材料烧结点测试系统及其图像处理

本文论述了材料烧结点测试系统的工作原理及其组成。采用数字图像处理技术 ,引入高速A/D转换及计算机系统 ,以实现对材料烧结点进行高效、可靠的测试。测试结果表明 ,这是一个实用的计算机自动检测系统。     

Thermal expansion anomaly and spontaneous magnetostriction of Dy2AlFe14Mn2 compound

The structure and magnetic properties of Dy₂AlFe₁₄Mn₂ compound were investigated by X-ray diffractometry and magnetization measurements. Dy₂AlFe₁₄Mn₂ compound has a hexagonal Th₂Ni₁₇-type structure. Zero thermal expansion and negative thermal expansion were found in Dy₂AlFe₁₄Mn₂ compound in the temperature range from 184 to 264 K, and from 264 to 383 K, respectively, by X-ray dilatometry. The spontaneous magnetostrictive deformations from 104 to 400 K were calculated. The results show that the spontaneous volume magnetostrictive deformation increases firstly with increasing temperature, and then decreases with further increasing temperature.     

离子束增强沉积CrN膜层及其微动摩擦学性能研究

以不同氮离子辅助轰击能量制备CrN膜层．利用纳米压入仪及显微硬度计分别测试单晶Si片上膜层的硬度及断裂韧度K1C．使用XRD、XPS及EPMA分析离子轰击能量对镀层组织结构的影响。结果表明，采用能量较低的氮离子轰击得到的涂层，由于金属Cr的存在，涂层硬度虽有所降低，但断裂韧度K1C数值较高。选择较低的4keV辅助轰击能量，在M2高速钢基体上沉积CrN涂层，膜层在空气介质中表现出优异的耐磨减摩特性.但在水介质条件下，由于膜层接触区域的去钝化，再钝化使腐蚀和磨损相互加速，导致CrN膜层摩擦系数，尤其是磨损量明显高于基材。     

短碳纤维表面化学镀铜工艺研究

实验用NaOH对短碳纤维亲水化处理，无需敏化、活化等工艺直接放入镀液中化学镀铜，研究了镀液温度、pH值和装载量对镀层质量的影响。用光学显微镜观察了镀层的表面质量。结果表明，当温度为60℃，pH值为13，装载量为0．1g／60ml时．获得的镀层光滑致密。     

稀土、锶复合添加对AM60镁合金组织和性能的影响

稀土、锶复合添加对AM60镁合金组织、力学性能和抗热裂性能的影响的研究结果表明,往AM60镁合金中添加稀土后,稀土与合金中的异质形核核心Al9Mn11相或Al(8Fe,Mn)5相反应生成Al-RE-Mn三元相,减少了合金熔体中异质形核核心的数目,从而引起了合金晶粒粗化。往AM60镁合金中复合添加稀土和锶后,锶能够消除稀土引起的晶粒粗化作用,减少晶粒粗化对合金力学性能和抗热裂性能的不利影响,从而提高合金的高温屈服强度,并消除稀土对合金抗热裂性能的恶化作用。     

Internal oxidation thermodynamics and microstructures of Ag-Y alloy

The thermodynamic data of pure Ag and Y were calculated. The phase constitution, composition of micro-region and microstructures of Ag-Y alloy after internal oxidation were investigated by X-ray diffractometry(XRD), energy dispersion spectrometry(EDS) and scanning electron microscopy(SEM). The results show that the internal oxidation behavior of Ag-Y alloy is feasible from the view of thermodynamics. The upper limit of oxygen partial pressure of Ag-Y alloy oxidation is a function of temperature. Two phases (Ag and Y2O3) appear in Ag-Y alloy after the internal oxidation. The surface of Ag-Y alloy is convex because of the volume expansion of oxide in the alloy and the composition of the convex part is Ag. In Ag-Y2O3 sintered bulk Y2O3 particles are distributed inhomogeneously and conglomerated seriously, but they are dispersed uniformly in the Ag matrix after severe plastic deformation.     

2005年上半年我国钛工业的运行情况

2005年上半年，我国共生产海绵钛3801．6t，同比增长68％；生产钛粉342．5t，同比减少了76．5t；生产钛加工材5033．9t，同比增加了17％。2005年上半年，我国海绵钛进口量大幅减少，仅642t，钛加工材却大幅增加，达3024t。尽管从2004年开始，海绵钛及钛加工材价格大幅t涨，但我国对海绵钛和加工材的需求乃明显上升，预计2005年我国海绵钛的需求在万吨左右，而实际产量估计达到9000t左右，与实际需求稍有差距。世界海绵钛的生产能力不断扩大，预计2005年全球海绵钛的供应能力将增加23％，下半年海绵钛价格将趋于平稳。     

变电所屋外构筑物钢结构件的失效分析

采用扫描电镜(SEM)、能谱分析(EDS)、X射线衍射(XRD)、红外分析(FTIR)、热重分析(TGA)等对变电所屋外构筑物钢结构件上的腐蚀产物进行分析表征.结果表明:该腐蚀产物主要为Fe3O4、α-FeOOH的混合物,钢结构件的锈蚀失效是由潮湿大气环境下碳钢材料的电化学腐蚀所引起的.另外,在提高钢结构件的稳定性方面作了一些探讨,提出了合理可行的整修建议.     

High-rate capability of spinel LiNi0.05Mn1.95O4 cathode for Li-ion batteries prepared via coprecipitated precursor

Spinel LiNi0.05Mn1.95O4 cathode material for lithium ion batteries was synthesized by solid-state reaction from coprecipitated Ni-Mn hydroxide precursors and characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM） and galvanostatic charge-discharge tests. It is found that LiNi0.05Mn1.95O4 powder has an ordered cubic spinel phase （space group Fd3m） and exhibits superior rate capability. After 450 cycles, the LiNi0.05Mn1.95O4/carbonaceous mesophase spheres（CMS） Li-ion batteries can retain 96.0% and 93.3% capacity at 5C and 10C charge/discharge rate, respectively, compared with 85.3% （5C） and 80.5% （10C） retention for LiMn204 batteries. However, the initial discharge capacity of LiNi0.05Mn1.95O4/CMS batteries at 1C charge/discharge rate （96.20 mA.h/g） is slightly lower than that of the LiMn2O4 batteries （100.98 mA.h/g） due to the increased average oxidation state of Mn inLiNi0.05Mn1.95O4.     

Preparation and properties of Ce0.8Ca0.2O1.8 anode material by glycine-nitrate process

Ce0.8Ca0.2O1.8（CDC82） anode material was prepared by glycine-nitrate process（GNP）. Thermogravimetric（TG） analysis and differential scanning calorimetric（DSC） methods were adopted to characterize the reaction process of CDC82 material. X-ray diffractometry（XRD）, scanning electron microcopy（SEM）, direct current four probe （four-probe DC） and temperature process reduce（TPR） techniques were adopted to characterize the properties of CDC82 material. After the precursor was sintered at 750℃ for 4 h, CDC82 material with pure-fluorite structure and nanometer size was obtained. The total conductivity of CDC82 changes little with temperature in air at 50-850℃, and the maximum value is 0.04 S/cm at 750 ℃. The total conductivity wholly becomes larger when the atmosphere changes from air to hydrogen, which greatly increases with increasing temperature and reaches the maximum value of 1.09 S/cm at 850 ℃. Some impurities such as CeMg and La203 exist after the mixture of CDC82 anode and La1-xSrxGa1-yMgyO3-δ （LSGM） electrolyte material is sintered at 1 200 ℃ for 15 h. The CDC82 material as anode material has excellent catalytic property for hydrogen and methane.