Electrochemical Investigation on the Preparation of Erbium－Cobalt Alloy by Electrolysis

ＥｌｅｃｔｒｏｃｈｅｍｉｃａｌＩｎｖｅｓｔｉｇａｔｉｏｎｏｎｔｈｅＰｒｅｐａｒａｔｉｏｎｏｆＥｒｂｉｕｍ－ＣｏｂａｌｔＡｌｌｏｙｂｙＥｌｅｃｔｒｏｌｙｓｉｓ￥ＬｉｕＧｕａｎｋｕｎ（刘冠昆），ＨｏｎｇＨｕｉｃｈａｎ（洪惠婵），ＹａｎｇＱｉｑｉｎ（杨绮琴...     

Electrochemical behavior of dysprosium(III) in eutectic LiF-DyF3 at tungsten and copper electrodes

Electrochemical behavior of dysprosium (Dy) ions in LiF-DyF₃ (24 mol%) was investigated by cyclic voltammetry, chronoamperometry and chronopotentiometry. Dy‐Cu alloy samples were prepared by constant-potential electrolysis in LiF-DyF₃ (24 mol%) at the Cu electrode. The Cu₅Dy and Cu phases were characterized by an X-ray diffractometer and a scanning electron microscope equipped with an energy dispersive spectrometer. The results show that the reduction of Dy(III) ions in a LiF-DyF₃ (24 mol%) molten salt system is found to be a quasi-reversible diffusion-controlled process which occurs via a one-step reaction involving the transfer of three electrons. The electro-crystallization processes of the Dy metal at the W electrode and the mode of nucleation confirm that progressive nucleation is dominant at high concentrations of Dy ions in the LiF-DyF₃ salt. At lower concentrations, the instantaneous nucleation of Dy with three-dimensional growth of the nuclei is dominant.     

Electrochemical behavior of Dy(III) on bismuth film electrode in eutectic LiCl-KCl melts

An electrochemical study of dysprosium (III) on Bi film electrode was carried out in eutectic LiCl-KCl melts by transient and steady state electrochemical techniques. The results of transient electrochemical techniques showed that the reduction of Dy (III) appears at a more positive value than the one detected on W electrode owing to the formation of Bi-Dy intermetallic compounds through electrochemical deposition of Dy on bismuth film electrode. The thermodynamic properties of the formation for Dy-Bi intermetallics were estimated by a steady state electrochemical method in a temperature range of 713–803 K. Furthermore, the electrochemical preparation of Bi-Dy alloys was conducted by galvanostatic electrolysis at different current intensities. The Bi-Dy alloys, characterized by scanning electron microscopy equipped with energy dispersive spectrometry and X-ray diffraction, are comprised of DyBi_3/5 and DyBi phases.     

Studies on the Preparation of Lanthanum-Copper Alloy by Molten Salt Electrolysis

The electrochemical behaviour of copper electrode in molten NaCl-KCl-LaCl_3 has been investigated.TheLa-Cu alloy is formed at first and then the metallic lanthanum is deposited when the La~(3 )is reduced on thecopper electrode.The technological conditions of preparing La-Cu alloy by consumable cathode have been dis-cussed.The La-Cu alloy contained lanthanum over 90wt% was obtained.The composition of alloy was LaCu_2and La.The current efficiency was 85% and the recovery of lanthanum was near 90%.     

Molten salt synthesis of neodynium oxyfluoride in various fluoride media with different fluoride ion activities

Neodymium oxyfluoride has received much attention in the fields of anionic solid electrolytes, luminescent, catalytic and magnetic materials because of its structure combined advantages of rare-earth cations with F^– and O^2– anions. In this work, neodynium oxyfluoride was synthesized by the reaction between neodymium oxide and four fluoride media with different fluoride ion activities. The synthesis processes in molten LiF–CaF₂–NdF₃, LiF–NdF₃, NaF–CaF₂-NdF₃ and NaF–KF–NdF₃ are observed in situ by a confocal scanning laser microscope. The expansion of neodymium oxide particle is observed in the LiF–CaF₂–NdF₃, LiF–NdF₃, and NaF–KF–NdF₃ melts, and the growth of needle crystals on neodymium oxide particle is clearly observed in molten NaF–CaF₂–NdF₃. Based on scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) analyses of products, neodynium oxyfluoride was successfully synthesized in the four fluoride media. The neodynium oxyfluoride generated in the LiF–CaF₂–NdF₃, LiF–NdF₃, and NaF–KF–NdF₃ melts is a tetragonal structure. However, in molten NaF–CaF₂–NdF₃, neodynium oxyfluoride with a rhombohedral structure is formed. It is suggested that the substitution of Na(I) and Ca(II) for Nd(III) can transform NdOF from tetragonal structure to rhombohedral structure. The growth rate of needle crystals generated in molten NaF–CaF₂–NdF₃ was calculated based on the result of a confocal scanning laser microscope, and it is found that the reaction kinetics of crystal formation is zero-order reaction. The effect of fluoride media on the structure and morphology of formed NdOF were evaluated by XRD, X-ray photoelectron spectroscopy (XPS) and SEM. The neodymium oxyfluoride prepared in the fluoride media with high fluoride ion activity has low binding energy of F 1s. The ratio of adsorbed oxygen to lattice oxygen for neodymium oxyfluoride prepared in molten LiF-NdF₃ is larger than those in the other three fluoride media, so it can have better catalytic performance.     

Behavior of Cerium Addition in the Binary Fe-28Al Alloy

ｎｔｅｒｍｅｔａｌｉｃｓｂａｓｅｄｏｎＦｅ３Ａｌａｆｏｒｄｅｘｃｅｌｅｎｔｏｘｉｄａｔｉｏｎｒｅｓｉｓｔａｎｃｅｐｒｏｐｅｒｔｉｅｓａｔｒｅｌａｔｉｖｅｌｙｌｏｗｃｏｓｔａｎｄｍａｔｅｒｉａｌｓｄｅｎｓｉｔｙ，ｍａｋｉｎｇｔｈｅｍｃａｎｄｉｄａｔｅｓ...     

氯化钕熔盐电解制取钕铁中间合金

本文简要评述了制取Nd及富Nd合金的方法,分析讨论了用消耗性Fe阴极电解NdCl_3-KCl熔盐制取Nd-Fe合金的原理及选择技术条件的原则。实验室电解试验获得了含Fe仅13％的优质Nd-Fe合金,69％的合金电流效率(按纯Nd计为60％),Nd直收率大于90％。试验结果表明,本法是技术上合理、经济上有利的制取Nd-Fe合金的简便有效方法。     

Molten salt synthesis of Z-scheme CeO2/C3N4 photocatalysts with excellent properties for removal of organic pollutants: Characterization,kinetics and mechanisms

In this work,we firstly synthesized a CeO₂/C₃N₄ photocatalyst with Z-scheme heterojunction by a facile LiC-KCI molten salt method.The synthesized catalyst has an excellent quality for removing organic pollution of dyes and antibiotics in wastewater.As an example,the CeCN-1:5 prepared with a mass ratio of Ce₂(CO₃)₃·xH₂O:C₃H₃N₆=1:5 exhibits a methylene blue(MB) removal capacity of 100%with...     

Effects of Alloying Elements on Microstructure and Magnetic Anisotropy of the HDDR Powder ofNd-Fe-B Alloy

ＥｆｅｃｔｓｏｆＡｌｏｙｉｎｇＥｌｅｍｅｎｔｓｏｎＭｉｃｒｏｓｔｒｕｃｔｕｒｅａｎｄＭａｇｎｅｔｉｃＡｎｉｓｏｔｒｏｐｙｏｆｔｈｅＨＤＤＲＰｏｗｄｅｒｏｆＮｄＦｅＢＡｌｏｙＧａｏＪｉａｎｒｏｎｇ（高建荣），ＳｏｎｇＸｉａｏｐｉｎｇ（宋晓平），Ｗａ...     

Er-Fe-Ni合金膜在二甲基亚砜中电化学制备的研究

利用循环伏安法和恒电位电解法研究了室温条件下在LiClO4-DMSO(二甲基亚砜)体系中Er-Fe-Ni合金膜的电化学制备，实验结果表明：在0．1mol．L^-1ErCl3-0．1mol.L^-1FeCl2-0．1mol．L^-1 NiCl2-0．1mol.L^-1LiClO4-DMSO体系中，控制电位在-2.00V--2．60V范围内进行恒电位电解，可得到表面均匀、附着力强、有金属光泽的黑色非晶态Er-Fe-Ni合金膜，其中稀土Er的质量百分含量可达31．39％～41．63％。     

熔盐电解直接制备钛镍合金的研究

研究了利用熔盐电解法从金属氧化物中直接电解制备钛镍合金的可行性。在熔融CaCl2体系中,以二氧化钛和氧化镍的混合物为阴极,石墨为阳极,在电解温度900～1000℃,槽电压2.6～3.1V条件下进行电解,采用SEM,EDS,XRD等方法对电解还原产物进行了分析,结果表明二氧化钛和氧化镍被电解还原为钛镍合金,组成符合设计配比,并且沿直径方向合金成分均匀。     

Microstructure Variation of Nd_(15)Fe_(77)B_(8) Alloy in Hydrogenation-Disproportionation-Desorption-Recombination Process

ＭｉｃｒｏｓｔｒｕｃｔｕｒｅＶａｒｉａｔｉｏｎｏｆＮｄ１５Ｆｅ７７Ｂ８ＡｌｏｙｉｎＨｙｄｒｏｇｅｎａｔｉｏｎＤｉｓｐｒｏｐｏｒｔｉｏｎａｔｉｏｎＤｅｓｏｒｐｔｉｏｎＲｅｃｏｍｂｉｎａｔｉｏｎＰｒｏｃｅｓＬｉＬｏｎｇ（李隆），ＬｕｏＫａｎｃｈａ...     

Surface modification of （Tb0.3Dy0.7）Fe1.95 alloy by ion nitriding process

Effect of ion nitriding modification on surface hardness, corrosion resistance and magnetostriction of (Tb0.3Dy0.7)Fe1.95 alloy was investigated. Results demonstrated that a 100-200 nm thick nitrided layer was formed on the sample surface by ion nitriding treatment, which improved obviously surface hardness, wear, and corrosion resistance properties of (Tb0.3Dy0.7)Fe1.95 alloys. The surface hardness was increased from HV587 to HV622 after ion nitriding at 650 K for 6 h. Furthermore, ion nitriding treatment had almost no influence on mag-netostrictive performance as the nitrided layer was quite thin and the treatment temperature was not too high. The results might provide us a new approach for surface modification of (Tb0.3Dy0.7)Fe1.95 alloy.     

Electrochemical Studies of Effect of Eu~(3 ) on Adenosine-5′-Diphosphate at Mercury Electrode

Ｎｕｃｌｅｉｃａｃｉｄｓｐｌａｙｉｍｐｏｒｔａｎｔｒｏｌｅｓｉｎｔｈｅｍｏｌｅｃｕｌａｒｂｉｏｌｏｇｙ．Ｔｈｅｅｎｏｒｍｏｕｓｇｒｏｗｔｈｉｎｔｈｅｎｕｃｌｅｉｃａｃｉｄｒｅｓｅａｒｃｈｈａｓｒｅｓｕｌｔｅｄｉｎａｎｅｅｄｆｏｒｍｅｔｈｏｄｓｓｕｉｔ...     

Effect of Addition of Al on Crystal Structure Microtexture and Magnetostriction Coefficient in Tb0.3 Dy0.7 Fe1.95 Alloy

The effect of addition of A1 on crystal structure microtexture and magnetostrictioncoefficient in Tb0.3Dy0.7Fe1.95 alloy were studied.The results show that addition of A1 does not change crystal structure of alloy and the precipitates increase in the microtexture as addition of A1 increases.At a certain magnetic field, magnetostriction coefficient decreased as addition of Al increased.     

钕铁在NdCl_3-KCl熔盐中溶解行为的研究

在用电化学方法研究了钕在NdCl_3熔盐中溶解度和溶解机理之后,本文用重差法和最大气泡压力法测定了钕和钕铁合金在NdCl_3-KCl熔盐中的溶解损失,熔盐表面张力与添加剂的关系,证实了钕铁合金的电化学和化学溶解机理:钕在熔盐中溶解损失是影响电流效率的主要因素。     

熔盐电解SiO2/TiO2制备硅钛合金的研究

采用熔盐电解法通过直接电解SiO2、TiO2混合物料来制备硅钛合金。热力学计算结果表明,在700℃下,SiO2和TiO2的理论分解电压分别为1.28V和1.37V,生成的单质硅和钛在高温下能够自发进行合金化反应,生成硅钛系列合金,且容易倾向于生成稳定合金相TiSi2合金。研究表明,以摩尔比50∶1的SiO2/TiO2混合物料为原料,在等摩尔比的CaCl2-NaCl混合熔盐中,在700℃、2.4V槽电压下,经过5h电解后,制备得到TiSi2/Si合金,微观形貌为粒径0.2~2.5μm的多孔颗粒堆积,单质硅颗粒覆盖在TiSi2合金颗粒表面。     

Effects of Magnetic Heat Treatment on Magnetostiction Properties of Tb0.3 Dy0.7 Fe1.95 Alloy

The effects of magnetic heat treatment on magnetostriction properties of Tb0.3Dy0.7Fe1.95 alloy were investigated.The directionally solidified alloy was heated to various temperatures near Curie temperature TC in vacuum, kept for a certain time under the application of magnetic field and then cooled to room temperature.The magnetostriction coefficient was measured by a resistance strain gage.The crystal structure was analyzed by X-ray diffraction (XRD).The experimental results show that the magnetostriction coefficient obviously increases and the grains orientations along the axis changed somewhat as the field of 1 T vertical to axis of the rod-shaped specimen is applied for 5 min at the heating temperature slightly lower than TC.     

Study on Structural Stability of RE/Fe Multilayers

ＳｔｕｄｙｏｎＳｔｒｕｃｔｕｒａｌＳｔａｂｉｌｉｔｙｏｆＲＥ／ＦｅＭｕｌｔｉｌａｙｅｒｓＬｉＳｈｅｎｇｌｉ（李胜利），ＷａｎｇＣｈａｎｇｚｈｅｎｇ（王长征），ＢａｏＷｅｎｌｉａｎｇ（鲍文良）（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅ...     

Mechanism of RE on the Electrochemical Properties of Multicomponent Hydrogen Storage Alloys of RENi~5 Type

ＭｅｃｈａｎｉｓｍｏｆＲＥｏｎｔｈｅＥｌｅｃｔｒｏｃｈｅｍｉｃａｌＰｒｏｐｅｒｔｉｅｓｏｆＭｕｌｔｉｃｏｍｐｏｎｅｎｔＨｙｄｒｏｇｅｎＳｔｏｒａｇｅＡｌｏｙｓｏｆＲＥＮｉ５ＴｙｐｅＪｉａｎｇＪｉａｎｊｕｎ（江建军）（ＨｕａｚｈｏｎｇＵｎｉｖｅｒｓｉ...