氯化物熔盐体系共电沉积法制备Al-Li-Gd合金的研究

在773K时,采用循环伏安法、方波伏安法和计时电位法研究了Gd(III)和Al(III)在LiCl-KCl-AlCl3-GdCl3熔盐体系中的电化学行为及共电沉积制备Al-Li-Gd合金,并借助XRD,SEM-EDS对所得合金进行表征.结果表明,Gd(III)在预先沉积的Al上欠电位沉积形成了两种Al-Gd金属间化合物,当电流密度超过-279.5 mA/cm2时,Al,Gd和Li能同时析出.通过调节熔盐中AlCl3的含量可以获得不同相的Al-Li-Gd合金.Al-Li-Gd合金含有Al2Gd和Al2Gd3,Gd在合金中分布不均匀,而Al的分布相对均匀.     

Electrochemical study on preparation of Mg-Li-Yb alloys in LiCl-KCl-KF-MgCl2-Yb2O3 melts

This paper presented a novel study on electrochemical codeposition of Mg-Li-Yb alloys in LiCl-KCl-KF-MgCl2-Yb2O3 melts on molybdenum. The factors of the current efficiency were investigated. Electrolysis temperature had great influence on current efficiency; the highest current efficiency was obtained when electrolysis temperature was about 660 oC. The content of Li in Mg-Li-Yb alloys increased with the high current densities. The optimal electrolytic temperature and cathodic current density were around 660 oC and 9.3 A/cm2, respectively. The chemical content, phases, morphology of the alloys and the distribution of the elements were analyzed by X-ray diffraction, scanning electron microscopy, inductively coupled plasma mass spectrometry, respectively. The intermetallic of Mg-Yb was mainly distributed in the grain boundary of the alloys, presented as reticulated structures, and refined the grains. The lithium and ytterbium contents in Mg-Li-Yb al-loys could be controlled by changing the concentration of MgCl2 and Yb2O3 and the electrolysis conditions.     

铝酸钠对镁-锂合金微弧氧化膜耐蚀性的影响

为了进一步提高镁-锂合金的理化性能,将不同质量浓度的铝酸钠添加到硅酸盐体系的电解液中,制备出镁-锂合金微弧氧化陶瓷膜。通过对膜层的表面形貌、组成及耐蚀性的研究,分析了铝酸钠的质量浓度对镁-锂合金微弧氧化膜的组成、厚度、结构及性能的影响。研究结果表明:与未添加铝酸钠的微弧氧化膜相比,加入铝酸钠后,微弧氧化膜表面单位面积内的微孔数量减少,孔径明显变小,且其耐蚀性大幅提高。     

LiCl-KCl-MgCl2-Gd2O3熔盐共电沉积制备Mg-Li-Gd合金

在823 K和973 K的条件下,采用恒电流密度共电沉积法在LiCl-KCI-MgCl2-Gd2O3熔盐体系中制备Mg-Li-Gd合金,并运用XRD、SEM、EDS和OM对所制备合金进行微观组织分析.结果表明:在开始的30 min内,主要是Mg和Gd的沉积,所得合金含96.53%Mg,3.20%Gd和0.27%Li(质量分数),然后Li迅速沉积.可以通过控制电解时间或改变Gd2O3的浓度调节Mg-Li-Gd合金的组成.XRD分析可知,在Mg-Li-Gd合金中存在Mg3Gd相和Mg2Gd相.从Gd元素的面扫描分析可知,Gd元素主要分布在Mg-Li-Gd合金的晶界处.Gd的添加增强了合金的抗腐蚀能力.     

Electrochemical formation of Mg-Li-Y alloys by co-deposition of magnesium, lithium and yttrium ions in molten chlorides

An electrochemical approach for the preparation of Mg-Li-Y alloys via co-reduction of Mg, Li, and Y on a molybdenum electrode in LiCl-KCl-MgCl2-YCl3 melts at 943 K was investigated. Cyclic voltammograms (CVs) illuminated that the underpotential deposition (UPD) of yttrium on pre-deposited magnesium led to the formation of a liquid Mg-Y alloy, and the succeeding underpotential deposition of lithium on pre-deposited Mg-Y led to the formation of a liquid Mg-Li-Y alloy. Chronopotentiometry measurements indicated that the order of electrode reactions was as follows: discharge of Mg(II) to Mg-metal, electroreduction of Y on the surface of Mg with formation of ε-Mg24+xY5 and after that the discharge of Li+ with the deposition of Mg-Li-Y alloys. X-ray diffraction (XRD) indicated that Mg-Li-Y alloys with different phases were formed via galvanostatic electrolysis. The microstructure of different phases of Mg-Li-Y alloys was characterized by optical microscope (OM) and scanning electron microscopy (SEM). The analysis results of inductively coupled plasma atomic emission spectrometer (ICP-AES) showed that the chemical compositions of Mg-Li-Y alloys corresponded with the phase structures of the XRD patterns, and the lithium and yttrium contents of Mg-Li-Y alloys depended on the concentrations of MgCl2 and YCl3 .     

熔盐电解制备四元Mg-Zn-Li-Ca合金(英文)

在LiCl-KCl-MgCl2-ZnCl2-CaCl2熔盐体系中,以钼为惰性电极,在温度为943K时,直接电解制备Mg-Zn-Li-Ca四元合金。循环伏安研究表明,在LiCl-KCl熔盐体系中,添加MgCl2、ZnCl2和CaCl2后,Li的析出电位明显正移。计时电位研究表明,当阴极电流密度等于或者更负于-1.55A/cm2时,Mg、Li/Zn和Ca能够实现四元沉积。X射线衍射研究表明,恒电流电解可以制备出由不同相组成的Mg-Zn-Li-Ca合金。采用金相显微镜和电子扫描显微镜对合金样品进行表征。能谱分析结果表明,Mg元素和Ca元素在合金中分布均匀,而Zn元素主要分布在基体的边缘。     

《水处理与膜分离技术》课程案例库教学设计与实践

案例教学法是一种通过丰富教学手段、理论联系实际、加强师生互动等方式来提升专业学位研究生课程教学质量的方法。基于材料与化工专业学位研究生课程“水处理与膜分离技术”案例库的建设实践,讲述案例教学的过程：确定主题→建立案例编写小组→收集案例、整理资料→编写案例→案例内容展示与课程讨论→总结反思。在案例内容中融入最新研究进展与课程思政内容,可促进学生学习兴趣并进一步提升专业学位研究生的教学质量。     

Electrochemical behaviour of erbium and preparation of Mg-Li-Er alloys by codeposition

The electrodeposition of erbium on molybdenum electrodes and the formation of Mg-Li-Er alloys were investigated in LiCl-KCl molten salts. At a molybdenum electrode, the electroreduction of Er (III) proceeded in a one-step process involving three electrons. The diffu-sion coefficient of erbium ions in the melts was determined by cyclic voltammetry, chronopotentiometry and chronoamperometry respectively. Cyclic voltammograms (CVs) showed that the underpotential deposition (UPD) of lithium on pre-deposited Mg-Er alloy led to the formation of a Mg-Li-Er alloy. X-ray diffraction (XRD) indicated that Er5Mg24 phase was formed via potentiostatic electrolysis. Scanning electron microscopy (SEM) showed that Er atoms mainly concentrated at the grain boundaries while Mg element evenly located in the alloy.     

氯化物熔盐体系共电沉积法制备Mg-Li-Gd合金的研究

在LiCl-KCl-MgCl2-Gd2O3熔盐体系中采用电化学共沉积法制备Mg-Li-Gd合金,借助循环伏安和计时电位技术对熔盐电化学行为进行探讨,并运用XRD,SEM,EDS和OM对所得合金进行测试.研究结果表明,Gd2O3在LiCl-KCl熔盐体系中几乎不溶,而在LiCl-KCl-MgCl2熔盐中有一定的溶解度,而...     

Pb(Ⅱ)在LiCl-KCl-MgCl_2-PbCl_2熔盐体系中的电化学行为(英文)

在LiCl-KCl-PbCl2-MgCl2熔盐体系中借助循环伏安和计时电位技术对Pb(Ⅱ)的电化学行为以及Pb、Mg、Li的共沉积过程进行探讨,用不同的方法测算得到铅离子在熔盐中的扩散系数。循环伏安和计时电位的研究结果均表明,Li在先析出的Pb上发生欠电位沉积,生成液态的Li-Pb合金,而在熔盐中加入MgCl2后,会有相应的Mg-Li-Pb合金生成。用恒电流密度(6.21A/cm2)电解2h制备Mg-Li-Pb合金,并运用XRD对所得合金进行分析测试。结果表明,在Mg-Li-Pb合金中存在β-Li、PbLi3、Mg2Pb等合金相,并可以通过控制熔盐中PbCl2和MgCl2的浓度来改变合金相的组成。