Analysis of Coating Microstructure of Hot-Dip Aluminum of Deformed Low-Carbon Steel Containing Rare Earth

The coating microstructure of hot-dip aluminum (HDA) of deformed low-carbon steel containing RE was analyzed by metallography microscopy, TEM and XRD, and the forming mechanism was also discussed. The results show that, the Fe_2Al_5 phase, on whose subcrystal boundaries, Al particles with the size of 7～30 μm existing on parallel linear are, grows a strong orientation. And the spread activation energy of Al is 155.22 kJ·mol -1. In addition, the effects of deformation on coating microstructure of hot-dip aluminum and the function of RE were preliminarily analyzed.

Effects of Copper-Zinc Alloy Doped with Rare Earth Elements on Crystal of Calcium Carbonate

A copper-zinc alloy doped with rare earth elements was prepared and the mechanism was demonstrated in a simulating boiler and circulating cooling water with rigidity 1 mmol·L-1. The polar curve and scale inhibiting ability of the alloy was tested by a corrosion measurement system and a scale inhibition evaluation system, respectively. Scale samples were characterized with SEM and XRD. It is found that the transfer of cations could be promoted by doping with proper rare earth elements, and the corrosion potentials descend by 25～126 mV. The results indicated that the copper-zinc alloy doped with rare earth elements has higher scale inhibiting ability of CaCO3. The growth of calcite was affected by zinc ions dissolved because of primary battery reaction, and the transition of calcium carbonate from aragonite to calcite was hampered resulting in the proportion of aragonite to calcite is changed from 1.7∶1 to 2.7∶1.

Effect of Rare Earth on the Corrosion-Resisting Performance of Zinc-Based Alloy Coatings

The corrosion behavior of coatings of pure zinc and Zn-Al,Zn-Al-RE alloys in NaCl solu- tions was studied by salt-spray experiments,even corrosion experiments and electrochemical measurements of bi-directional polarization curves and a.c.impedance in weak polarization region consistent regularities were obtained by these different methods,viz.,the corrosion resistance of Zn could be enhanced by alloying it with Al,and particularly with Al-RE.The causes of enhancement of corrosion resistance by RE were also discussed.

Effect of Rare Earth on theFormation of Liquid ZincCorrosion ResistantChromium-carbide Layer

The effect of rareearth reducing agent on the thickness of layer and properties of bathduring the forming process of liquidzinc corrosion resistant chromiumcarbide layer through the thermalreaction deposition and diffusionmethod was studied. The resultsshow that the addition of 8%RE-SiFe-Mg can make the borax systemwith 15% Cr2O3 have better chromium-carbide layer-formation abilityand excellent technical propertiesthan those of Al or Si at 950 ℃.

Rare Earth-Boronizing and Its Applications

The thickness, brittleness, boron content and morphology of RE boronized layer were investigated. The results show that the service life of the boronized layer in molten zinc can be increased by adding RE element. The thermocouple and sink roll sleeve made of this material can be used for more than half a year.

稀土元素对桥梁缆索用热浸镀Zn-10Al镀层钢丝耐蚀性能的影响

通过双镀法制备Zn-10Al-xRE(x=0.05,0.08,0.11,0.14,0.17)五种热浸镀锌铝镀层,并利用中性加速盐雾试验、电化学实验及扫描电子显微镜(SEM)分析其腐蚀形貌及耐蚀性能。结果表明,五种镀层在中性加速盐雾试验下,可保证基体在120d以内不被腐蚀,而纯锌镀层在30d时已经出现红锈,证明Zn-10Al-xRE的耐蚀性能可达到纯锌镀层4~5倍。Zn-10Al-xRE镀层钢丝的耐蚀性能随稀土含量的上升先升高再降低,添加0.08%RE的Zn-10Al镀层耐蚀性最好。用SEM对120d盐雾试验下的镀层钢丝进行观察,可以看出纯锌镀层的腐蚀产物较为疏松,Zn-10Al-xRE的腐蚀产物较为致密,Zn-10Al-xRE中腐蚀产物大约分为韧窝状、球状及针片状,耐蚀性能最好的Zn-10Al-0.08RE镀层中含有大量韧窝状腐蚀产物。

滇西百济锑铅锌多金属矿化点黄铁矿微量元素和稀土元素地球化学

利用百济锑铅锌多金属矿化点早期矿化阶段的黄铁矿稀土元素和微量元素组成,推演成矿流体性质和成矿类型.黄铁矿LREE富集、HFSE亏损、变化的Y/Ho、Nb/Ta和Zr/Hf特征,指示该阶段的成矿流体主要是富Cl的流体,并且存在少量富F的流体混入.弱的正Eu异常和弱的负Ce异常特征,指示该阶段的成矿流体属于弱氧化性流体.根据黄铁矿样品总体上具有较高的Co含量(209×10~(-6)~7 610×10~(-6),均值为2 041×10~(-6))、Ni含量(109×10~(-6)~2 550×10~(-6),均值为746×10~(-6)),Co/Ni的变化范围介于0.86~6.83(均值为2.82)之间,推测百济矿化点早阶段形成的黄铁矿-辉钼矿-石英矿物组合是岩浆热液和浅成低温热液共同作用的产物.该研究为完善区域成矿作用提供了依据.

稀土掺杂氧化锌的制备进展

氧化锌是一种常见的宽禁带半导体光触媒,广泛用于光催化应用之中,为提高其光催化活性,通常采用稀土掺杂等方式,改变其载流子浓度与能带结构,同时利用稀土元素的4f-4f跃迁,对氧化锌的光学性能进行调控。因稀土掺杂氧化锌的制备简便、成本低廉且光催化性能优异,使其成为光催化领域的研究热点。文中主要综述了稀土掺杂氧化锌材料的制备方法,并给出了不同制备方法所得材料的实验结果,以期为后续该材料的进一步应用研究提供参考与借鉴。

重庆酉阳—贵州沿河地区铅锌及萤石矿床重晶石微量元素特征及指示意义

重庆酉阳—贵州沿河地区发育众多中—低温热液型铅锌矿及萤石—重晶石矿,两类矿床之间的成因联系还需进一步研究。在野外地质调查的基础上,对两类矿床共生的重晶石单矿物开展微量、稀土元素研究。结果表明,各重晶石样品具有相似的微量、稀土元素组成特征,均相对亏损Th、Nb、Nd、Sm、Y等元素,相对富集Rb、U、Sr、Zr、Hf、Lu等元素,Eu、Ce正异常显著,稀土元素配分型式为轻稀土元素相对富集的右倾型。认为区内铅锌矿及萤石—重晶石矿在成矿流体来源上一致或具有相似的成矿物质源区,可能是在同一构造运动时期形成的有亲缘关系的成矿系列;区内铅锌矿及萤石—重晶石矿的赋矿围岩中Pb、Zn、F、Ba等元素含量较低,其成矿物质可能主要来源于下伏牛蹄塘组。

Toxic Effects of Lanthanum, Cerium, Chromium and Zinc on Potamogeton Malaianus

The toxic effects of rare earth elements such as lanthanum, cerium and heavy metal elements such as chromium, zinc on Potamogeton malaianus Miq. were studied. The results show that the contents of chlorophyll and soluble protein increase to a certain degree and then decrease under La3+ Ce3+ Zn2+ stress, while there is a constantly dropping tendency under Cr6+ stress. The four ions have different effects on protective enzyme systems of Potamogeton malaianus. They can induce rises of the activities of catalase (CAT) and peroxides (POD) at lower concentration, however, with the increase of ions concentration, the activities decline. The change of SOD activity is exactly opposite to that of CAT and POD activity. It falls at first and rises later. An increasing tendency of MDA content appears with the increasing concentration. The toxicities of La3+, Zn2+, Ce3+ and Cr6+ become more serious in the order. The lethal concentration of Cr6+ to Potamogeton malaianus ranges from 0.5 to I mg(-1) that of Ce3+ and Zn2+ ranges from 3 to 5 mg(-1) and that of La3+ ranges from 7 to 10 mg(.)L(-1). The toxic mechanism of La3 + and Ce3+ is similar to that of Cr6+ and Zn2+.

Energy transfer from Ce^(3+) to Tb^(3+) and Eu^(3+) in zinc phosphate glasses

Ce3+,Eu3+ and Tb3+ singly doped and Ce3+/Eu3+ and Ce3+/Tb3+ co-doped zinc phosphate glasses were prepared by sintering P2O5,ZnO,Ce2(C2O4)3·10H2O and Eu2O3/Tb4O7 mixtures at 1200 °C in the air for 2 h and then annealing at 450 °C for 10 h.The obtained glasses were homogeneous and transparent.The glasses without Ce3+ were colorless and those with Ce3+ showed slightly yellow.The singly doped glasses showed strong emissions and excitations from doped trivalent rare earth ions.Strong energy transfer from Ce3+ to...

Corrosion Inhibition Synergism between Lanthanum(Ⅲ) Ion and 8-Hydroxyquinoline for Zinc in Hydrochloric Acid

The effects of La 3+ ion and chelate reagent 8 hydroxyquinoline on the corrosion rate of zinc in hydrochloric acid were investigated by using weight loss method and electrochemical method. It is found that in a specific concentration range of La 3+ ion and 8 hydroxyquinoline, the obvious corrosion inhibition synergism is obtained. The mechanism of corrosion inhibition synergism was discussed on basis of adsorption theory.

Photoluminescence and thermoluminescence properties of dysprosium doped zinc metaborate phosphors

Polycrystalline powder samples of dysprosium doped Zn（BO2）2 phosphors were prepared by solid state reaction in air at high temperature and characterized by X-ray powder diffraction. The IR, Photoluminescence （PL）, diffuse reflectance and three-dimensional （3D） thermoluminescence （TL） emission spectrum after 60^Co gamma ray irradiation were investigated. The characteristic 3D TL emission bands at about 425, 481 and 573 um with a main emission band of around 573 um were attributed to the host emission, 4^F9/2→6H15/2 and F9/2→6^H13/2 f-f transitions of Dy^3＋ ions. No emission from Dy^2＋ ions was observed in the measurement wavelength range. The TL-dose response of the Zn（BO2）2：Dy polycrystalline powder sample to gamma ray radiation in the range from 1 to 100 Gy at clinical dose levels was almost linear. The experimental results showed that Zn（BO2）2：Dy had potential use as the materials of gamma-ray thermoluminescence dosimeter （TLD） for clinical dosimetry.

Effect of Y(OH)_3 microparticles on the electrochemical performance of alkaline zinc electrodes

This work focused on the zinc powder coated with Y(OH)3 microparticles by means of ultrasonic immersion for performance improvement of zinc electrodes in alkaline battery systems.Scanning electron microscopy and other characterization techniques were applied to examine the influence of the ultrasonic power on the sonochemical growth of Y(OH)3 microparticles in direct contact with zinc powder.Electrochemical properties of zinc electrodes containing Y(OH)3 microparticles were discussed through the measurement...

Chemical Conversion Film of Mischmetal on Zinc Deposit

A conversion film was obtained on zinc deposit by immersing zinc coated specimens in a mischmetal salt solution. Several factors affecting the anticorrosive efficiency of the conversion film were studied. The suitable technological conditions were established. The composition and the thickness of the conversion film were determined by Auger electron spectroscopy(AES).

Effect of Yttrium on Aging Resistance of Zinc Alloy ZA-27

By metalloscopy,scanning electron microscope,X-ray diffraction,electron probe,salt water erosion and hot steam erosion,the microstructures and the aging resistance of zinc alloy ZA-27 with different contents of yttrium were studied. The results show that with optimum addition of yttrium in the alloy ZA-27 the fine YAl_3 phase forms. The fine YAl_3 granules can act as the condensation nuclei of α phase and the number of the α phase′s nuclei increases greatly and the growth of the nuclei comes in for restrict during the crystallization and the alloy′s grains become fine and the segregation reduces. In addition,yttrium also combines with zinc and the fine dispersion Y-Zn phase forms which improves grain boundary conditions and the alloy′s aging resistance. But when the content of yttrium is overmuch some YAl_3 granules grow to be lumpy,so the fine and close texture of the alloy′s boundaries is damaged and the proportion of the interface among the phases increase which brings a decline in the alloy′s resistance to corrosion.

Spectral Properties and Sensitization of Ce^(3+) and Eu^(2+) Codoped Calcium Zinc Chlorosilicate

The Ce^3+ and Eu^2+ ions codoped calcium zinc chlorosilicate Ca_8Zn(SiO_4)_4Cl_2 phosphors have been synthesized for the first time. The diffuse reflection, excitation and emission spectra of Ca_8Zn(SiO_4)_4Cl_2∶Ce^3+, Eu^2+ have been measured at room temperature. The luminescence sensitizaiton of Eu^2+ by Ce^3+ inCa_8Zn(SiO_4)_4Cl_2∶Ce^3+, Eu^2+ has been expounded under the excitation of ultraviolet light and the efficient nonradiative energy transfer from Ce^3+ to Eu^2+ in this system is confirmed.

大规格1960K级AB类热镀锌-5%铝稀土合金钢丝研制

大规格1 960K级钢丝要求具有高韧性、高尺寸精度、满足AB级热镀锌-5%铝稀土合金面质量。优化钢丝表面处理和热处理工艺,钢丝热镀锌-5%铝稀土合金层工艺,确定合理的生产工艺流程,开发出适合高碳钢高强度大规格镀锌-5%铝稀土合金钢丝拉拔的专用拉丝模,优选出适合镀锌-5%铝稀土合金层钢丝拉拔的钙系DYH-38拉丝粉,确定了拉拔时合理的部分压缩率7%~16%,生产Ф2.63 mm 1 960K级AB类热镀锌-5%铝稀土合金层中镀后拉拔钢丝时车速可稳定在330 m/min,生产的钢丝力学性能超过了标准要求,镀层面质量符合AB类锌层要求。

稀土元素对固体渗硼层的改性作用

通过研究渗硼层厚度、脆性、表面含硼量、表面形貌的变化及耐锌液腐蚀的性能，充分证实了稀土元素对改善渗硼组织有明显作用。结果表明，改性渗硼组织的耐锌腐蚀寿命大幅度提高，将其制成测温热电偶用于工业生产，耐锌液腐蚀寿命达半年之久，为解决热镀锌设备的腐蚀问题提供了一种有效方法。

陕西几类重要铅锌矿床的矿物微量元素和稀土元素特征

文章将陕西铅锌矿分为海底喷气沉积型(即SEDEX型)、与海底喷气沉积-改造作用有关的类SEDEX型和MVT型3类。对马元(MVT型)、南沙沟和江坡(类SEDEX型)、铅硐山和二里河(SEDEX型)铅锌矿床中的闪锌矿等矿物进行的微量元素和稀土元素测定结果表明,3类矿床各具特点:马元铅锌矿床闪锌矿的Co、Ni、Th、Y含量较低,而Mo、Cs、Sr、Ba、Tl含量较高;南沙沟和江坡铅锌矿床闪锌矿的Sn、Sb、W含量较低,而Mn、Y、Zr、In含量较高;铅硐山和二里河铅锌矿床闪锌矿的Li、Zr、Cs、Ba含量较低,而W含量较高;在闪锌矿Li-Cs、Zr-In、W-Sn、ΣREE-δEu、δEu-δCe散点图上,5个矿床的投点按上述3类分别集中。但铅硐山和二里河铅锌矿床与南沙沟和江坡铅锌矿床具有更多的相似性,而与马元铅锌矿床差异较大:在闪锌矿Sr-Ba、Co-Ni、Th-Y、Mo-Tl散点图上,马元的投点集中于一处,而其他4个矿床的投点集中于另一处;马元闪锌矿具有十分明显的铕正异常,而南沙沟、江坡、铅硐山和二里河闪锌矿铕异常不明显,或具有负铕异常;5元素矿床闪锌矿稀土元素配分曲线均为轻稀土元素稍富集的右倾型,但马元的稀土元素总量明显低于其他4个矿床。