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Volume 33,Issue 12,2004 Table of Contents

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  • 1  Research on the Elastic Modulus of the Carbon Nanotubes
    Zhang Zhenhua Peng Jingcui Chen Xiaohua
    2004, 33(12):1233-1237.
    [Abstract](1180) [HTML](144) [PDF 0.00 Byte](0)
    Abstract:
    本文从精巧的实验测量和独到的理论计算两方面对碳纳米管杨氏弹性模量的研究方法、实验原理、基本理论、主要发现及意义等进行讨论。实验测量方法主要包括CNTs自由端振动法、AFM探针偏折或拉伸CNTs等,理论计算方法主要涉及到连续体模型,分子动力学模拟或两者相结合的混合方法。
    2  Directional Solidification in YBCO Superconductors
    Li Jinshan Zhu Dan Geng Xingguo Hu Rui Chen Zhongwei Fu Hengzhi
    2004, 33(12):1238-1242.
    [Abstract](1227) [HTML](150) [PDF 0.00 Byte](8)
    Abstract:
    Some basic problems in preparing YBCO superconductor by directional solidification, including the peritectic reaction , the interface stability and its control , the orientation of solidification, and crystal orientation control , were discussed. Many problems have been revealed and must be overcome in the future, in order to get an optimum structure.
    3  The Present Status of Study of Ti Alloy for Dentistry
    Zhang Xinping Yu Sirong He Zhenming
    2004, 33(12):1243-1247.
    [Abstract](1604) [HTML](173) [PDF 0.00 Byte](0)
    Abstract:
    The purpose of this article is to review the development and applications of titanium and its alloys on dental material, including the elastic modulus, the tensile strength, the yield strength and the extensibility of dental Ti alloys, the effects of halogen ions on the corrosion of dental Ti alloy, the galvanic couple corrosion of Ti alloy combined with others type metal and the microbiological corrosion of dental Ti alloy in oral environment, the surface characteristic and the effect of roughness on the wettability, the recommended alloy elements and using d-electron alloy design theory when designing new dental Ti alloys. The existing problems and the research tendency of dental Ti and Ti alloy were discussed.
    4  Progress in Thermal Residual Stresses of Continuous Fiber Reinforced Titanium Matrix Composites
    Ma Zhijun Yang Yanqing Zhu Yan Chen Yan
    2004, 33(12):1248-1251.
    [Abstract](1274) [HTML](140) [PDF 0.00 Byte](0)
    Abstract:
    This paper reviews the analytical measurements of thermal residual stresses (TRS) for continuos fiber reinforced titanium matrix composites, such as X-ray and neutron diffraction, layer removal method, slitting method, selectively matrix corrosive method and so on, and the effect of TRS on mechanical properties of the composite, and discusses the different kinds of methods for reducing the thermal residual stresses. Finally, present investigative limitation and areas for further research are outlined.
    5  Preparation and Microstructure of Particulate Reinforced Titanium Alloy Matrix Composites
    Li Jungang Jin Yunxue Li Qingfen
    2004, 33(12):1252-1256.
    [Abstract](1322) [HTML](154) [PDF 0.00 Byte](14)
    Abstract:
    The preparation of in-situ particulate reinforced titanium alloy matrix composites in recent years were reviewed, which includes powder metallurgy, melting-casting, XDTM (Exothermic Dispersion), SHS(Self-propagating High-temperature Synthesis), SHS-melting- casting, CR(Contact Reaction ), MA(Mechnical Alloying), laser-melting cladding et al. Microstructures of carbide and boride reinforced respectively titanium alloy matrix composites by different fabrication methods were reviewed. The carbide reinforcements include TiC, Ti2AlC, Ti3AlC et al. The boride reinforcements include TiB2 and TiB. The morphology of reinforced phase were analyzed respectively. Future prospect for these titanium alloy matrix composites was discussed.
    6  Phase Separation of Zr-Ti-Cu-Ni-Be Bulk Amorphous Alloy during Isothermal Annealing
    Shen Jun Gao Yulai Sun Jianfei Chen Demin Wang Gang Xing Dawei Zhou Bide
    2004, 33(12):1257-1260.
    [Abstract](1627) [HTML](142) [PDF 0.00 Byte](10)
    Abstract:
    Employing differential scanning calorimetry (DSC) and transmission electron microscopy (TEM), the isothermal crystallization process and precipitated phases of Zr41.2Ti13.8Cu12.5Ni10Be22.5 (at%) bulk amorphous alloy were investigated. It is found that the bulk amorphous alloy exhibited a multi-stage crystallization behavior when being isothermal annealed. The precipitated phases are different at various crystallization stages. The experiment results show that the main precipitation phase is body-centered tetragonal (b.c.t) Zr2Cu at the first crystallization stage but primitive hexagonal ZrBe2 at the second stage, confirming that the Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk amorphous alloy possesses a phase separation tendency during the isothermal annealing processes. The X-ray diffraction (XRD) result validated that the main precipitation phases were Zr2Cu and ZrBe2 when the bulk amorphous alloy was fully crystallized.
    7  Density of Liquid Binary Ni-W Alloys Measured by Modified Sessile Drop Method
    Fang Liang Xiao Feng Tao Zainan
    2004, 33(12):1261-1265.
    [Abstract](1459) [HTML](143) [PDF 0.00 Byte](0)
    Abstract:
    为了给研究合金在凝固过程中发生收缩、迁移现象和偏析提供科学依据,我们用改良静滴法对钨浓度为0到15%的液态Ni-W二元合金的密度进行了测量.结果表明Ni-W二元合金的液态密度随温度的增加而减少,但随合金中钨浓度的增加而增加;液态Ni-W二元合金的摩尔体积随温度和合金中钨浓度的增加而增加.金属钨在Ni-W二元合金中的偏摩尔体积约为(10.80-1.35×10-3T)×10-6m3·mol-1.
    8  Study on Oxidation Kinetics of Ignition-Proof Magnesium Alloys with Rare Earth Addition
    Fan Jianfeng Yang Gencang Cheng Suling Xie Hui Hao Weixin Wang Mei Zhou Yaohe
    2004, 33(12):1266-1269.
    [Abstract](1539) [HTML](142) [PDF 0.00 Byte](14)
    Abstract:
    Ignition-proof magnesium alloy was acquired by the addition of rare earth elements(Y,Ce). The alloy at 1 173 K exposure to air for 0.5 h can not be ignited. XRD and SEM analysis revealed that the protective oxide film with two layers structure was formed on the surface of Mg-Y-Ce alloy. Thermogravimetric measurements indicated that the oxidation dynamics curve measured at 673 K and 773 K follows the parabolic-line law and the curve investigated at 873 K follows complicate quartic law.
    9  Research on Sintered Behavior and Structure Performance of Ti-NdAl Alloy for Powder Metallurgy
    Tang Huiping Liu Yong Huang Boyun Liu Haiyan Huang Yuanping
    2004, 33(12):1270-1273.
    [Abstract](1384) [HTML](149) [PDF 0.00 Byte](10)
    Abstract:
    用元素混合法研究了粉末冶金Ti-NdAl合金的烧结致密化行为及力学性能。结果表明,粉末冶金Ti-NdAl合金中由于稀土元素钕的存在,其烧结过程中出现液相,同时稀土钕对钛粉末表面氧有净化作用,二者促进了粉末钛的致密化过程。烧结密度可以达到99%以上。显微组织分析表明,粉末烧结Ti-NdAl合金是单相。相,随着钕含量的增加,晶粒细化。该合金烧结态试样中存在生长孪晶。对粉末冶金Ti-NdAl合金的室温力学性能检测结果表明,随着稀土钕含量的增加,Ti-NdAl合金室温拉伸强度不变,而塑性得到大幅度改善。Ti-1.6%Nd0.4%Al合金的强度为728MPa,延伸率为15%。
    10  Response of Osteoblast to CVI C/C and HA Coating on CVI C/C in Vitro
    Ma Chufan Xiong Xinbo Li Hejun Huang Jianfeng Lu Jinhua Hu Zhibiao
    2004, 33(12):1274-1277.
    [Abstract](1292) [HTML](144) [PDF 0.00 Byte](9)
    Abstract:
    采用声电化学工艺在CVI C/C复合材料表面制备了HA涂层,分别用SEM,XPS,EDAX和XRD表征了CVI C/C和HA的表面形貌、组成和结构,同时对比了成骨细胞在其表面的粘附、增殖和碱性磷酸酶活性的表达。制备的HA涂层为球状形貌,由纳米片状晶体构成。细胞培养初期,粘附于HA涂层表面的细胞数与CVI C/C表面的细胞数无显著差别,成骨细胞在CVI C/C表面易铺展在孔的边缘,8h后粘附于HA表面的成骨细胞数显著多于CVI C/C表面。HA涂层提高了细胞的增殖能力,成骨细胞碱性磷酸酶在HA涂层表面的表达也优于CVI C/C材料。结果表明,声电化学制备的HA涂层提高了CVI C/C材料的生物活性和生物相容性,可以加速成骨细胞的粘附、增殖、分化和成熟。成骨细胞在材料表面的粘附机制是由多因素综合作用的,材料的表面形貌和生物活性在细胞粘附过程的早期发挥着重要作用。
    11  Synthesis and Analysis of Antibacterial Functional Film
    Deng Pingye Bai Xinde Ye Bin Liu Xiaomin Feng Qingling
    2004, 33(12):1278-1282.
    [Abstract](1336) [HTML](154) [PDF 0.00 Byte](0)
    Abstract:
    A method of synthesizing novel anodic alumina films with antibacterial property is presented. The process includes preparing a film by anodic oxidation of aluminum and subsequently introducing silver to the films. The antibacterial effect of such a film was estimated by in vitro tests. Escherichia Coli and Staphylococcus aureus were chosen as bacteria to test the antibacterial capacity of such films. It is found that the antibacterial effect was achieved by releasing of silver ions and the effect could be lasting for more than 24 months in atmospheric condition. Scanning electron microscopy was employed to survey antibacterial film. The chemical state of silver in the films was analyzed by X-ray photoelectron spectrum, and Auger electron spectrum was performed to determine the concentration of silver atoms in various films. Ions releasing experimental was carried out in water and the mixture of water and dilute nitric acid, the amount of silver ions releasing from the film was measured, and the total amount of silver in the films was more than 0.13 mg. This antibacterial film can be widely applied and its antibacterial effect maintained for a long time.
    12  Preparation of Hydrogen Storage Alloy La0.67Mg0.33Ni2.5Co0.5 and Its Electrochemical Properties
    Wang Dahui Luo Yongchun Yan Ruxu Xing Changce Kang Long
    2004, 33(12):1283-1286.
    [Abstract](1544) [HTML](148) [PDF 0.00 Byte](10)
    Abstract:
    The La0.67Mg0.33Ni2.5Co0.5 hydrogen storage alloy with PuNi3-type was prepared using induction melting followed by heating treatment. In order to compensate Mg loss during alloy melting, the different mass percent Mg was supplemented into the melt. The microstructure and electrochemical properties of the alloys were investigated by using XRD and electrochemical method. The results show that the ingot is composed of main phase with PuNi3 type structure and a little second phase with CaCu5 structure. After heat treatment at 1 223 K for 10 h, the amount of the second phase in the annealed alloy is remarkably decreased and a more homogenous and purified PuNi3 type microstructure is obtained in the case of 10% Mg supplement. The electrochemical analyses show that the electrochemical properties of the alloy, such as activation, capacity, cycling stability and discharge ability at different current density, are well improved by supplementing proper Mg and annealing heat treatment. In comparison with AB5 type and AB2 with laves phase hydrogen storage alloys, the La0.67Mg0.33Ni2.5Co0.5 alloy has high capacity and quite good kinetics of electrochemical reaction.
    13  Study on Electromagnetic Shaping and Directional Solidificatoin for Supperalloy Plate-Form Parts
    Lu Baiping Shen Jun Yu Jianwei Liu Lin Fu Hengzhi
    2004, 33(12):1295-1298.
    [Abstract](1165) [HTML](142) [PDF 0.00 Byte](9)
    Abstract:
    The process, inductor structure, and screen of electromagnetic shaping for plate-form with big width-to-thick ratio is studied. The results indicate that the logical structure of inductor can melt plate-form equably along its perimeter in cross section and confide melt to a certainty. Screen can regulate the magnetic flux density distribution to assure melt in ideal state in shaping inductor. There is a rational drawing velocity to match electrical power at the constant conditions. At last, the superalloy plate-form parts with qualified surface and directional solidification structure are obtained.
    14  Quantitative Evaluation of the Adhesive Strength of Diamond Thin Films by Bulge/Blister Test
    Jian Xiaogang Chen Ming Sun Fanghong Zhang Zhiming Shen Heshen
    2004, 33(12):1299-1303.
    [Abstract](1218) [HTML](135) [PDF 0.00 Byte](11)
    Abstract:
    On base of the principle of bulge/blister, special experimental equipment adapted for precise quantitative evaluation of the adhesive strength of diamond thin films was designed and fabricated, and free-standing windows sample of diamond thin film was fabricated by a new method developed on the base of conventional process technology of Si plane, which can ensure full diamond coatings from damage during the process of etching the free-standing windows. The average adhesion strength of diamond thin films calculated from the tests of the square membranes is 4.287 26 J/m2, which was coincident with simulation outcomes, so it was approved that the initial calculating model was validity. According to these test results, the adhesive strength could be obtained precisely and quantitatively by bulge/blister test, which can provide a basis for the optimization of diamond thin films fabrication technics and a criterion for the quality evaluation of diamond thin films, and the results will be beneficial to wide application of diamond thin films in the tool-engineering field.
    15  Experimental Study on Residual Stress Distribution of Laser Rapid Forming Process
    Yang Jian Chen Jing Yang Haiou Lin Xin Huang Weidong
    2004, 33(12):1304-1307.
    [Abstract](1381) [HTML](128) [PDF 0.00 Byte](11)
    Abstract:
    The test specimens which consist of Ni20 alloy powder as a cladding metal on the stainless steel 1Cr18Ni9Ti substrate was prepared by using laser rapid forming process and the residual stress distribution in the specimens was analyzed through the hole-drilling method. The results show that the residual stress level in the specimens is lower and belongs to low residual stress domain. The cladding metal near the substrate bore with a compressive stress parallel to the direction of laser scanning. With the increase of the number of cladding layer the value of the compressive stress minimizes gradually and transforms to tensile stress with the value increasing. Conversely, the residual stress perpendicular to the direction of laser scanning is smaller.
    16  Effect of Substitution of Chromium for Manganese on Structure and Electrochemical Discharge Characteristics of Ti0.8Zr0.2V1.6Mn0.8Ni0.6 Multi-Phase Hydrogen Storage Electrode Alloys
    Wang Guoyuan Xu Yanhui Pan Hongge Chen Changpin
    2004, 33(12):1308-1311.
    [Abstract](1511) [HTML](135) [PDF 0.00 Byte](0)
    Abstract:
    采用电化学测试技术、X射线衍射等技术研究了Ti0.8Zr0.2V1.6Mn0.8Ni0.6(0≤x≤0.64)贮氢电极合金的结构和电化学放电特性。研究表明:合金由C14 Laves相和BCC相构成;铬替代锰的量越多,枝晶组织越粗大。X射线衍射发现替代影响合金的晶格参数。合金的最大电化学放电容量为545mAh/g,电化学活化容易,但循环性能比较差。随着替代量增大,由于铬抑制了钛、锆和钒元素的表面迁移和氧化使合金的循环性能退化明显减轻,但同时因为替代使晶胞过大导致最大电化学放电容量有所降低。
    17  Synthesized by Ball Milling Al-Pb-Si-Sn-Cu Nanocrystalline Powder
    Ran Guang Zhou Jing`en Li Pengliang Xi Shengqi Zhang Zhongwu
    2004, 33(12):1312-1316.
    [Abstract](1667) [HTML](147) [PDF 0.00 Byte](9)
    Abstract:
    The nanocrystalline powder of Al-15%Pb-4%Si-1%Sn-1.5%Cu (mass%) were prepared by mechanical alloying. Systematical investigations were carried out on the structural change, grain size, lattice constant, morphology of the powder and the chemical composition of the Al-15%Pb-4%Si-1%Sn-1.5%Cu high energy ball milled powder using X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy(SEM). The experimental results showed that the nanocrystalline powders were synthesized and the homogenous nanophases was achieved by mechanical alloying. The effect of ball milling was more evident to lead than to aluminum. The grain size of Pb was 40 nm after milling for 40 h, and the grain size of aluminum was 65 nm after milling for 60 h. The solid solutions of Al(Cu, Si) and Pb(Sn), and supersaturated solid solution of Pb(Al) were observed by MA. Otherwise, brittle element powder of silicon was more difficulty alloying in the mechanical alloying process.
    18  Preparation and Mechanical Properties of Zr-Based Containing Co Bulk Metallic Glass
    Wu Xiaofeng Zhang Haifeng Qiu Keqiang Yang Hongcai Hu Zhuangqi
    2004, 33(12):1317-1320.
    [Abstract](1220) [HTML](142) [PDF 0.00 Byte](10)
    Abstract:
    采用水淬法制备了Zr—Ti—Cu—Ni—Be—Co块状非晶合金(BMGs)。使用XRD进行相分析,采用热分析仪进行玻璃转变温度、晶化温度和热稳定性等的测定,用SEM观察试样压缩后的外表面和断口形貌。研究了Co对Zr—Ti—Cu—Ni—Be合金非晶形成能力(GFA)、热稳定性及力学性能的影响。结果表明:含Co的所有Zr—Ti—Cu—Ni—Be BMGs都有1个明显的玻璃转变点和宽的过冷液相区(△T)。Zr38Ti17Cu10.5Co12Be22.5合金具有和Zr41Ti14Cu12.5Ni10Be22.5合金相当的△T;Co的添加明显提高Zr—Ti—Cu—Ni—Be BMGs的力学性能,含Co量大于10at%的Zr—Ti—Cu—Ni—Be BMGs的压缩断裂强度(σf)超过2000MPa,Zr38Ti17Co22.5Be22.5合金的σf达到2230MPa,比Zr41Ti14Cu12.5Ni10Be22.5合金的σf提高23%。
    19  The Effect of Rapid Quenching on the Cycle Lives of H2-Storage Electrode Alloys with AB2 Laves Phase
    Zhang Yanghuan Li Ping Wang Xinlin Qi Yan Lin Yufang Wang Guoqing
    2004, 33(12):1321-1324.
    [Abstract](1163) [HTML](151) [PDF 0.00 Byte](0)
    Abstract:
    The effects of rapid quenching on the cycle stability of the H2-storage electrode alloy with AB2 Laves phase were investigated comprehensively. The phase structures and morphologies of as-cast and quenched alloys were determined and observed by XRD and SEM. The results showed that the influences of rapid quenching on the cycle stability of the H2-storage electrode alloy with AB2 Laves phase was closely related to the compositions of the alloys. The cycle life of Ti-based electrode alloy could be enhanced in certain degree by rapid quenching. For Ti-Zr-based electrode alloy, its cycle life could be exalted dramatically with the increase of quenching rate. The main reason of different influence of rapidly quenching on the cycle stability of the electrode alloy was attributed to that the quantities of the amorphous formed by rapid quenching in alloys were different.
    20  Grain-Refining Mechanism of ECAP and Its Effect on Microstructures and Mechanical Properties of Pure Al
    Zheng Lijing Chen Changqi Zhou Tietao Liu Peiying Zeng Meiguang
    2004, 33(12):1325-1328.
    [Abstract](1415) [HTML](146) [PDF 0.00 Byte](4)
    Abstract:
    采用 ECAP 方法和 3 种工艺路径,研究纯铝的显微组织和力学性能的变化。研究发现,对于φ-120°模具来说,在 3 种工艺路径中,路径 A 的晶粒细化效果最明显,其次为路径 Bc,路径 C;6 次 ECAP 后,采用路径 Bc 试样的显微组织由等轴晶组成,而采用路径 A 和路径 C 时试样的显微组织由拉长的纤维状晶粒组成,平均晶粒尺寸均能小于 1 μm。相应地,3种工艺路径提高强度的有效性依次为路径A,路径Bc,路径C,变形过程中σ0.2同晶粒尺寸的关系符合Hall-petch关系。ECAP 过程中纯铝的强化机制主要是细晶强化,并初步探讨了 ECAP 过程中细晶的形成机制。
    21  Effect of Al Content on the Microstructure and Stress Rupture Properties of DS Ni3Al Based Alloy
    Li Shusuo Zheng Yunrong Han Yafang Song Liguo Su Xikong
    2004, 33(12):1329-1332.
    [Abstract](1388) [HTML](142) [PDF 0.00 Byte](0)
    Abstract:
    研究了铝含量对定向凝固Ni3Al基合金铸态和热处理态显微组织的影响,用定向凝固技术制取合金。测试了合金的高温持久性能,利用SEM,EDS,XRD等考察了持久断裂试样的微观形貌。结果表明,铝含量在6.5%~9.5%(质量分数,下同)范围内,合金的铸态组织由γ′,γ和MC碳化物组成,9.5%Al的合金形成大量的γ′初晶和少量β—NiAl相;1300℃,4h固溶热处理使次生γ′全部固溶,共晶γ′固溶很少,直到合金初熔γ′初晶和β—NiAl相仍不能固溶,严重损伤合金的高温强度;在1100℃,70MPa条件下持久时间高于10h时,合金即出现明显的筏排组织,持久裂纹主要沿柱晶横向段和枝晶间萌生扩展。7.5%~8.5%的铝含量是添加了W,Mo,Ta,Ti等合金元素的定向凝固Ni3Al基合金的适宜范围。
    22  Characterization of the LaNi5-38% Mg Alloy Synthesized by Mechanical Alloying
    Meng Mianwu Liu Xinyu Cheng Jun Zhou Huaying
    2004, 33(12):1333-1336.
    [Abstract](1394) [HTML](133) [PDF 0.00 Byte](0)
    Abstract:
    采用机械合金化合成了新型合金LaNi5—38%Mg(质量分数,下同),并采用X射线衍射(XRD),扫描电子显微镜(SEM),差热分析(DTA)等对其结构、形貌及热稳定性能等进行了表征。结果表明:经280r/min球磨250h后,LaNi5—38%Mg合金由非晶和MgNi2纳米晶(5.4nm)组成:所得粉末大多数为规则的近球形或球形,另有少量的多角形或梨形,其粒径为0.05μm~13.9μm,其中90%的颗粒为0.5μm~2.0μm。球磨试样经763K保温35d,获得了热稳定性较好的具有纳米尺度(25.3nm)的三相合金。
    23  Effect of Mn and Zr on Microstructures and Properties of New Type Al-Mg-Si-Cu Alloys
    He Lizi Chen Yanbo Cui Jianzhong Zhang Xiaobo Hu Zhuangqi
    2004, 33(12):1337-1340.
    [Abstract](1364) [HTML](137) [PDF 0.00 Byte](12)
    Abstract:
    The effect of Mn and Zr on the microstructures and properties of new type Al-Mg-Si-Cu alloys were studied, the type and composition of the precipitates were analyzed by XRD, EDAX and TEM. The results showed that the strength decreased and ductility increased with adding Zr. Adding both 0.03%Mn and 0.08%Zr, granular or rod AlCrMnFeSi dispersoids were present profusely in the microstructures of the alloy-T6, both the strength and ductility of the alloy increased. Continuously increasing Mn and Zr, the properties decreased due to the reduce of precipitate-strengthening phase Mg2Si and the occurrence of coarse AlCrMnFeSi.
    24  Effect of Heat Treatment on the Peel Strength of Two Kinds of Cu Film
    Liang Tongxiang Liu Yangqiu Zhang Shiji
    2004, 33(12):1341-1343.
    [Abstract](1539) [HTML](140) [PDF 0.00 Byte](1)
    Abstract:
    Copper-polyimide specimens were presented by chemical vapor deposition (CVD) and physical vapor deposition (PVD) methods, and TiN thin films were deposited by PVD as a diffusion barrier. TiN barriers have shown to be very effective against copper diffusion. The effect of annealing treatment on the adhesion characteristics of copper films were studied. CVD copper films showed small residual stress and high adhesion strength, but for PVD copper film, much residual stress left in copper film when TiN barrier was used. The adhesion improvement by annealing treatment was attributed to the removal of tensile residual stress in copper films in Cu/TiN/PI.
    25  Study on Microstructure and Mechanical Properties of Solid-Phase Joined MB3 Magnesium Alloy
    Wang Kuaishe Liu Junshuai Xu Kewei Shen Yang
    2004, 33(12):1344-1346.
    [Abstract](1246) [HTML](136) [PDF 0.00 Byte](11)
    Abstract:
    研究了MB3镁合金的搅拌摩擦焊技术。对其塑性连接时的焊缝成形,焊缝组织形态及接头的力学性能进行了分析。结果表明,用搅拌摩擦焊方法焊接MB3镁合金,当工艺参数合适时,可获得外观成形美观、内部无缺陷,几乎无变形的平板对接接头。接头力学性能试验表明,其抗拉强度可达母材的97.2%,高于熔焊接头的强度,断裂位置大多位于热影响区。
    26  The Effect of the Ion Pd2+ on the Chemical Stability of the TiO2 Photocatalyst Thin Films
    Xu Ailan Hui Chun Xu Xiaobing
    2004, 33(12):1347-1350.
    [Abstract](1429) [HTML](163) [PDF 0.00 Byte](8)
    Abstract:
    采用Sol—Gel工艺在普通玻璃表面制备出均匀、透明的添加0.3%~0.5%贵金属Pd^2 的TiO2-SiO2复合薄膜。通过对薄膜的XRD,SEM表征及薄膜耐酸、碱化学稳定性的检测,结果表明,在TiO2—SiO2薄膜中添加Pd^2 ,增强了TiO2薄膜的光催化活性,由于Pd^2 所起到阻滞剂的作用,使晶粒尺寸减小,表面呈多孔合理结构,改善了TiO2薄膜的显微结构,使薄膜的化学稳定性得到明显的提高。
    27  Double-Glow Discharged Plasma Non-Hydrogen Carburizing on Titanium Alloy Surface
    Li Zhengxian Zhou Hui Du Jihong Xu Zhong Zhou Lian
    2004, 33(12):1355-1357.
    [Abstract](1264) [HTML](148) [PDF 0.00 Byte](0)
    Abstract:
    采用双层辉光无氢离子渗碳技术在本底真空为 5×10-3Pa 的情况下,用 99.999%的高纯氩气对 Ti-6Al-4V 钛合金进行无氢渗碳。检测结构为:渗碳层厚度大于 200μm;表面层有一层以 TiC 为主的沉积层;在渗层中有 TiC 相生成;渗层的近表面硬度为 7 000 MPa;与刚玉球的摩擦力矩大幅度降低。通过研究得出:钛材经过双辉离子无氢渗碳后,不仅提高了表面的硬度,同时降低了摩擦系数,因而使耐磨性能得到了提高。
    28  Preparation of Nanometer-Sized CeO2-Doped Nanoglass
    Wang Jinxian Dong Xiangting Yan Jinghui Feng Xiuli Liu Zhongxin Hong Guangyan
    2004, 33(12):1358-1361.
    [Abstract](1326) [HTML](137) [PDF 0.00 Byte](10)
    Abstract:
    采用溶胶-凝胶技术制备了掺杂纳米CeO2的纳米玻璃,探索了不同溶剂、pH值、热处理温度和升温速率等制备条件对纳米玻璃的影响,获得了最佳的制备条件,得到了透明的掺杂纳米CeO2的纳米玻璃。其中反应物最佳摩尔比为:nTEOS:ni-PrOH:nEOH:nH2O=1:2:1:20;最佳pH值为:1.4~118;凝胶化的理想环境为:T65℃~70℃,润湿气氛;制备干凝胶的最佳热处理路线为:水浴70℃,3d→水浴85℃,3d→烘箱100℃,1d→烘箱150℃,2d。因此,溶胶-凝胶技术是制备纳米玻璃的有效途径。
    29  The Existing Form of Nb in Zr-Sn-Nb-Fe Alloys and Its Dependence on Intermediate Annealing
    Li Zhongkui Zhou Lian Zhang Jianjun Wang Wensheng Jin Zhihao
    2004, 33(12):1362-1364.
    [Abstract](1438) [HTML](145) [PDF 0.00 Byte](1)
    Abstract:
    用 SEM 的波谱(WD)分析手段,定性研究了合金元素铌在 Zr-Sn-Nb-Fe 合金中的存在方式及其与中间退火工艺的关系。研究结果表明添加的合金元素铌主要存在于 Laves 相中,并且随中间退火温度升高,第二相中铌含量增加。铌在 α-Zr 中的含量随退火温度升高而降低,可降低至小于 1×10-4,这与二元 Zr-Nb 合金中合金元素铌的固溶度随温度升高而增加明显不同。铌和铁、铬共存于锆合金中时,将与铁、铬一起优先形成沉淀相,导致合金元素主要存在于第二相中,并出现其在 α-Zr 中固溶量随退火温度升高而降低的现象;其原因可归结为随退火温度升高铌扩散能力增加,从而导致在第二相中含量增加。

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