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1.
1INTRODUCTIONMetalhydrideshavebeenusedasnegativeelectrodesofnickel/metalhydridebateriesinplaceofcadmium,becauseoftheirhighene...  相似文献   

2.
1 INTRODUCTIONElectricfurnacetransformerisanimportantelec tricequipmentintheprocessofnickelsmelting ,buttheconventional/centralized protectioncannotmeettheneedforreliabilityandsecurity ,anditsprelimi naryequipmentisevolvingtowardsthedirectionofdigitalful…  相似文献   

3.
1 IntroductionThestructureandelectrochemicalpropertiesofnickelhydroxidehavebeenstudiedextensivelyduetoitsimportanceasactivematerialsinnickelbatterysys tems[1 ].Afundamentalunderstandingoftheeffectsofmetallicadditivesandimpuri tiesonthenickelhydroxideelec…  相似文献   

4.
1IntroductionNickelmatteproducedfromnickelconvertersmeltingisanintermediatefortheproductionofmetallicnickelandcopper.Itprincipallyconsistsofsulfidesofnickelandcopper,andminoramountofnickelcopperalloy.Hydrometallurgicalprocessinghasbecomepopularinrefini…  相似文献   

5.
1 INTRODUCTIONNi Tabinaryalloyhasbeenthesubjectofmuchresearchowingtoacombinationofscientificandtech nologicalinterest .Ononehand ,t  相似文献   

6.
Simulation and prediction of microstructure in hot forming of metals   总被引:1,自引:0,他引:1  
1 INTRODUCTIONInrecentyears,therehasbeengrowingneedinthemetalformingindustrytoimprovequalityandde creasecostsofproducts.Effectivecontrolofmechani calpropertiesandqualityofproductscanbeachievedbytheunderstandingofdeformationconditionsandmicrostructuralc…  相似文献   

7.
Dislocation evolution with rheological forming of metal   总被引:7,自引:4,他引:3  
1 INTRODUCTIONUntilnow,formostoftheappliedengineeringmaterials,therewouldbesomeinternaldefectsinthem;forexamples,impurities,cracks,cavities,pointdefectssuchasdisplacedatomorforeignmatteratoms,andlinedefectssuchasdislocation,planedefectscausedbypiled…  相似文献   

8.
1 INTRODUCTIONAvibrationcausedbyarollingmillnotonlyaf fectsthesmoothnessandsteadinessoftherunningmill,butalsoaffectsthequalityoft  相似文献   

9.
INTRODUCTIONTheABO3oxideswithperovskitebasedstructureofMnserieswhichhaveCMRefectshavebenthesubjectsofintensiveresearcheffor...  相似文献   

10.
1 INTRODUCTIONFundamentalelectrochemicalinvestigationsrelat edtosulfidemineralflotationhavebeenwidelyre portedforalongperiodoftime[1] .Recently ,effectsandcontrolofpotentialinlaboratory scaleflotationtestsofsulfidemineralsandoreshavedrawnsomeat tentions[2~ 9…  相似文献   

11.
The results are presented of a quantitative study of the phosphoric acid anodizing of high purity aluminium. The effects of electrolyte concentration, temperature, anodizing time, current density and air agitation on the coating weight, metal loss, coating ratio and density of the anodic coating were investigated.

The use of phosphoric acid anodic coatings as a base for electrodeposition is discussed with particular reference to plating in a copper pyrophosphate solution and the growth of copper deposits in the anodic film. Tests on chromium/nickel/copper electrodeposits on 38 aluminium alloy are briefly described.  相似文献   

12.
The anodic overvoltage of neodymium electrolysis was determined by slow scanning oscillograrn. The effects of some factors, i.e. the temperature, the anodic current density, the concentration of Nd2O3 and the components of the electrolyte were investigated and the approaches to decrease the anodic overvoltage were also discussed. The results show that the anodic overvoltage increases with the anodic current density and decreases with the increasing temperature. The linear relation between the anodic overvoltage and the current density corresponding to Tafel equation is determined to some extent. The anodic overvoltage decreases with the increasing concentrations of LiF and NdF3. It also decreases by controlling the anodic current density properly, increasing the temperature or the concentrations of LiF and NdF3 and the reducing polar distance.  相似文献   

13.
Ar与H2混合气体保护下GTAW电弧特性数值模拟   总被引:1,自引:1,他引:0  
针对Ar与H2混合气体保护下GTAW焊接电弧的传热与流动特性,建立基于磁流体动力学的二维轴对称数学模型,结合麦克斯韦方程组与流体动力学理论对电弧的温度、电势、电弧压力以及电流密度等进行求解,又分别将传统氩弧与氩氢混合气体保护下电弧的阳极热进行分析与对比.结果表明,加入10%氢气后的电弧轮廓较传统氩弧略微收缩,电磁力增至约传统氩弧的2倍,温度、等离子体流速、电势、电流密度等都明显增大,导致更多热量传递给阳极,在一定程度上提高了焊接热效率.可为高效GTAW焊接工艺的进一步开发提供理论参考.  相似文献   

14.
研究温度对阳极氧化铝薄膜纳米孔自组织过程的影响.使用环境扫描电镜(ESEM)研究了铝试样在硫酸、草酸、磷酸溶液中,于不同电解温度下阳极氧化形成的氧化铝薄膜形貌.通过分析阳极氧化时电流密度与时间关系曲线,研究了温度对阳极氧化铝薄膜纳米孔自组织过程的影响.提出降低电解温度能够缩短纳米孔自组织过程的时间,是由于降低电解温度增大了纳米孔内表面的表面张力.并且提出在不同的电解质溶液中,电解温度对纳米孔自组织过程的影响程度不同,电解温度对纳米孔自组织过程的影响以在硫酸溶液中最敏感,草酸次之,在磷酸溶液中的影响最小.  相似文献   

15.
稀土对6063铝合金阳极氧化膜厚度的影响   总被引:5,自引:0,他引:5  
在硫酸、硫酸亚锡溶液中对添加稀土的6063铝合金进行阳极氧化和电解着色,系统地研究了氧化电解液浓度、温度、时间、电流密度对膜层厚度的影响.结果表明:稀土可以明显地提高6063铝合金氧化膜厚度,稀土含量以0.20%为好.  相似文献   

16.
The effect of different concentrations of sodium borate, current densities, pH and temperature on the anodic oxidation of nickel was studied using galvanostatic polarization technique. The anodic potential-time curves showed four regions: the charging of the anodic double layer, an arrest corresponding to anodic dissolution and/or oxide film formation, linear rise in the potential due to the formation of barrier oxide film and finally deviation from linearity to reach steady-state potential value attributed to oxygen evolution reaction. The duration time of the arrest decreases with increasing current density and concentration of borate anion while the rate of oxide film formation increases. On the other hand, the duration time of the arrest increases with increasing pH and temperature of the solution while the rate of oxide film formation decreases. Increasing the borate concentration and pH of the solution shifted the starting potential of the arrest towards more negative values. Linear relationships were obtained between the starting potential of the arrest and both borate concentration and pH.  相似文献   

17.
次亚磷酸钠体系化学镀镍的电化学研究   总被引:2,自引:0,他引:2  
王美媛  旷亚非 《腐蚀与防护》1999,20(8):339-342,372
运用阳极扫描法他次亚磷酸钠体系化学镀镍在镍电极上的电化学行为。结果表明,化学镀镍的两个部分反应之间存在的强烈的相互作用; 亚磷酸钠的直接氧化产物不是H3PO3,其氧化行为受自身浓度、溶液温度、pH、扫描速度以及Ni^2+浓度的影响。  相似文献   

18.
介绍了泡沫铝阳极氧化工艺,通过试验对比分析了KD-SY酸蚀工艺和碱蚀工艺的差异,探讨了泡沫铝阳极氧化过程中,硫酸浓度、电流密度、温度、Al3+浓度、杂质元素对阳极氧化膜的影响.  相似文献   

19.
介绍泡沫铝阳极氧化工艺。通过试验分析对比WL-SY酸蚀工艺和碱蚀工艺的差异,探讨泡沫铝阳极氧化过程中硫酸浓度、电流密度、温度、Al3+浓度、时间、杂质元素对阳极氧化膜的影响。  相似文献   

20.
Growth and dissolution of anodically obtained oxide layers on titanium Oxide films were grown by anodic polarization of titanium in various aqueous electrolytes. The field strength derived from film thickness and voltage is linearly related to the logarithm of the total current density. The current efficiency for film formation depends upon current density, pH-value, and film thickness. The dielectric constant of the film decreases with field strength from ε = 110 to ε = 7, but rises again at high field strengths and thick films. The dissolution rate of anodic oxide films on titanium was investigated as a function of pH-value, concentration of chloride, and temperature, respectively. Aging of the films in distilled water causes the dissolution rate to decrease by up to 3 order of magnitude.  相似文献   

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