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Volume 36,Issue 8,2007 Table of Contents

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  • 1  Nodular Corrosion Resistance of Zr-Sn-Nb Alloy
    Zhou Bangxin Yao Meiyi Li Qiang Xia Shuang Liu Wenqing Chu Yuliang
    2007, 36(8):1317-1321.
    [Abstract](1561) [HTML](132) [PDF 0.00 Byte](1)
    Abstract:
    把N18(NZ2)锆合金样品经过多种不同的热处理后,用高压釜在500℃,10.3MPa过热蒸汽中进行腐蚀试验,研究了它们的耐疖状腐蚀性能。结果表明:无论是将样品加热到β相,α+β双相还是α相后,快冷还是缓冷,它们经过1100h腐蚀后都没有出现疖状腐蚀。说明在Zr-Sn合金中再添加合金元素Nb后,对疖状腐蚀产生了“免疫性”。样品在500℃过热蒸汽中的腐蚀增重动力学曲线仍可分为两个阶段,转折发生在氧化膜厚度大约为3μm时。
    2  Stress Distribution near Crack Tip for Beryllium Specimen under Compact Tension
    Dong Ping Li Ruiwen
    2007, 36(8):1322-1325.
    [Abstract](1224) [HTML](142) [PDF 0.00 Byte](2)
    Abstract:
    为了评估应力作用下铍试样裂纹尖端的微观断裂特性,设计了平面应变状态下铍的紧凑拉伸试样,采用X3000应力分析仪测试了不同载荷下铍试样裂纹尖端的应力分布,并对加载过程中铍试样内的应力应变进行了有限元计算。结果表明,离铍试样裂尖较远区域,有限元计算和实测值吻合较好,靠近裂尖区域,有限元计算高于实测值。根据铍试样拉伸时裂纹扩展的临界载荷,计算获得了铍试样裂纹尖端的最大应力、塑性区半径以及断裂强度因子。
    3  Characteristics of Oxidation Film on Ignition-proof Mg-3.5Y-0.8Ca Alloys at High Temperatures
    Fan Jianfeng Yang Gencang Zhou Yaohe Zhang Zhifeng Xu Jun Shi Likai
    2007, 36(8):1326-1330.
    [Abstract](1467) [HTML](133) [PDF 0.00 Byte](12)
    Abstract:
    A magnesium alloy with excellent ignition-proof property was acquired by adding yttrium and calcium at the same time. The Mg-3.SY-0.8Ca alloy could be immune from ignition at 1173 K for 30 min. XRD, SEM and AES analysis of oxide scale revealed that the oxide film formed on the surface of Mg-3.SY-0.SCa alloy was mainly composed of Y2O3. The Y2O3 film may be considered as an outstanding protective film due to its stable crystal structure, high melting point, low steam pressure, the P-B ratio more than 1, compact structure, low conductivity and excellent ductibility and so on.
    4  Influence of Heterogeneous Microstructure on the Plastic Behavior of Single Crystal Dual Phase Ni-base Superalloy
    Guo Yunqiang Zhang Keshi Geng Xiaoliang Liu Qin
    2007, 36(8):1331-1335.
    [Abstract](1497) [HTML](144) [PDF 0.00 Byte](7)
    Abstract:
    A theory of crystal plasticity including back stress and damage evolutions has been established in this paper. The effects of strain rate on the matrix and precipitate phases of Ni-base superalloy have been analyzed using the theory. The computational result revealed that the both matrix and precipitate phases were seriously affected by strain rate. The nonuniform microcosmic stresses and plastic slips were induced by the microcosmic heterogeneity of single crystal dual phase alloy. The microcosmic plastic slips originate in matrix firstly. The heterogeneity of microcosmic stresses and plastic slips is probably the origin of the damage evolution and the nucleation of micro voids.
    5  Effect of Microelements on the Microstructural Evolution of Al-Ag Alloys during Initial Aging Stage by Kinetic Monte Carlo Model
    Zhou Ming Li Shiehen Zheng Ziqiao Yang Peiyong
    2007, 36(8):1336-1340.
    [Abstract](1385) [HTML](132) [PDF 0.00 Byte](0)
    Abstract:
    采用基于Multi-States Ising Model的Kinetic Monte Carlo算法,模拟研究了添加微量元素对Al-Ag合金时效初期微观结构的演变过程的影响。结果表明:在Al-Ag合金中,In,Sn,Be元素显著地抑制了合金时效初期的Ag原子偏聚,这是这些元素的原子与空位强烈地相互作用的结果。Mg元素对Ag原子的偏聚的抑制次之,添加Mg元素的合金,时效过程中出现了Mg-Ag原子团簇和Ag-Mg-Va团簇,Mg-Ag之间以及Mg-Va之间的共同作用影响了Ag原子的偏聚。Li,Cd原子与Ag原子和空位均无明显作用,因此Li和Cd元素对时效早期Ag原子的团聚影响较小。微量元素是通过与构成析出相的主要溶质元素以及空位的相互作用来实现对原子偏聚过程的影响,进而来影响Al-Ag合金的时效过程的,其中微量元素与空位的相互作用起到关键的作用。锁定单空位和空位团聚进而降低空位可动性是影响Al-Ag合金时效过程的两种重要机制。
    6  Precipitation and Coarsening of Coherent and Ordered Second Phase during Stress Aging by Using Phase-Filed Simulations
    Yang Peiyong Li Shichen Zheng Ziqiao Zhou Ming Wang Donglin
    2007, 36(8):1341-1345.
    [Abstract](1069) [HTML](114) [PDF 0.00 Byte](1)
    Abstract:
    采用双场耦合条件下的宏观相场法,实现了模拟外加应力下无序基体中共格有序第二相的析出和粗化。结果发现,在外加应力下,第二相颗粒将发生定向粗化,形成筏状组织,成筏的方向取决于外加应力的性质、点阵错配的正负以及两相的弹性模量差。沉淀体积分数越大,颗粒合并和反相畴界对沉淀形貌的影响越显著,导致许多颗粒呈现不规则形貌。颗粒的对齐有两种机制,一是链条外颗粒的溶解,一是颗粒的迁移。在粗化过程中,多颗粒体系首先通过前1种机制形成链条,然后通过第2种机制使链条进一步对齐。
    7  Influence of Low Frequency Pulsed Current Annealing on the Giant Magneto Impedance of CoFeSiB Amorphous Ribbon
    Bao Binghao Jiang Feng Sun Chao
    2007, 36(8):1346-1349.
    [Abstract](1120) [HTML](120) [PDF 0.00 Byte](0)
    Abstract:
    研究了经不同低频脉冲电流密度退火的Co66.3Fe3.7Si12B18非晶薄带的巨磁阻抗(GMI)效应。结果表明,在低频脉冲电流下,巨磁阻抗效应的大小与退火电流密度密切相关。非晶带的GMI变化率△Z/Z先随退火电流密度的增加而增强,当电流密度为104A/mm^2时,△Z/Z达到最大值53.8%,此后随电流密度增大,GMI变化率开始减小。对脉冲电流退火影响巨磁阻抗效应的机制作了定性分析。并分析了由脉冲电流退火在材料内感生的横向各向异性场凤对GMI效应的影响,发现HK有利于提高GMI效应的峰值,但同时存在一个临界值,当超过这个值时,GMI效应的峰值减弱。
    8  Numerical Simulation on Temperature Field in Ta/Ta-16MnR Argon-arc Welder Joint
    Li Zhen
    2007, 36(8):1350-1353.
    [Abstract](1262) [HTML](81) [PDF 0.00 Byte](0)
    Abstract:
    利用ANSYS软件对用钽制换热管、Ta/16MnR制管板的管板式换热器中氩弧焊接接头进行了数值模拟,得到了4种尺寸组合焊接接头的温度场数值模拟结果。通过对模拟结果分析,表明钽-钢复合板的钽层厚度是影响焊接质量的主要因素。为了使钽.钢复合板钢层在焊接过程中不出现熔化,钽层厚度要达到2.5mm。这一模拟结果通过文献中的实验结果得到了验证。
    9  The Change of Residual Resistance of Different Purity Beryllium after Heat Treatment
    Zhang Qinglai Bondarev A B Andreev V A Wang Lili Hu Yongxue
    2007, 36(8):1354-1357.
    [Abstract](1191) [HTML](134) [PDF 0.00 Byte](0)
    Abstract:
    运用测量剩余电阻的方法,研究了4.2K温度时不同纯度的铍中剩余相的分解与其溶解动力学。结果表明:时效有效温度取决于金属中含有杂质的数量,随杂质数量的增加而提高;高纯度铍(~99.94%)如微合金一样也具有时效倾向;应用剩余电阻概念研究纯铍内部结构转变是非常有效的方法,它可记录时效过程初始阶段的变化(如400℃铍中扩散分解),这些变化用微观观察或X射线衍射分析很难得到。
    10  Spin Transport Properties of the Thin Film Doped with La0.85Sr0.015MnO3
    Jin Kexin Chen Changle Zhao Shenggui Luo Bingcheng Wang Jianyuan Chen Zhao Gao Guomian Yuan Xiao
    2007, 36(8):1362-1365.
    [Abstract](1120) [HTML](114) [PDF 0.00 Byte](0)
    Abstract:
    采用磁控溅射方法制备了二价碱土元素微量掺杂锰氧化物La0.85Sr0.015MnO3(LSMO)薄膜。电阻-温度关系表明,薄膜在273K时发生铁磁金属-顺磁半导体相变。在磁场和激光作用下,薄膜呈现出不同的响应特性:在整个测试温度区间内,磁场作用使薄膜电阻变小,在243K时,取得最大磁电阻变化率为21%;激光辐照薄膜在不同的相态显示出不同的变化特性,在铁磁金属态导致电阻增大,而在顺磁半导体态则致使电阻减小。从能带理论的角度定性地分析了产生该现象的原因是外场对eg电子的作用不同。
    11  Physical and Electrochemical Properties of Ladoped Lithium Iron Phosphate Electrodes
    Luo Shaohua Tang Zilong Lu Junbiao Zhang Zhongtai
    2007, 36(8):1366-1368.
    [Abstract](1565) [HTML](126) [PDF 0.00 Byte](4)
    Abstract:
    利用固相法合成了镧离子掺杂的Li1-xLaxFePO4正极材料,采用XRD,SEM和充放电性能表征了材料的晶体结构、微观形貌和电化学性能。研究表明,少量La^3+的掺杂未影响到LiFePO4的晶体结构,但显著改变了粉体的微观形貌,降低颗粒粒度至纳米级,改善了可逆容量和循环性能。得到的最佳配比正极材料Li0.99La0.01FePO4,在C/20的充放电速率下,其初始可逆放电容量达到理论容量的73%——123mAh/g,20次充放电循环后表现出良好的容量可循环性,容量没有衰减。引入稀土离子是提高磷酸铁锂新型锂离子正极材料电化学性能的有效方法。
    12  Study on Preparation and Dielectric Properties of Nano-Ag/Epoxy Resin Composite
    Xu Man Feng Junqiang Cao Xiaolong
    2007, 36(8):1369-1372.
    [Abstract](1348) [HTML](148) [PDF 0.00 Byte](20)
    Abstract:
    采用紫外辐照还原的方法制备了纳米银粒子,研究了保护剂的添加、辐照强度和溶液配比等因素对纳米银粒子尺寸的影响。TEM反映出银粒子分散均匀,其粒度约为20nm。将制备出的纳米银与环氧树脂混合固化形成纳米复合电介质,研究了这种复合材料的介电性能:室温下复合材料的体积电阻率和工频击穿场强随着纳米银粒子的加入有所提高,介质损耗略有降低,而介电常数变化不大。结果表明,纳米银粒子能够提高基体聚合物的介电性能。这一现象可用库仑阻塞机制解释。
    13  Fabrication of Cd0.9Zn0.1Te:In by Thermal Annealing Technology under Controlled Indium Vapor
    Liu Hongtao Sang Wenbin Li Wanwan Min Jiahua Li Gang
    2007, 36(8):1373-1376.
    [Abstract](1310) [HTML](144) [PDF 0.00 Byte](11)
    Abstract:
    利用控制In气氛下的热处理工艺成功地制备了CdZnTe:In。不同In压下(Cd,Zn分压保持在平衡分压)的热处理实验结果表明:热处理后样品的电阻率可从6.75×10^5Ω·cm提高到10^8~10^1010Ω·cm;并且随着In压的增加,导电类型逐渐由p型转变为n型。热处理后样品的电阻率变化特征可以由In的扩散和施主缺陷InCd、受主缺陷VCd之间的补偿作用来很好地解释。利用扩散理论建立了CdZnTe:In的电阻率物理模型。利用热处理后样品的电阻率数据,计算了在873,973和1073K时In原子在CZT晶体中的有效扩散系数DIn,分别为3.455×10^-11,2.625×10^-10和5.17×10^-9cm^2/s。将扩散数据经过拟合后得到了DIn的表达式:1.35exp(-1.85eV/kT)cm^2/s(873~1073K)。
    14  Electric Polarized Post Treatment of Plasma Sprayed Hydroxyapatite Coatings in Alkaline Solution
    Huang Yi Yang Bangcheng Feng Jiamin Chen Jiyong Liu Xiaoguang Zhang Xingdong
    2007, 36(8):1377-1381.
    [Abstract](1264) [HTML](119) [PDF 0.00 Byte](9)
    Abstract:
    采用碱液环境中电极化处理法(PAS)和水蒸气处理法(wVT)对等离子喷涂羟基磷灰石涂层进行后处理。采用XRD,FTIR,SEM,接触角测量仪等测试手段对涂层进行表征。结果表明,PAS和WVT都能提高涂层的结晶度和结构完整性,促使涂层中的杂相向羟基磷灰石转化,但PAS比WVT转化得更完全。PAS与WVT两种后处理方法对涂层原有的表面形貌影响都不大。与WVT相比,PAS处理后的涂层亲水性更好、表面能更高,且涂层表面上产生了更多的负电荷。PAS处理后的涂层与基体材料的结合强度略低于WVT,但仍然达到了ISO13779-2:2000标准的相关要求。
    15  Synthesis and Electrochemical Properties of LiMn2O4 Cathode Material
    Li Zhimin Luo Fa Su Xiaolei Zhu Dongmei Zhou Wancheng
    2007, 36(8):1382-1385.
    [Abstract](1440) [HTML](136) [PDF 0.00 Byte](15)
    Abstract:
    根据Li2CO3/MnO2混合粉体的TG-DSC分析结果,采用高温固相反应法,在不同的预保温温度下合成出正极材料LiMn2O4。对其进行XRD,SEM表征和电化学性能测试,确定了在600℃预保温和830℃最终合成的优化工艺。该工艺合成的LiMn2O4粉体具有单一的尖晶石相结构和粒度分布均匀的形貌。组装成电池在常温下循环时,初始放电比容量达122mAh/g,20次循环后容量保持在96%左右。其循环伏安曲线经过20次循环后仍可保持较好的形状。
    16  Monolayer NiAI Composite Reinforced with Mo fibers by Plasma Spray
    Zhang Zhigang Gong Shengkai Xu Huibin
    2007, 36(8):1386-1389.
    [Abstract](1216) [HTML](131) [PDF 0.00 Byte](0)
    Abstract:
    采用等离子喷涂工艺,制备了Mo丝增强的NiAl基单层复合材料。系统地研究了该复合材料的显微组织,Mo丝/NiAl界面的结合特性以及在不同热处理状态下复合材料的界面行为。研究表明:制备态单层复合材料的基体由强烈变形(扁平化)和高速结晶的NiAl熔滴颗粒形成的层状结构构成,颗粒间有较多的分界面,Mo丝/基体的界面结合强度不高,其结合为非冶金结合。800℃,3h退火后,Mo丝/基体界面的结合情况得到改善,复合材料的性能提高。更高温长时处理后,基体元素Ni在Mo丝中形成扩散层,在界面处基体一侧和基体中结晶的熔滴颗粒分界面处的铝的氧化物层明显增厚。
    17  Interfacial Characteristics and Mechanical Properties of W Fiber Reinforced ZrTiCuNiBe Amorphous Matrix Composite
    Chen Chunsheng Li Jinshan Ma Weifeng Kou Hongchao Hu Rui Zhou Lian Fu Hengzhi
    2007, 36(8):1390-1393.
    [Abstract](1386) [HTML](145) [PDF 0.00 Byte](1)
    Abstract:
    The W fiber reinforced Zr41.25Ti13.75Cu12.sNi10Be22.5 amorphous matrix composites with 50 mm in length and 6 mm in diameter have been produced by the melt infiltration casting method. The interface reaction appearance of the composite was analyzed by scanning electron microscopy at the same infiltration time and different infiltration temperatures. The interfacial shear strength of composite is determined by the push-out method. The relations between the macroscopically compressive fracture behaviors with the interracial characteristics and shear strength are discussed in the end. The results indicate that the plastic behaviors and fracture toughness of amorphous alloy were improved obviously, the interracial combination of composites included the two processes of interface diffusion and interface reaction, and the interracial shear strength increased when the interface reaction was pricked up. At the same time, the compressive failure mode of composite changed from the longitudinal split to the single shear failure.
    18  Porous Titanium by Fiber Sintering and Its Biomimetic Ca-P Coating
    Zou Chunming Zhang Erlin Zeng Songyan
    2007, 36(8):1394-1397.
    [Abstract](1275) [HTML](81) [PDF 0.00 Byte](2)
    Abstract:
    采用钛纤维烧结法制备了多孔钛,并应用混合碱-热处理对其表面进行活化处理,然后在过饱和钙磷溶液中进行表面钙磷涂覆。测试了多孔钛的压缩性能,分析了涂层的形貌、元素含量和相组成。结果表明,制备的多孔钛为三维贯通结构,孔隙度在29%~84%,孔隙尺寸为100~800gm。当孔隙度为55%~60%时,压缩屈服强度为150~230MPa,弹性模量为4.0~4.2GPa,与骨组织相近。经表面钙磷涂覆处理的多孔钛在模拟体液中浸泡3天后,内外孔壁均被类骨磷灰石覆盖,表现出良好的诱导骨生长特性。
    19  Effect of Electroless Deposition on the Corrosion Resistance Property for NdFeB Permanent Magnets with Surface Coating of Ni-P Alloy
    Wu Lei Yan Mi Ying Huagen Wu Jinming Luo Wei
    2007, 36(8):1398-1402.
    [Abstract](1353) [HTML](146) [PDF 0.00 Byte](1)
    Abstract:
    The coating technics by electroless deposition with Ni-P alloy on the surface of NdFeB magnets were optimized by orthogonal experiments. The microstructure and morphology of NdFeB magnets with electroless Ni-P deposit from an acidic bath and an alkaline bath were studied and compared. The corrosion rates of Ni-P deposites and substrate were measured in the NaCl solutions of 3.5wt%, the HCl solutions of 10vot% and the NaOH solutions of 20wt%. The corrosion characteristics of Ni-P deposits were evaluated for the two baths by electrochemical potentiodynamic polarization and impedance techniques. The results show that both deposits enhanced the corrosion resistance of substrate. The Ni-P deposit from the acidic bath provides a better protection due to the amorphous structure, and the continuous and compact cystiform microstructure on the surface of coatings.
    20  Electrochemical Properties of SnSb Alloy Anode Materials Synthesized by Carbothermal Reduction
    Yin Chaoli Zhao Hailei Guo Hong Qiu Weihua Jia Xidi
    2007, 36(8):1403-1406.
    [Abstract](1197) [HTML](135) [PDF 0.00 Byte](0)
    Abstract:
    Anode materials of microcrystalline spherical SnSb alloy for lithium-ion batteries were synthesized from tin and antimony oxides by carbothermal reduction. The so-prepared electrode shows a low initial irreversible capacity and good cycling performance. The initial capacity loss and reversible capacities are 160 mAh/g and 650 mAh/g, respectively. The relatively low specific surface area of SnSb particles should be responsible for the low initial irreversible capacity, while the polycrystalline characteristics of SnSb particles is apparently favorable for the improvement of cyclieability of SnSb electrode. The electrochemical reaction process of SnSb alloy electrode was characterized by cyclic voltammetry and AC impedance techniques.
    21  Isothermal Oxidation Behavior of Single-Crystal Ni-Base Superalloy Containing Rhenium in Air
    Liu Chunting Sun Xiaofeng Ma Ji Cong Haiyan Liu Wanfeng
    2007, 36(8):1407-1411.
    [Abstract](1287) [HTML](137) [PDF 0.00 Byte](1)
    Abstract:
    采用X射线衍射(XRD),扫描电镜(SEM)及能谱(EDAX)等手段,研究了含铼单晶高温合金DD32的高温氧化行为。结果表明,氧化初期增重迅速,由NiO的形成和生长控制,符合抛物线规律;随着氧化时间的延长,氧化增重变得十分缓慢,由α-Al2O3的形成和生长控制。在900,1000℃时的氧化膜由3层组成,最外层为(Ni,Co)O层,中间层由复杂化合物以及尖晶石化合物等组成,内层为靠近基体合金的连续的Al2O3层。氧化过程中,分布在中间层的富Re和W相起到“扩散障”的作用,降低基体合金中Al向外的扩散速率,在内层形成均匀连续的Al2O,氧化膜层,进而抑制氧化膜生长,导致氧化速率降低。
    22  Evaluation Methods on Adhesion Property of Metallic Films
    Tang Wu Deng Longjiang Xu Kewei
    2007, 36(8):1412-1415.
    [Abstract](1380) [HTML](141) [PDF 0.00 Byte](0)
    Abstract:
    The adhesion property of Au/NiCr/Ta multi-layered metallic films was investigated by the indentation method, rolling contact fatigue method and scratch method with both friction and acoustic emission modes. The results indicate that the indentation method can not distinguish if the failure happens between the metallic film and substrate and there are no cracks during the indentation process; and the rolling contact fatigue method can not be used to evaluate the adhesion property for metallic films due to the plastic deformation; only the scratch method can eventually be used to distinguish the special scratch behavior for multi-layered metallic films. Additionally, the friction mode can reflect the changes on different metallic film layers, it is more sensitive than the acoustic emission in the same layer. The number of layers and the layer thickness of film and the scratch resistance of metallic films can be reflected by a critical characteristic load at a certain extent.
    23  Morphologies and Microstructures of Ag5Fe Powders Produced by Ultrasonic Arc Gas Atomization
    Yu Long Wan wen Qin Guoyi Chen Nanguang Chen Song Ning Yuantao
    2007, 36(8):1416-1419.
    [Abstract](1430) [HTML](132) [PDF 0.00 Byte](0)
    Abstract:
    利用超音速气雾化的方法制备了液态微溶、固态不互溶的Ag5Fe粉末。利用电弧在放电时的高温使Fe熔解于Ag中,在随后的快速凝固过程中形成含有亚稳合金相的Ag5Fe粉末。扫描电镜观察显示:Ag5Fe粉末的粒度较均匀、细小,呈正态分布,大部分集中在25-55μm;取典型颗粒放大处理后发现:颗粒的富Ag基体中高度弥散分布着粒度在纳米级的Fe相,在富Fe基体中亦有粒度为纳米级的弥散分布的Ag相。计算结果表明:经超音速气雾化之后Ag-Fe合金颗粒有固溶,且粉末颗粒越细小固溶扩展越大。Fe在富银区域中的固溶度亚稳扩展至0-3at%~0.6at%;且在忽略少数粒度较大的粉末颗粒条件下,粉末颗粒越细,亚稳固溶度越大。
    24  Effects of Rare Earth Nd on Microstructure and Mechanical Properties of Laser Rapid Formed TC4 Titanium Alloy
    Zhang Fengying Chen Jing Tan Hua Lin Xin Huang Weidong
    2007, 36(8):1420-1424.
    [Abstract](1498) [HTML](139) [PDF 0.00 Byte](0)
    Abstract:
    针对氢化脱氢钛合金粉末氧含量较高的问题,研究了添加稀土钕对激光快速成形TC4合金组织及性能的影响。结果发现,添加稀土Nd后,激光快速成形TC4合金的宏观晶粒尺寸变化不大;但随稀土添加量的增加,初始β列状晶逐渐转化为全β等轴晶,晶粒内部的魏氏α组织逐渐转变为网篮α,粗化α条不断增多,呈现团束聚集趋势,晶界α集束体积分数也不断增大;随稀土添加量的增加,激光快速成形TC4合金的室温塑性先大幅度提高,然后急剧降低;稀土添加量为0.1%~0.2%(质量分数,下同)时,氧含量为0.26%的氢化脱氢TC4合金粉末激光快速成形件沉积态的抗拉强度达975MPa,延伸率9.5%,满足锻件标准要求。
    25  Influences of Adding Trace RE Elements on the Structure and Properties of Cu-10Ag Alloy in situ Fiber Composites
    Ning Yuantao Zhang Xiaohui Wu Yuejun
    2007, 36(8):1425-1430.
    [Abstract](1233) [HTML](141) [PDF 0.00 Byte](0)
    Abstract:
    制备了Cu-10Ag和Cu-10Ag-RE(RE=Ce,Y,Gd)合金原位纤维复合材料,研究了它们的显微结构与性能。结果表明,微量RE添加剂对合金铸态组织具有变质和细化作用,增大了(Cu+Ag)共晶比例和减少了Ag沉淀比例,并能提高合金的再结晶温度和不连续Ag沉淀温度。随真实应变叩增大,复合材料中Ag纤维平均直径d呈η的负指数函数减小:d=d0·exp(-0.228η),而复合材料的应变强度呈η的指数函数增大:σCu/Ag=σ0(Cu)+[kCu/Agd0^-1/2]exp(η/3)。Cu-10Ag和Cu-10Ag-RE复合材料显示两阶段强化机制:低应变阶段为加工硬化机制,高应变阶段为超细Ag纤维及界面强化机制。微量RE添加剂明显减小凶值,因而明显增高原位纤维复合材料的应变强化速率。
    26  Effects of Rapid Quenching on the Microstructures and Electrochemical Performances of La0.7Mg0.3Ni2.55-xCo0.45Alx (x = 0
    Zhang Yanghuan Ren Huiping Wu Zhongwang Dong Xiaoping Guo Shihai Wang Xinlin
    2007, 36(8):1431-1435.
    [Abstract](1393) [HTML](128) [PDF 0.00 Byte](12)
    Abstract:
    用铸造及快淬工艺制备了La-Mg-Ni系(PuNi3型)电极合金La0.7Mg0.3Ni2.55-xCo0.45Alx(x=0,0.1,0.2,0.3,0.4),研究了快淬工艺对合金微观结构及电化学性能的影响。XRD分析结果表明,铸态及快淬态合金具有多相结构,包括(La,Mg)Ni3相和LaNi5相和一定量的LaNi2相,快淬处理对合金的相组成没有影响,但使相的相对含量产生变化。TEM及SEM分析结果表明,快淬处理显著改善合金的成分均匀性,使晶粒细化。Al替代Ni不利于非晶相的形成,但使快淬态合金的晶粒显著细化。电化学测试结果表明,快淬处理显著提高合金的循环稳定性,但不同程度地降低合金的放电容量和活化性能,快淬对放电电压特性的影响是复杂的。
    27  Fabrication of Er3+:Y2O3 Nanocrystalline Powder of Upconversion Luminescence by Co-precipitation
    Luo Junming Li Yongxiu Deng Liping YuanYongrui
    2007, 36(8):1436-1439.
    [Abstract](1425) [HTML](125) [PDF 0.00 Byte](1)
    Abstract:
    以Y2O3为基质材料,掺杂不同含量的Er^3+,采用共沉淀法制备出性能良好的Er^3+:Y2O3上转换发光纳米粉。对不同温度下煅烧后的粉体进行了X射线衍射、能谱测试、透射电镜和比表面积分析。结果表明:Er^3+完全固溶于Y2O3的立方晶格中,Er^3+:Y2O3粉体粒度均匀,近似球形,且随着煅烧温度的升高,其颗粒逐渐变大;1000℃煅烧2h的粉末尺寸为40~60nm。
    28  Effect of Amorphous Carbon Doping on Microstructure and Superconducting Properties of MgB2 Bulk
    Wang Qingyang Yah Guo Liu Guoqing Li Jinshan Zhang Pingxing Lu Yafeng Yang Ye Pu Minghua Zhao Yong
    2007, 36(8):1440-1443.
    [Abstract](1199) [HTML](125) [PDF 0.00 Byte](4)
    Abstract:
    以无定形碳粉末作为掺杂物质,通过固相烧结的方法,在750℃,高纯氩气保护下,热处理2h制备了MgB2-xCx(x=0,0.05,0.10,0.20,0.30)超导块材。用X射线衍射(XRD)仪,扫描电子显微镜(SEM)和物性测试仪(PPMS)对样品的微观结构和超导电性进行了系统分析。结果显示,在750℃热处理条件下,有部分碳进入MgB2的晶格中,其余碳处于MgB2的晶界处。少量碳掺杂可以有效细化MgB2晶粒,并改善MgB2的超导电性。MgB19C0.1块材的临界电流密度(Jc)在20K,3T条件下达到8×10^4A/cm^2,表明无定形碳掺杂可有效提高MgB2的磁通钉扎。
    29  Evaluation on Microtructures and Properties of Laser Cladding Layer for WFLC-11 Co-based Alloy
    Pan Lin Gao Wanzhen Tao Xiqi Xia Chunhuai
    2007, 36(8):1444-1446.
    [Abstract](1480) [HTML](131) [PDF 0.00 Byte](15)
    Abstract:
    对自主开发的WFLC-11激光熔覆专用钴基合金粉末激光熔覆层与Stellite-6合金等离子喷焊层的组织与性能进行了比较研究。结果表明,激光熔覆层组织细小、均匀,致密性好,高温硬度更高,其显微硬度、耐腐蚀性能、抗擦伤性能优于Sellite-6合金等离子喷焊层。
    30  Influences of Electrolyte Parameters on the Structure and Properties of Micro-Arc Oxidation Coatings of Zicralloy
    Zhang Dailan Bai Xind Li Hongyi Chen Jianxin Wu Zhiming Zhu Guosheng
    2007, 36(8):1447-1451.
    [Abstract](1312) [HTML](128) [PDF 0.00 Byte](1)
    Abstract:
    研究了不同电解液参数对于Zr合金微弧氧化膜结构和性能的影响。实验证明,在不同浓度的NaOH溶液中,微弧氧化反应的击穿电压与阴离子浓度成反比,并且溶液的浓度不能过高或者过低。采用NaOH,Na2SiO3和Na3PO43种溶液作为电解液产生的微弧氧化膜,在结构和形貌上有很大的区别。电解液中的阴离子会参与微弧氧化反应。氧化膜中的Si元素有利于稳定ZrO2的高温相,并使氧化膜结构平整、减少孔洞和裂纹,提高合金耐腐蚀性,而P元素却有着相反的作用。
    31  Influence of Preparing Conditions on the Particle Size of Indium Tin Oxide (ITO) Powders
    Chen Lin Wu Bolin
    2007, 36(8):1452-1456.
    [Abstract](1651) [HTML](131) [PDF 0.00 Byte](11)
    Abstract:
    以纯In,SnCl4·5H2O和盐酸为原料,采用络盐法制备了纳米晶铟锡氧化物(ITO)粉末。通过对铟和锡的络合盐——(NH4)2InCl5·H2O和(NH4)2SnCl6的制备研究,充分证实了反应初始溶液中络离子的存在;通过调节氯离子与铟离子的总浓度比(TCl/TIn)研究了络离子对ITO粉末粒度的影响,还系统地研究了沉淀剂的浓度、终点pH值、前驱体洗涤次数和煅烧温度对ITO粉末粒度的影响:通过XRD和激光粒度仪对所制粉体进行了表征。结果表明:当TCl/TIn=5,沉淀剂为20%的NH4HCO3溶液,终点pH值为6.0~7.0,前驱体的洗涤次数为6次,煅烧温度为700~800℃时所得ITO粉末粒度最佳。
    32  Fabrication of Hard/Soft Nanocomposite Magnetic Particles by Sonochemistry
    Li Baowei Li Yongli Zhang Jiuxing
    2007, 36(8):1457-1460.
    [Abstract](1225) [HTML](131) [PDF 0.00 Byte](0)
    Abstract:
    Sm-Fe-N/Fe and Nd-Fe-B/Fe nanocomposite magnetic powders were successfully prepared by the use of sonochemistry to decompose the carbonyl iron compounds in decane solvents containing Sm-Fe-N and Nd-Fe-B powders at low temperature and in an inert atmosphere, respectively. The TEM observations and the corresponding EDS analysis show that the small nano-iron by sonochemical process are pure with a particle size of about 5 rim. The SEM observations indicate that the Sm-Fe-N and Nd-Fe-B powders are well coated by nano-sized Fe. The content coating Fe can be easily adjusted by controlling the carbonyl iron and the related sonochemical process. In addition, the preparation conditions and mechanism of coating process were discussed.
    33  Spark Plasma Sintering of ODS Cobalt Base Alloy Powder by Mechanical Alloying
    Tang Chunfeng Qu Xuanhui Zhou Ting Duan Baihua He Xinbo Qin Mingli
    2007, 36(8):1461-1464.
    [Abstract](1491) [HTML](139) [PDF 0.00 Byte](0)
    Abstract:
    采用机械合金化(MA)和放电等离子烧结(SPS)技术制备了Y2O3弥散强化Co基合金,研究了高能球磨过程中粉末形貌和微观结构的变化规律以及机械合金化粉末的放电等离子烧结行为。结果表明:在球磨的初始阶段(≤8h),粉末粒度和晶粒尺寸显著减小,晶格畸变增大;球磨8h以后,粉末粒度、晶粒尺寸和晶格畸变的变化渐缓;但进一步延长球磨时间,使Y2O3弥散粒子的分布更加均匀。采用放电等离子烧结技术,在1100℃,10min条件下便可制备出相对密度〉99%的合金试样,所得合金平均晶粒小于5μm,经过均匀化热处理后,合金的室温抗压强度和压缩延伸率分别达到1982MPa和27%,优于铸造钻基合金。
    34  Influence of PEG Dispersant on the Stability of ITO Precursor Slurry
    Piao Shengjie Liu Jiaxiang Zeng Shengnan
    2007, 36(8):1465-1468.
    [Abstract](1254) [HTML](136) [PDF 0.00 Byte](2)
    Abstract:
    以金属铟和结晶四氯化锡为原料,加入各种添加剂制备了稳定的ITO前驱物浆料。利用Zeta电位、扫描电镜、沉降试验研究了分散剂PEG对浆料稳定性能的影响。结果表明,分散剂PEG与ITO前驱物氢氧化物胶粒表面建立了较强的氢键,通过空间位阻稳定作用提高了浆料的稳定性;PEG的加入可使浆料中固体颗粒分散均匀,颗粒粒度主要分布在50~100nm之间;沉降试验和粘度的测定表明,浆料pH值在8.0,分散剂PEG用量在1.0%~2.0%(质量分数,下同),粘度在2.1-2.6mPa·s时,在沉降120h后的浆料中,固体颗粒沉降体积百分比在10%以内,能够保证浆料的相对稳定。
    35  Microstructure and Magnetic Properties of Amorphous FeTsSi9B13 Alloy in Low Frequency Pulse Magnetic Field
    Zhang Yanhui Chao Yuesheng
    2007, 36(8):1469-1472.
    [Abstract](1377) [HTML](139) [PDF 0.00 Byte](5)
    Abstract:
    研究了低频脉冲磁场处理对非晶合金Fe78Si9B13微观结构及磁性的影响。用非接触红外测温仪对试样的温升进行测量,用穆斯堡尔谱仪、透射电镜等仪器对样品的组织结构、晶化行为进行分析,利用交变梯度磁强计AGM对样品的磁性进行测试。结果表明,低频脉冲磁场处理(脉冲频率f=10-40Hz,磁场强度H=(100~400)×79.6A/m,处理时间t=-180-1200s)可在温升△T≤7℃的情况下,促进非晶合金Fe78Si9B13发生单相晶化,晶化相为α-Fe(Si),晶粒尺寸为2~10nm,析出量为3%~7%。样品在经过f=40Hz,H=300×79.6A/m,t=300s处理后,获得较好磁性能:Bs=1.74T,H0=0.13×79.6A·m^-1。
    36  Effect of Ce-La Mixed Rare Earth Content and Environment Conditions on the Creep Rupture Life of SnAgCu Solder Joints
    Zhang Keke Wang Yaoli Fan Yanli Zhu Yaomin Zhang Xin Yan Yanfu
    2007, 36(8):1473-1476.
    [Abstract](1182) [HTML](136) [PDF 0.00 Byte](0)
    Abstract:
    采用搭接面积为1mm^2的微型接头,研究了Ce-La混合稀土(RE)含量和环境条件对Sn2.5Ag0.7CuxRE钎料钎焊接头蠕变断裂寿命的影响。结果表明:添加微量RE可改变钎焊接头界面层金属间化合物的几何尺寸及形态,从而影响SnAgCuRE钎料合金钎焊焊点的蠕变断裂寿命。当RE添加量为0.1%时(质量分数,下同),焊点界面金属间化合物尺寸小且均匀,蠕变断裂寿命最长,为SnAgCu焊点蠕变断裂寿命的8.4倍,其值明显高于商用钎料Sn3.8Ag0.7Cu焊点的蠕变断裂寿命。在相同条件下,焊点的服役温度升高、应力增加,将导致焊点的蠕变断裂寿命下降。
    37  Preparation and Properties of Spherical Spinel LiMn2O4 Cathode by Electrolysis at Low Temperatures
    Zhou Yuan Yue Hongfei Ran Guangfen
    2007, 36(8):1477-1479.
    [Abstract](1184) [HTML](137) [PDF 0.00 Byte](0)
    Abstract:
    采用MnSO4-H2SO4混合溶液作电解液,高纯铅板作电极,控制电解池温度为0~10℃,低温电解制取球形MnO2微粒;将其用一定浓度硝酸锂溶液浸渍,经过520℃低温合成、760℃高温结晶获得球径较为均一的球形尖晶石锰酸锂锂离子电池正极材料。通过XRD和SEM对其进行了相结构表征和表面形貌观察。组装试验电池,测得材料初始容量约为105mAh·g^-1,6次循环放电后循环过程趋于稳定,第30次循环充电容量保持在98.1mAh·g^-1,放电容量保持在95.0mAh·g^-1,表现出良好的充放电循环性能。
    38  Electrodeposition of Rare Earth Magnetic Funcition Alloy Nanowires in Nonaqueous System
    Su Yikun Tang Jiaoning Yao Ying Gong Xiaozhong Fan Fan Li Junqin
    2007, 36(8):1480-1482.
    [Abstract](1450) [HTML](160) [PDF 0.00 Byte](7)
    Abstract:
    利用多孔阳极氧化铝模板,在尿素-NaBr-KBr-酰胺体系中电沉积稀土-铁系金属(La-Co)合金纳米线。用扫描电子显微镜(SEM)观察(La-Co)合金纳米线的表面形貌,用磁振动样品磁强计(VSM)研究了LaCo合金的磁性。结果表明,纳米线直径较为均匀,且每条纳米线的尺寸为70~80nm,与AAO模板的纳米孔径大小相符合:X射线衍射(XRD)分析表明,La-Co合金为LaCo5晶体;在室温下呈现顺磁性的La,当与Co形成合金后,饱和磁矩接近于磁性金属Co。
    39  Combustion Synthesis of Fe-Ti-C System by Electric Field Inducement:Effect of Electric Current on the Synthesis Products
    Wang Hongliang Yang Yi Feng Keqin Lin Huimin Wang Wenjuan
    2007, 36(8):1483-1486.
    [Abstract](1218) [HTML](134) [PDF 0.00 Byte](0)
    Abstract:
    采用Gleeble-1500D热模拟试验机,利用电场诱导Fe—Ti—C体系发生燃烧合成反应,并研究了外加电流对合成产物的影响。对产物进行了X射线衍射(XRD)和扫描电镜(SEM)等分析。结果表明:产物中均存在TiC相,而少量的Fe2Ti相仅存在于特定的阶段:随着外加电流的增加,颗粒的平均尺寸也发生不同程度的减小。外加电场能够促进反应物粒子的固相扩散和形核长大,并最终影响合成产物的物相组成和颗粒尺寸。
    40  Age-Hardening Mechanism of Pd-Ag-Sn-In-Zn Alloy
    Wu Haijun Zhang Guoqing Song Hongqing Wan Jigao Zhang Ruihua Huang Bingxing
    2007, 36(8):1487-1489.
    [Abstract](1223) [HTML](130) [PDF 0.00 Byte](0)
    Abstract:
    Age-hardening behaviour and the related microstructural changes were studied to elucidate the hardening mechanism of Pd-Ag-Sn-In-Zn alloy by means of hardness test, XRD, SEM. It is shown that the increase of hardness during the early stage of age-hardening is related to the formation of intermediate precipitate phase at the grain boundary. The single phase solid solution matrix and the lameUar-like precipitate phase similar to pearlite were observed at the grain boundary by SEM. The hardness is decreasing with the coarsening of the stable second phase.
    41  Research Progress in Silicon Based Anode Materials for Lithium-Ion Batteries
    Zhao Jishi He Xiangming Wan Chunrong Jiang Changyin
    2007, 36(8):1490-1494.
    [Abstract](1565) [HTML](144) [PDF 0.00 Byte](4)
    Abstract:
    New anode materials with high specific capacity for lithium-ion batteries have been widely studied in recent years. Silicon and / silicon based compounds have been studied as the anode materials due to their high theoretic capacity. However, the cyclic performance of the silicon based materials must needs to be improved. In this paper, the research progresses in the silicon based anode materials for Li-ion batteries are reviewed; the problems and prospects for these materials are also discussed.
    42  Shape-Controlled Synthesis and Applications of Silver Nano-Particles
    Zhang Taiwei Zhang Lu Yang Shengchun Yang Zhimao Ding Bingjun
    2007, 36(8):1495-1499.
    [Abstract](1408) [HTML](145) [PDF 0.00 Byte](1)
    Abstract:
    纳米金属颗粒由于小尺寸效应、表面效应、量子尺寸效应显示出与块体材料不同的热、光、电、磁、催化等性能。纳米金属材料的性能不仅与粒子尺寸有关,而且还受到粒子形貌的影响。近年来,金属纳米粒子的形状控制合成受到了特别的关注。本文着重评述近年来金属纳米粒子形状控制合成的方法并以银为例介绍了其形状控制合成的最新研究进展。
    43  The Optimization Research Developments of Grain Boundary Character Distribution (GBCD) of Polycrystalline Metal Materials
    Fang Xiaoying Wang Weiguo Zhou Bangxin
    2007, 36(8):1500-1504.
    [Abstract](1287) [HTML](152) [PDF 0.00 Byte](5)
    Abstract:
    总结了基于退火孪晶的金属材料晶界特征分布(GBCD)优化研究进展,并重点讨论了退火孪晶诱发GBCD优化的“∑3再激发”模型、“高∑-CSL晶界分解反应”模型和“非共格∑3晶界迁移与反应”模型。指出“非共格∑3晶界的迁移与反应”应是基于退火孪晶的中低层错能金属材料GBCD优化的微观机制;进一步研究非共格∑3晶界的成因及其在GBCD优化过程中的行为是十分必要的。

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