沥青调制温度对活性炭材料结构及电容特性的影响

以煤焦油沥青为原料，在不同温度下调制得到碳质微晶结构的中间相沥青，采用化学活化法制得超级电容器用高比表面积活性炭。以制备的活性炭作电极材料组装模拟电容器，6mol／LKOH溶液为电解液，考察了中间相沥青的调制温度对活性炭结构和电容行为的影响。结果表明：随着调制温度的提高，活性炭比表面积先增加后减小，在450℃时达到最大值，为3250m^2／g；制备的活性炭孔径主要集中在14nin范围内：在350℃时，无定形结构的中间相沥青有利于扩孔，制得的活性炭具有较高的中孔含量：随着调制温度的继续提高，中孔含量下降：活性炭比电容量随着调制温度的提高先增大后减小，450℃时达到最大值，为215F／g。     

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.     

溶胶-凝胶法制备的ZnO:Al薄膜的微观结构及光学、电学性能

采用溶胶-凝胶法制备了ZnO:Al(AZO)透明导电薄膜．通过X射线衍射(XRD)、紫外-可见分光光度计 (UV-Vis)、扫描电镜(SEM)和电阻测量装置,考察了Al掺杂量、退火温度及镀膜层数等工艺参数对薄膜的微观结构和光电性能的影响．结果表明,退火温度越高,多晶AZO薄膜的(001)晶面择优取向生长的趋势越强,并且随退火温度升高,薄膜的晶粒尺寸增大,透光率增加．薄膜晶体结构为纯ZnO的六角纤锌矿结构．在掺杂浓度1％(摩尔分数)、退火温度500℃及镀膜层数10的条件下,得到了电阻率为3．2×10-3Ω·cm、可见光区的平均透射率超过90％的AZO薄膜．     

2．1NaF·AlF_3─NaCl─MgF_2熔盐体系初晶点及电导率的研究

本文采用二因子二次回归正交设计研究了２．１ＮａＦ·ＡｌＦ３—ＮａＣＩ一ＭｇＦ２熔盐体系的初晶点及９４０℃时体系的电导率，用数理统计分析法得到了初晶点及电导率随体系中ＮａＣｌ和ＭｇＦ２含量变化而变化的二元二次方程．试验结果表明，体系初晶点随ＭｇＦ２含量增高而降低；而随ＮａＣｌ含量变化出现极大值，极大值点随ＭｇＦ２含量变化而变化，越过极大值点，初晶温度随ＮａＣｌ含量增加而下降．体系电导率随ＮａＣｌ含量增加而增大，而随ＭｇＦ２含量的变化出极大值，越过极大点电导率随ＭｇＦ２增加而减少。     

热震作用对硬质合金力学性能的影响及其失效机理

研究热震作用对3540和3475硬质合金抗弯强度、断裂韧性以及硬度的影响.结果表明,硬质合金抗弯强度和断裂韧性随热震次数呈先升后降变化,硬度随热震次数增加略有下降.这是由于淬火抑制了fcc γ→hcp γ相变,粘结相的固溶强化,γ相平均自由程λγ增大以及热震热应力的共同作用的结果.3540和3475合金热震后断面的粗糙度降低,孔洞增多,沿晶断裂比例增加.热震后合金表面发生氧化,形成疏松的氧化层,3540合金抗氧化能力比3475合金高.同时,还观察到游离碳聚集区的碳元素发生扩散,留下大量孔洞,在WC/Co界面处形成大量小裂纹.     

硬质合金强度随温度的变化及失效机理的研究

研究了温度对3555和471硬质合金抗弯强度的影响.结果表明,3555和471硬质合金的抗弯强度在室温至300℃的范围内基本保持不变,在300～400℃开始下降,在400～500℃范围内剧烈下降,在500～600℃范围内下降变缓,在600～700℃时,抗弯强度值出现一个平台,比室温时强度降低30%左右.这是由于高温下合金的软化,hcp γ→fcc γ相变,W、C在粘结相中的固溶以及热应力共同作用的结果.3540和3475合金高温下断面的粗糙度降低,孔洞增多,沿晶断裂比例增加.高温下合金表面发生氧化,形成疏松的垂直于表面生长的柱状晶氧化层,3555抗氧化能力比471合金高.     

碳还原法制备电解电容器用一氧化铌粉末

一氧化铌(NbO)具有与金属相近的导电能力,作为阳极赋能时,与铝、钽、铌等阀金属一样,能在阳极表面形成介电性能优良的无定型氧化膜。研究了真空碳还原Nb2O5制备NbO的原理、工艺条件以及一氧化铌粉末的理化性能和电性能等,参照GB/T3137-1995关于电容器用钽粉电性能测试方法,经实测,一氧化铌粉末具有比电容105120μF·V/g,损耗11.2%,漏电流2.5×10–4μA/μF·V,表明其湿式电性能已达到甚至优于相应的高比容钽粉的水平;沿用钽电容器生产工艺,探索性地进行了小批量以NbO为阳极的电解电容器生产,其成品合格率达到77%。     

Microstructure and mechanical properties of 8YSZ ceramics by liquid-phase sintering with CuO-TiO2 addition

The 8% (mass fraction) yttrium-partially-stabilized zirconia (8YSZ) ceramic was fabricated via liquid phase sintering at 1 200–1 400 °C by adding different mass ratios of CuO-16.7%TiO₂ (molar fraction) as sintering aid. Relative density, microstructure, Vickers hardness and bending strength as a function of sintering temperature and additive content were investigated. The experiment results show that liquid phase sintering at low temperature can be realized through adding CuO-16.7% TiO₂ to 8YSZ. The Vickers hardness and bending strength of samples with sintering aid are generally much higher than those of samples without sintering aid for all sintering temperatures, and increase with the increase of sintering temperature. When the addition content of CuO-16.7% TiO₂ is beyond 0.5%, the relative density, Vickers hardness and bending strength decrease with the increase of the mass ratio of sintering aid. Low additions of sintering aid are beneficial to aiding densification; high additions of sintering aid are detrimental to the sintered properties mainly due to greater amounts of pores generated by the volatilization of oxygen with the eutectic reaction between copper oxide and titanium dioxide. It is found that the fine grain size and high relative density are two main reasons of the high bending strength and Vickers hardness of the materials.     

超细碳化钨粉末粒度测试方法的研究

应用显微镜法(SEM、TEM)、激光粒度法、X射线线宽法、比表面积法对自制超细碳化钨粉末粒度进行测量,探讨了测量原理、颗粒形状等因素对粒径测试准确度的影响。通过对实验结果的分析,研究对比了几种超细微粒表征手段的优越性和局限性。     

新型复合材料离子交换树脂粒度性能的研究与测定

采用激光粒度分布仪结合扫描电镜对SP-1、SP-2及SP-C新型复合材料离子交换树脂粒度性能进行了研究测定。结果表明：SP-1有效粒径为161．12μm，均一系数为1．36；SP-2有效粒径为129．7μm，均一系数为1．67；SP-C有效粒径为130．79μm，均一系数为1．73。扫描电镜观察显示，树脂中的细颗粒主要来源于颗粒的碎化。