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在弱碱性及中性介质中AISI304不锈钢载波钝化膜光电化学研究 总被引:3,自引:0,他引:3
采用光电化学方法-恒电位光电流测量技术研究了AISI304不锈钢在0.1mol/LNa2B4O7及0.5mol/LNa2SO4介质中载波钝化膜,光电流测量结果表明,光电流大小与电极电势、成膜条件及测量介质有关,载波钝化膜基本上是高度无序的非晶态膜。 相似文献
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在具有CeO2隔离层的Si基片上获得了较高质量的YBa2Cu3O7-x(YBCO)高温超导薄膜。在零磁场下,77K时其临界电流密度达到1×106A/cm2。研究发现,YBCO的(001)面平行于Si基片的(100)面,而CeO2过渡层由许多约40nm×100nm的细小CeO2晶粒组成,其取向呈散乱分布。尽管CeO2和Si之间的晶格错配很小(约0.4%),CeO2却不能在Si上外延生长,而YBCO却能在取向凌乱的CeO2上形成[001]择优取向。CeO2和Si的界面处有一层极薄的过度层。YBCO和CeO2界面存在Y2BaCuO5(211相)。在YBCO薄膜中观察到有与123相混生的248相。 相似文献
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用于燃料电池的Bi2O3基稀土固体电解质的研制 总被引:2,自引:0,他引:2
合成了(Bi2O3)0.75(Y2O3)0.25和(Bi2O3)0.65(Gd2O3)0.35固体电解质陶瓷材料;测试了其晶体结构,XPS谱及在500 ̄800℃的离子电导率随温度的变化;组装了镀有ZrO2-Y2O3保护膜的Bi2O3基稀土固体电解质燃料电池。 相似文献
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电沉积烧结ZrO2—8wt%Y2O3薄膜及其对AISI304不锈钢高温氧化行… 总被引:4,自引:0,他引:4
在水溶液中于AISI304不锈钢表面电沉积Zr(OH)4-Y(OH)3薄膜,然后在300 ̄500℃烧结形成ZrO2-8wt%Y2O3薄膜,讨论了相应的机理。研究结果表明,表面沉积ZrO-8wt%Y2O3薄膜的试样与空白试样相比,氧化增重下降约3倍,表面沉积ZrO2-8wt%Y2O3薄膜有益作用在于改善了氧化膜与不锈钢基体的附着力和促进铬的选择性氧化。 相似文献
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以硅溶胶为硅源.在0.301,12-烷基二胺-XNa2O-YAl2O3-SiO2-ZH2O体系中,研究ZSM—11沸石于160~200℃区间的水热结晶.用XRD鉴定产物.合成纯相ZSM-11的反应物配比是X=0.05;Y=0~0.011;Z=40.其反应温度为160~180℃.加入ZSM-11晶种或添加NaF可加快结晶速度,导致ZXS-11(silicalite-Ⅱ)柱状单晶的生成.该单晶的最大尺寸可达20×20×60μm. 相似文献
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以硅溶胶为硅源,在0.301,12-烷基二胺-XNa2O-YAl2O3-SiO2-ZH2O体系中,研究ZSM-11沸石于160~200℃之间的水热结晶。用XRD鉴定产物,合成纯组ZSM-11的反庆物配比是X=0.05;Y=0-0.011;Z==40。其反应温度为160~180℃。加入ZSM-11晶种或添加NaF可加快结晶速率,导致ZXS-11柱状单晶的生成。该单晶的最大尺寸可达20×20×60μm 相似文献
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采用溶胶-凝胶(Sol-Gel)法制备了微孔结构均匀的“SiO2/陶瓷”膜和“Mo-Co-O/SiO2/陶瓷”催化功能膜,并用XRD、SEM和孔径测定等技术进行了表征。在常压,500~700℃的条件下,在催化膜反应器(CMR)中考察了甲烷氧化制甲醇的反应。在相似的反应条件下(转化率为1.0%),用CMR(甲醇选择性1?.2%)可获得较固定床反应器(甲醇选择性4.5%)高得多的甲醇选择性。 相似文献
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采用浸渍法制备了La2O3,TiO2,ZrO2以单层状态分散在SiO2,Al2O3上的改性载体。用XPS求得它们的最大单层分散阈值为:0.22gLa2O3/100m^2SiO2,0.27gLa2O3/100m^2Al2O3,0.04gTiO2/100m^2SiO2,0.036g TiO2/100m^2Al2O3,0.07gZrO2/100m^2SiO2,0.08gZrO2/100m^2Al2O3. 相似文献
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载波钝化和钼酸盐后处理对不锈钢钝化膜性能的影响 总被引:1,自引:1,他引:1
一般认为交流电对金属的腐蚀过程具有加速作用,但我们发现,在直流电位基础上叠加适当波形、幅值和频率的交流电对不锈钢进行载波钝化,尔后再进行适当后处理可使钝化膜的稳定性提高,我们曾就不经后处理的载波钝化过程进行过探讨,本文着重探讨钼酸盐后处理对载波钝化膜表面状态和化学稳定性改善的作用机理。 相似文献
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Electrochemical impedance spectroscopy and XPS studies on AISI 304 stainless steel in naturally aerated 0.5 M H2SO4 solution were carried out at room temperature. The valuable model of the metal/solution interphase was established, and the reliable equivalent electrical circuits in the solution were presented. The analysis of the chemical composition of passive film on AISI 304 stainless steel was carried out by XPS. The passive film of AISI 304 stainless steel is composed of oxyhydroxides, Fe2O3, FeO, Cr2O3, NiO, sulfate, sulfite, and sulfide (FeS, NiS). It is reported that the ferrous sulfide film formed on AISI 304 stainless steel in the dilute sulfuric acid solution. The possible process in which sulfuric acid is reduced to sulfite and sulfide is proposed. The galvanic interaction of sulfide inclusions with the base alloy is introduced. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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控制金属材料的腐蚀或磨损有三种方法:1)合理选用耐蚀金属材料(包括开发新材料或对材料进行适宜的表面强化处理;2)改善金属材料服役的介质环境(包括合理使用缓蚀剂);3)采取电化学保护措施.由于在腐蚀介质中工作的各种摩擦副往往受腐蚀与磨损的协同作用而发生... 相似文献
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Electrochemistry methods were used to investigate the influence of pH on the passive film and corrosion behavior of ultrahigh strength AM355 stainless steel in chloride-containing media. Analysis of the Pourbaix diagram indicates that AM355 stainless steel exhibits higher corrosion resistance in natural and near-natural environments than that in acidic and alkaline conditions. Electrochemistry measurements and composition analysis of the passive film show that pitting potential increased due to the enhanced repassivation capacity of AM355 stainless steel with increasing pH. The mixed MnS/oxide inclusions are the main pitting sensitive locations under all conditions. Morphological observations and energy-dispersive spectroscopy showed that the influence of the gap between the martensitic laths is significant with increasing pH. The inclusions, element concentrations, and microstructures weaken the resistance of ultrahigh-strength martensitic AM355 stainless steel against corrosion. 相似文献
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模拟冷却水中不锈钢的自钝化及硫离子的影响 总被引:3,自引:0,他引:3
通过对316#不锈钢/模拟冷却水体系电化学阻抗谱(EIS)的测定和拟合,确定了合适的模型.根据此模型,膜电阻R2在电极浸泡过程中增大, 反映膜电容的Y02值则不断减小,显示钝化膜的增厚和致密.模拟冷却水中硫离子的加入使R2迅速降低.Mott-Schottky图测定显示,在模拟冷却水中浸泡65天的不锈钢钝化膜的施主密度ND和受主密度NA分别为1.47×1020和2.20×1020 cm-3,加入9 mg•L-1硫离子1 h后, ND和NA分别上升到4.52×1020和7.02×1020 cm-3.极化曲线测定表明9 mg•L-1硫离子使不锈钢钝态电流增大了近一倍. 相似文献
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借助于Mott-Schottky方程分析了成膜电位、成膜时间、成膜温度以及氯离子等因素对22Cr双相不锈钢在碳酸氢钠/碳酸钠缓冲溶液中所成钝化膜半导体性能的影响, 同时借助于X射线光电子能谱(XPS)技术分析了所成钝化膜的组成. 结果表明: 22Cr双相不锈钢在碳酸氢钠/碳酸钠缓冲溶液中所成钝化膜呈n-p型半导体结构, 钝化膜内施主/受主密度随成膜电位增加、成膜时间延长、成膜温度降低、以及介质中氯离子浓度的降低而减小, 同时膜对基体保护作用随这些因素变化而增强. 钝化膜的XPS分析表明, 钝化膜呈现双层结构, 外层膜主要由三价铁的氧化物(Fe2O3)组成, 内层膜主要由三价铬氧化物(Cr2O3)以及少量二价铁氧化物(FeO)组成. 相似文献
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《Electrochemistry communications》2007,9(1):76-82
In the present paper we show that a significant improvement in pitting corrosion resistance of a biomedical grade stainless steel, 316LVM, can be achieved by the formation of a surface passive oxide film under cyclic potentiodyanamic polarization (passivation) conditions. A complete absence of pitting in physiological simulating solutions was demonstrated, while the electrochemically formed passive film maintained its very high pitting resistance even at higher chloride concentrations in the bulk solution. The improvement in the film’s pitting corrosion resistance was correlated with its semiconducting properties. 相似文献
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