstructure and the phase of the Mg-Ni composite during the milling process, the thermodynamic properties of nanocrystalline Mg-Ni alloy were measured The results show that the alloy powder can be prepared by mechanical alloying on the condition that the milling technological parameters were strictly controled, The particle sizes of the powder were between 10 nm and 20 nm. At P-C isotherms there existed good plateau curves with long-width plateau.The nanocrystalline Mg-Ni alloy had a hystersis effect during hydrogen absorption/desorption and the effect decreased with the increase of temperature. The nanocrystalline Mg-Ni alloy has satisfied properties of hydrogen storage and a promising value of engineering application.
The Mg-Ni alloy was prepared by mechanical alloying. XRD and TEM analysis were used to indentify the microstructure and the phase of the Mg-Ni composite during the milling process, the thermodynamic properties of nanocrystalline Mg-Ni alloy were measured The results show that the alloy powder can be prepared by mechanical alloying on the condition that the milling technological parameters were strictly controled, The particle sizes of the powder were between 10 nm and 20 nm. At P-C isotherms there existed good plateau curves with long-width plateau.The nanocrystalline Mg-Ni alloy had a hystersis effect during hydrogen absorption/desorption and the effect decreased with the increase of temperature. The nanocrystalline Mg-Ni alloy has satisfied properties of hydrogen storage and a promising value of engineering application.
2007, 36(1):141-144.
Abstract:
采用粉体化学镀技术，以AgNO3取代常见的贵金属盐PdCl2作为活化剂、H2PO2取代Sn^2＋作为还原剂，经一步前处理过程，在空心微珠表面沉积NiCoP台金。利用扫描电镜、能谱分析仪以及X射线衍射分别讨论了沉积层的形貌、成分和相结构。结果表明：NiCoP合金均匀沉积在空心微珠表面；结合X射线光电子能谱仪观察到的银元素化学态的变化过程，提出了这种改进工艺的一种可能机理。
采用粉体化学镀技术，以AgNO3取代常见的贵金属盐PdCl2作为活化剂、H2PO2取代Sn^2＋作为还原剂，经一步前处理过程，在空心微珠表面沉积NiCoP台金。利用扫描电镜、能谱分析仪以及X射线衍射分别讨论了沉积层的形貌、成分和相结构。结果表明：NiCoP合金均匀沉积在空心微珠表面；结合X射线光电子能谱仪观察到的银元素化学态的变化过程，提出了这种改进工艺的一种可能机理。
2007, 36(1):145-148.
Abstract:
GdPO4:Eu3+ nanoparticles were prepared by precipitation method under different conditions with different pH, EDTA-2 Na and different annealing temperatures. The structure, morphology and luminescence characterization of GdPO4:Eu3+ nanoparticles were studied by XRD,SEM and luminescence spectrum. The results of XRD and SEM indicated that all of samples consisted of pure phase GdPO4:Eu3+, the size, and growth of crystal interface were related to synthesis conditions. The results of emission spectra and excitation spectra showed that the relative intensities of emission peaks increased with increasing of pH and annealing temperature, and the emission and excitation intensities of sample prepared with EDTA was lowered due to residual organic groups on the surface. The doping concentration of nanoparticles is about 8x%.
GdPO4:Eu3+ nanoparticles were prepared by precipitation method under different conditions with different pH, EDTA-2 Na and different annealing temperatures. The structure, morphology and luminescence characterization of GdPO4:Eu3+ nanoparticles were studied by XRD,SEM and luminescence spectrum. The results of XRD and SEM indicated that all of samples consisted of pure phase GdPO4:Eu3+, the size, and growth of crystal interface were related to synthesis conditions. The results of emission spectra and excitation spectra showed that the relative intensities of emission peaks increased with increasing of pH and annealing temperature, and the emission and excitation intensities of sample prepared with EDTA was lowered due to residual organic groups on the surface. The doping concentration of nanoparticles is about 8x%.
2007, 36(1):149-152.
Abstract:
采用水热法在160℃下合成了单相橄榄石结构的LiFePO4和LiFe0.95Ni0.05PO4。经550℃聚丙稀裂解碳包覆后得到LiFePO4／C的颗粒尺寸在200nm左右，碳包覆镍掺杂LiFe0.95Ni0.05PO4/C的颗粒尺寸在100nm以下。电化学测试结果表明：LiFePO4/C和LiFe0.95PO4／C的0．1C首次充放电可逆容量分别达到154mAh·g^-1和149mAh·g^-1，但掺镍的LiFe0.95Ni0．05PO4／C具有更优异的大电流充放电循环特性，0．5C和1C充放电100次后的放电容量分别达到147mAb·g^-1和134mAh·g^-1。
采用水热法在160℃下合成了单相橄榄石结构的LiFePO4和LiFe0.95Ni0.05PO4。经550℃聚丙稀裂解碳包覆后得到LiFePO4／C的颗粒尺寸在200nm左右，碳包覆镍掺杂LiFe0.95Ni0.05PO4/C的颗粒尺寸在100nm以下。电化学测试结果表明：LiFePO4/C和LiFe0.95PO4／C的0．1C首次充放电可逆容量分别达到154mAh·g^-1和149mAh·g^-1，但掺镍的LiFe0.95Ni0．05PO4／C具有更优异的大电流充放电循环特性，0．5C和1C充放电100次后的放电容量分别达到147mAb·g^-1和134mAh·g^-1。
2007, 36(1):153-156.
Abstract:
Using self-made semi-solid mechanical stirring process system, the solidification behavior of Pb-15wt% Sn alloy semi-solid slurry with solid fraction beyond 0.6 was investigated under stirring condition. A detailed microstructural analysis of the solid phase was carried out. The results show that the solid-liquid separation is obvious in the samples with the solid fraction beyond 0.6 and the solid phase is dispersed quasi-globular particles. Based on these results, a kind of single-crystal powders coated with Pb-Sn eutectic was made by continuous stirring and cooling under the semi-solid state and a new method for preparing metal powder is developed. The analysis and discussion indicate that this approach can reduce the content of oxide and impurity in the powder.
Using self-made semi-solid mechanical stirring process system, the solidification behavior of Pb-15wt% Sn alloy semi-solid slurry with solid fraction beyond 0.6 was investigated under stirring condition. A detailed microstructural analysis of the solid phase was carried out. The results show that the solid-liquid separation is obvious in the samples with the solid fraction beyond 0.6 and the solid phase is dispersed quasi-globular particles. Based on these results, a kind of single-crystal powders coated with Pb-Sn eutectic was made by continuous stirring and cooling under the semi-solid state and a new method for preparing metal powder is developed. The analysis and discussion indicate that this approach can reduce the content of oxide and impurity in the powder.
2007, 36(1):157-161.
Abstract:
The influence of sintering process on the density of nano-AgSnO2 composite was investigated using AgSnO2 powder prepared by electroless plating, adopting air sintering, hot pressing and vacuum sintering. The results show that density changed with compacting pressure, sintering temperature and sintering time when sintered in air, while the final density was close after repressing and resintering. For hot pressing, a density with higher than 96% could be achieved in a short time, but serious expansion and blistering ocurred. Vacuum sintering could help to wipe off adsorbates, but some residual still remained in the compact, and the expansion occurred during resintering. Low pressure compaction and step isothermal sintering could remove most of the adsorbates, and a high density of 94% was obtained after resintering. The large amount of absorbates on nano-AgSnO2 powder surface which led gases closed in the compact during sintering were found to be the main causes that affected densification process .
The influence of sintering process on the density of nano-AgSnO2 composite was investigated using AgSnO2 powder prepared by electroless plating, adopting air sintering, hot pressing and vacuum sintering. The results show that density changed with compacting pressure, sintering temperature and sintering time when sintered in air, while the final density was close after repressing and resintering. For hot pressing, a density with higher than 96% could be achieved in a short time, but serious expansion and blistering ocurred. Vacuum sintering could help to wipe off adsorbates, but some residual still remained in the compact, and the expansion occurred during resintering. Low pressure compaction and step isothermal sintering could remove most of the adsorbates, and a high density of 94% was obtained after resintering. The large amount of absorbates on nano-AgSnO2 powder surface which led gases closed in the compact during sintering were found to be the main causes that affected densification process .
2007, 36(1):162-165.
Abstract:
Sm-Co基整体辐向永磁环由于成型困难及烧结时易于变形和开裂等原因，限制了其应用和发展。为此，本文对Sm（Co，Fe，Cu，Zr）：整体辐向永磁环的烧结制备工艺，以及烧结和时效处理对磁体性能、组织结构的影响进行了研究。结果表明：调整合适的烧结工艺，能有效地抑制永磁环缺陷的产生，改善磁体的性能：在1220℃下烧结70min时磁体的性能较好，Br≥1．08T，Hcj≥2200kA／m，（BH）max≥214kJ／m^3；烧结磁体的矫顽力主要与时效工艺有关，时效前磁体主要是2：17型相的过饱和固溶体，在时效过程中析出1：5型相，并逐步形成胞状的显微组织结构，磁体的内禀矫顽力Hcj明显增加，在850℃时效8h，磁体的Hcj可达到2200kA／m以上。如果在850℃时效时间过长，胞状组织会被破坏，磁性能开始恶化。
Sm-Co基整体辐向永磁环由于成型困难及烧结时易于变形和开裂等原因，限制了其应用和发展。为此，本文对Sm（Co，Fe，Cu，Zr）：整体辐向永磁环的烧结制备工艺，以及烧结和时效处理对磁体性能、组织结构的影响进行了研究。结果表明：调整合适的烧结工艺，能有效地抑制永磁环缺陷的产生，改善磁体的性能：在1220℃下烧结70min时磁体的性能较好，Br≥1．08T，Hcj≥2200kA／m，（BH）max≥214kJ／m^3；烧结磁体的矫顽力主要与时效工艺有关，时效前磁体主要是2：17型相的过饱和固溶体，在时效过程中析出1：5型相，并逐步形成胞状的显微组织结构，磁体的内禀矫顽力Hcj明显增加，在850℃时效8h，磁体的Hcj可达到2200kA／m以上。如果在850℃时效时间过长，胞状组织会被破坏，磁性能开始恶化。
2007, 36(1):166-169.
Abstract:
An YBCO sample with high critical current density or single crystal stracture, can be obtained by the directional solidification method. In the present paper the morphology and chemical composition at the growth front of YB CO crystal have been investigate in order to it make clear the stopped growth mechanism of YBCO crystal growth during melt growth moment of the directional solidification. It is found that YBCO crystal will cease growing when yttrium and barium are depleted and copper becomes rich element in the liquid phase at the YBCO crystal growth front. For maintaining the continuous growth of YBCO, the composition of Y, Ba and Cu in raw sample has to be adjusted so as to make yttrium and barium enrichments in the liquid phase at the YBCO crystal growth front during the melt growth process.
An YBCO sample with high critical current density or single crystal stracture, can be obtained by the directional solidification method. In the present paper the morphology and chemical composition at the growth front of YB CO crystal have been investigate in order to it make clear the stopped growth mechanism of YBCO crystal growth during melt growth moment of the directional solidification. It is found that YBCO crystal will cease growing when yttrium and barium are depleted and copper becomes rich element in the liquid phase at the YBCO crystal growth front. For maintaining the continuous growth of YBCO, the composition of Y, Ba and Cu in raw sample has to be adjusted so as to make yttrium and barium enrichments in the liquid phase at the YBCO crystal growth front during the melt growth process.
2007, 36(1):170-173.
Abstract:
The microstructure and the corrosion property of AZ61 magnesium alloy stirred by permanent magnet (PM) were investigated. Based on the principle of electromagnetic field and magnetohydrodynamics, the force field of liquid metal in a PM field was analyzed. As a result, liquid metal in a PM experiences radial and tangential forces that are cyclically variational both in direction and magnitude. This phenomenon, namely electromagnetic vibration, influences matrix microstructure, subsequently affects corrosion property of the matrix.
The microstructure and the corrosion property of AZ61 magnesium alloy stirred by permanent magnet (PM) were investigated. Based on the principle of electromagnetic field and magnetohydrodynamics, the force field of liquid metal in a PM field was analyzed. As a result, liquid metal in a PM experiences radial and tangential forces that are cyclically variational both in direction and magnitude. This phenomenon, namely electromagnetic vibration, influences matrix microstructure, subsequently affects corrosion property of the matrix.
2007, 36(1):174-177.
Abstract:
采用原位合成技术成功制备了Ag／Y2O3和Ag／CeO2电接触材料。X射线衍射分析表明反应合成材料中的相是Ag和Y2O3，C2O2：BSE图像显示：稀土氧化物在基体中呈球状弥散分布，粒径约为0．1μm～0．4μm，界面清洁，内氧化层与基体结合良好，改善了增强相与基体浸润不良的问题，并使材料致密度得到提高。测量材料的物理性能和力学性能，发现2种氧化物对基体的影响基本趋于一致。分析氧化物的原位形核机制，认为是氧在基体金属中通过克服原子间势垒扩散进入合金内部，发生择优氧化。扩散的主要方式是体扩散，生成的增强相牢固地嵌入基体，使得该复合材料的界面结合紧，综合性能优良。
采用原位合成技术成功制备了Ag／Y2O3和Ag／CeO2电接触材料。X射线衍射分析表明反应合成材料中的相是Ag和Y2O3，C2O2：BSE图像显示：稀土氧化物在基体中呈球状弥散分布，粒径约为0．1μm～0．4μm，界面清洁，内氧化层与基体结合良好，改善了增强相与基体浸润不良的问题，并使材料致密度得到提高。测量材料的物理性能和力学性能，发现2种氧化物对基体的影响基本趋于一致。分析氧化物的原位形核机制，认为是氧在基体金属中通过克服原子间势垒扩散进入合金内部，发生择优氧化。扩散的主要方式是体扩散，生成的增强相牢固地嵌入基体，使得该复合材料的界面结合紧，综合性能优良。
2007, 36(1):178-183.
Abstract:
The research progress on the brittleness of the Laves NbCr2 compounds at ambient temperature is sumarrized. The embrittlement mechanism and several methods of improving toughness of NbCr2 are mainly introduced, such as grain refinement, alloying and soft phase toughening. Finally, the existing problems in these researches are put forward and the future research fields are suggested.
The research progress on the brittleness of the Laves NbCr2 compounds at ambient temperature is sumarrized. The embrittlement mechanism and several methods of improving toughness of NbCr2 are mainly introduced, such as grain refinement, alloying and soft phase toughening. Finally, the existing problems in these researches are put forward and the future research fields are suggested.
2007, 36(1):184-188.
Abstract:
The latest research status with respect to microstructures, properties and interface behavior of different particulate reinforced magnesium (PRM) matrix composites was reviewed. Based on the problems included in the study of PRM matrix composites, four research orientations in the future are suggested in the present paper, including the development of effective methods to control the interface behavior between reinforced particulates and matrices, the preparation methods of low cost to in-situ fabricate PRM matrix composites, the combination of different processing technologies, and the study of computer simulation technologies for strengthening and failure mechanisms of PRM.
The latest research status with respect to microstructures, properties and interface behavior of different particulate reinforced magnesium (PRM) matrix composites was reviewed. Based on the problems included in the study of PRM matrix composites, four research orientations in the future are suggested in the present paper, including the development of effective methods to control the interface behavior between reinforced particulates and matrices, the preparation methods of low cost to in-situ fabricate PRM matrix composites, the combination of different processing technologies, and the study of computer simulation technologies for strengthening and failure mechanisms of PRM.
