Corrosion Inhibition Mechanism of Rare Earth Metal on LC4 Al Alloy with Spilt Cell Technique

Inmid1980s,Hintonetal[1～6]foundthata smallamountofCeCl3canobviouslyreducethecorro sionrateof7075aluminumalloyinNaClsolutionand cerium(Ⅲ)saltisregardedastheidealsubstituteof chromates(Ⅵ).Ceriumsalt,asanenvironment fa voredinhibitorofaluminumalloy,hasgainedmore andmoreattention.However,itsinhibitionmecha nismisstillunknown.Basedonthecathodiccoating theory,Hintonetalputforwardrestrictioncathodic reactiontheory[7]thatrareearthcanimprovethecorro sionresistingpropertyofaluminumalloys.Atpresent…     

Preparation and Corrosion Resistance of Rare Earth Conversion Coatings on AZ91 Magnesium Alloy

Magnesiumalloysarewidelyusedinweaponin dustry,spacenavigationandhavegoodpotentialof applicationanddevelopmentindailycommunication facilitiesduetotheirpropertiesoflightweightandhighstrength[1].Appliedasstructuralmaterials,mag nesiumalloysmayeasilycrackduet…     

稀土铈对化学沉积Co-Ni-B合金镀层结构和性能的影响

研究了稀土铈对化学沉积Co-Ni-B合金层化学组成、结构和性能的影响。结果表明：微量稀土铈的加入提高了镀层中钴的含量，降低了镍和硼的含量；使镀层由非晶态转变为品态；稀土铈也明显地提高了镀层的显微硬度，在一定的范围内，镀液中稀土铈添加量越多，镀层的铈含量和显微硬度也越高；稀土铈还提高了镀层的饱和磁化强度，降低了剩余磁化强度和娇顽力，含铈镀层显示出了良好的软磁性能。     

锌镀层表面稀土转化膜成膜机理分析(Ⅰ)

将镀锌层浸泡于以Ce(NO3)3.6H2O为主盐、以30%H2O2为氧化剂的稀土转化膜处理液中,通过计算界面上pH可达到的最大值、Ce-H2O系电位-pH图及Zn-H2O系电位-pH图,推断稀土转化膜可能是由ZnO、CeO2、Ce2O3、Ce(OH)3及Ce(OH)4构成;同时利用X射线光电子能谱仪对该铈盐转化膜表面进行成分分析,结果表明,铈盐转化膜主要是由ZnO、CeO2、Ce2O3、Ce(OH)3、Ce(OH)4构成的复合膜层,这与热力学分析计算相吻合。     

Improving Corrosion Resistance of Cf/Mg Composites using Rare Earth Conversion Coatings

The surface of carbon fiber reinforced Mg matrix (Cf/Mg) composites was modified by treatment of rare earth conversion coating, and nontoxic, non-pollution Ce conversion coatings were prepared. The effect of the coatings on corrosion behaviors of composites was investigated by electrochemical polarization technology and electrochemical impedance spectroscopy (EIS) in 3.5% NaCl solution. The higher Ecorr and lower icorr were obtained by Ce conversion coatings. EIS results showed that the higher values of R2 were obtained by treatment containing CeCl3, the high corrosion resistance occured in treatment containing CeCl3, the low corrosion resistance in uncoating sample, the coating of treatment containing Ce(NO3)3 was medium. The microstructure of Ce conversion coatings was observed by scanning electron microscopy (SEM), and the elements of corresponding for coatings was characterized by energy dispersive spectrometer (EDS). The micro-cracks and Ce-riched spherical particles were characteristics of these coatings.     

Effect of Rare Earth on Superplasticity of Zn—5Al Eutectic Alloy

Zｎ Ａｌａｌｌｏｙｉｓｏｎｅｏｆａｌｌｏｙｍａｔｅｒｉａｌｓｗｉｄｅ ｌｙｕｓｅｄｉｎｉｎｄｕｓｔｒｙ .Ｚｎ 5Ａｌｅｕｔｅｃｔｉｃａｌｌｏｙｉｓｎｏｔｏｎｌｙｅｘｔｅｎｓｉｖｅｌｙｕｓｅｄａｓｄｉｅ ｃａｓｔｉｎｇａｌｌｏｙ ,ｈｏｔｐｌａｔｉｎｇａｎｄｓｐｒａｙｉｎｇａｌｌｏｙ ,ｂｕｔｏｂｔａｉｎｓｒｅｃｏｇｎｉｔｉｏｎｉｎｓｕｐｅｒｐｌａｓｔｉｃｓｈａｐｉｎｇａｎｄｓｕｐｅｒ ｐｌａｓｔｉｃｔｈｅｏｒｅｔｉｃａｌｒｅｓｅａｒｃｈｅｓｏｗｉｎｇｔｏｉｔｓｅｘ ｔｒａｏｒｄｉｎａｒｙｓｕｐｅｒｐｌａ…     

稀土元素添加剂在泡沫铝合金制备中的应用

用稀土添加剂制取高强度稀土铝合金，相对抗拉强度σb相：1．07～1．32；延伸率δ：3．0％～7．5％；常压下添加合金增粘剂发泡剂后制得稀土泡沫合金，气孔率η：12．8％～33．5％。     

Investigation of Formation and Inhibition Mechanism of Cerium Conversion Films on Al 2024 Alloy

To study the mechanism of formation and inhibition of Ce conversion films on A1 2024-T3 alloy, scanning microreference electrode technique (SMRE) is used to probe the potential map on A1 2024-T3 in CeC13 solution, the localized corrosion of A1 alloy decreases with immersion time and disappears finally, which results from the competition of Cl^- aggression and Ce^3 inhibition on alloy surface. The results of X-ray photoelectron spectroscopy (XPS) indicate that the Ce conversion films consist of Al2O3, CeO2 and Ce2O3 (Ce(OH)3), and CeO2/Ce2O3 ratio decreases with the immersion time. When a critical pH for Ce(OH)3 formation was reached, Ce(OH)3 will precipitate on the micro cathodic area on alloy surface. Consequently, H2O2, the product of the catholic reaction will oxidize a part of Ce(OH)3 to CeO2, which appears a better corrosion resistance for Al alloys.     

含稀土金属铈的锌冲压性能和耐蚀性能

研究了添加2#工业铈的1#工业用的金属锌板和不添加2#铈的1#工业纯锌板的冲压性能、耐蚀性及铸态硬度．试样经轧制和在室温条件下作拉力试验，取得常规条件下的屈强比σ0.2／σb、加工硬化指数n、塑性应变比γ、均匀延伸率εb和各向异性值△γ，找出稀土金属铈含量对1#金属锌的冲压性能、耐蚀性能的影响和铸造状态的硬度变化．     

电弧喷涂Zn-Al-Mg-La-Ce涂层的耐腐蚀性能

采用电弧喷涂法制备Zn-Al-Mg-La-Ce涂层,通过盐雾试验对涂层进行腐蚀,利用能谱分析、X射线衍射分析、扫描电镜观察、极化曲线以及电化学阻抗谱等手段对腐蚀前后的Zn-Al-Mg-La-Ce涂层进行了研究.结果表明:实验制备的Zn-Al-Mg-La-Ce涂层具有较好的自封闭效果,组织致密,在腐蚀过程中表面的微观孔隙能够被自身的腐蚀产物有效堵塞,涂层表面形成的致密腐蚀产物层能够阻止腐蚀的进一步发生.因此,Zn-Al-Mg-La-Ce涂层具有优异的耐蚀性能.     

Effect of Annealing on Rare Earth Based Hydrogen Storage Alloys

Rare earth-based hydrogen storage alloy used as negative electrode materials for nickel-metal hydride (Ni-MH) batteries are used commercially.The effect of annealing treatment with different annealing temperature and time on the MLNi3.68 Co0.78 Mn0.35 Al0.27 and MMNi3.55 Co0.75 Mn0.40 Al0.30 alloys were investigated.The crystal microstructure,pressure-composition-isotherms (p-C-T) and electrochemical properties of alloys were examined by X-ray diffraction (XRD), automatic PCI monitoring system and electrical performance testing instruments.The optimum annealing treatment conditions of two kinds of alloys were determined.     

稀土厂废水的放射性及其净化技术探讨

基于稀土厂废水的放射性,吸取水质放射性污染净化原理与多种粘土矿物和土壤对稀土的吸附性,探讨稀土厂废水放射性的净化技术。建议稀土厂在现有废水处理的基础上,建吸附滤池,通过混合吸附剂对水中放射性元素的吸附,净化废水放射性,确保环境辐射安全性。     

Preparation and Corrosion Resistance of Rare Earth Ceramic Film on AZ91 Magnesium Alloy

With the purpose of improving corrosion resistance and solving environmental pollution caused by traditional protective technique, rare earth ceramic film on AZ91 magnesium alloy was prepared by dip coating process, and technical parameters of preparation were defmed. Microstructure and composition of the film were studied and corrosion resistance was evaluated as well. The results show that rare earth ceramic film is uniform,dense, with strong cohesion and intact coverage. The film is mainly made up of CeO2 and MgCeO3. The results of corrosion experiments approve that the film acts as a barrier to isolate the contact of the substrate with corrosion media and decreas corrosion rate. Polarization curve of the coated sample shiftes to positive potential obvito 2.7 × 104 Ω. These facts indicate that rare earth ceramic film could effectively improve corrosion resistance of AZ91 magnesium alloy.     

Influence of Cerium on Corrosion of AZ91 Magnesium Alloy

Effect of cerium addition on corrosion resistance of AZ91 magnesium alloy was investigated using the static weight loss and polarization curve method as well as metallographical observation. The results indicate that a small amount of cerium （0.2% - 0.8%） in AZ91 magnesium alloy can significantly reduce the corrosion rate, enhance the electrode voltage and lower corrosion current density in 3.5%NaCl aqueous solution, and AZ91-0.8% Ce alloy has better corrosion resistant performance. The reason for increasing corrosion resistance is attributed to the addition of Ce, refining the α-Mg grain, reducing the segregation of element Al, and improving the morphologies of β-Mg17 Al12 phases.     

Effect of Cerium on Mechanical Properties and Morphology of ZZn4-1 Alloy

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Influence of Rare Earth Elements on Microstructure and Mechanical Properties of Mg-Li Alloys

Mg-Li alloy , which is also called superlight al-loy ,has many advantages ,such as lowdensity ,highstiffness-to-weight ratio , superior strength-to-weightratio ,good deformation ability ,good damping ability ,and high energetic particle penetration resistance[1 ,2].These advantages provide promising applicationsintheaerospace , electronic industry , and military field[3].Mg-Li alloys ,such as LA141 , LA191 ,and LAZ933were developed and have been usedfor components insatellites and aircrafts…     

稀土钝化——金属防腐蚀表面处理新技术

稀土钝化处理是近年来国内外研究开发的一种金属表面无铬钝化处理新技术 ,具有无毒无污染和防腐蚀效果好的特点 ,可望成为传统铬酸盐钝化法的主要替代技术之一。本文对文献所报道的稀土钝化技术的工艺方法和成膜原理进行综述 ,并介绍了稀土转化膜在钢铁、铝、锌、镁、锡、铜等金属或合金上的防蚀作用效果及耐蚀机理。并对该技术的应用前景作了展望。     

Crystallization and Microstructure Evolution of Amorphous Al85 Y4 Nd4 Fe7 Alloy

A rapidly solidified Al85Y4Nd4Fe7(%, in nominal atomic fraction) alloy was prepared by melt spinning. Asquenched and as-annealed microstructures were studied by differential scanning calorimetry (DSC), X-ray diffraction(XRD), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). Fully amorphous structure could be obtained in the rapidly solidified Al85Y4Nd4Fe7 alloy ribbons. The temperature of first crystallization exceeds 300℃. Crystallization of as-annealed Al85Y4Nd4Fe7 alloy is shown to occur in two stages : ( 1 ) primary crystallization of α-Al; (2) formation of Al3Y, Al13Fe4 and unknown crystalline phases.     

Ce对Al4.5Cu合金流动性和热裂倾向的影响

研究加入稀土Ce对Al4.5Cu合金流动性、凝固收缩、微观组织和热裂倾向的影响。结果表明,适量稀土Ce的加入,降低金属液的黏度,提高合金流动性,减少金属在凝固过程中的收缩,抑制合金枝晶化的趋势,改善铸造合金的微观组织,净化合金,提高合金的导热率,明显地减少合金的热裂倾向。稀土Ce加入量为4%时,Al4.5Cu合金流动性最佳、凝固收缩量最小、合金晶粒组织细化圆整,同时其热裂倾向最小。     

Effect of Rare Earth Metals on Structure and Properties of Electroless Co-B Alloy Coating

The effect of rare earth metals cerium, lanthanum and yttrium on chemical composition, structure and properties of electroless Co-B alloy coating was studied. By plasma transmitting spectrograph, electron energy spectrometer, X-ray diffractometter, miero-hardometer and vibratory- sample magnetometer the chemical constitution,structure and properties of the alloy coatings were analyzed and inspected. The results show that with a tiny quantity of rare earth metal added into Co-B alloy coating, the content of boron is decreased in the alloy coatings, and the kinds of rare earth metal have enormous effect on the structure and properties of electroless Co-B alloy coating. At the same time electroless Co-B alloy with amorphous structure is transformed to electroless Co-B-RE alloy with microcrystalline or crystalline structure. In this way microhardness of the coatings is increased remarkably. Cerium and lanthanum would also increase the saturated magnetic intensity and decrease coercitive force of the coating. So soft magnetization of the coatings would be improved.