材料期刊网

Preparation of ternary Mg-Li-Sn alloys from molten salt by electrolysis

Peng CAO , Milin ZHANG , Wei HAN , Yongde YAN , Lijun CHEN

金属学报(英文版)

Electrochemical behavior of Mg, Li and Sn on tungsten electrodes in LiCl-KCl-MgCl₂-SnCl₂ melts at 873 K was investigated. Cyclic voltammograms (CVs) showed that the underpotential deposition (UPD) of magnesium on pre--deposited tin leads to the formation of a Mg-Sn alloy, and the succeeding underpotential deposition of lithium on pre-deposited Mg-Sn alloy leads to the formation of a Mg-Li-Sn alloy. Chronopotentiometric measurements indicated that the codepositon of Mg, Li and Sn occurs at current densities more negative than -1.16 A·cm ^{- 2}. X-ray diffraction (XRD) indicated that Mg₂Sn phase is formed via galvanostatic electrolysis. The element Mg distributes homogeneously and Sn locates mainly on the grain boundaries in the Mg-Li-Sn alloy.

关键词: Mg-Li-Sn alloy , null , null , null

炭纤维层间化合物的制备及其膨化（英文）

新型炭材料

在浓硝酸溶液(13mol/dm3)中,通过恒电流电解,成功地进行了中间相沥青和聚丙烯腈基两种炭纤维(MPCF,PANCF)的硝酸插层.虽经水洗和干燥后有部分被分解成残余化合物,但从其层间距增至0.78nm左右这一现象证实已形成了层间化合物.经急剧加热至1000℃后,观察到了显著的形貌变化,单根纤维沿着纤轴被劈裂开,转变成一束微纤维.低结晶度PAN-CF经急热处理后,被观察到了这种膨化现象.对经2000℃左右处理的MPCF,在两个阶段,电解时CF的电势明显增加:1500℃处理的MPCF电解电势逐渐增加,而1150℃处理的MPCF,此值几无上升.

关键词: 层间化合物 , 电解 , 膨化炭纤维 , 中间相沥青基炭纤维 , 聚丙烯腈基炭纤维

New preparation of Mg-Li-Al alloys by electrolysis in molten salt

Wei HAN

金属学报(英文版)

This work presents a study on electrochemical formation of Mg-Li-Al alloys on an inert electrode (Mo electrode) in a molten KCl-LiCl-AlCl₃-MgCl₂-KF system. It aims at preparation Mg-Li-Al metal alloy directly under an optimal electrolytic parameters. Main factors which affect current efficiency are investigated. We have discussed the co-electrodeposition conditions and the effect of technical parameters on these experiments, and gained a good electrolytic process. The result of calculation shows that co-electrodeposition Mg, Li and Al occurs at the cathode current density higher than 9 A/cm² and electrolytic voltage between 6 to 9 V. And at the optimal parameters, 12-13 A/cm², 620-640 ℃, the highest current efficiency reaches as high as 86 %. Lithium combined with magnesium forms Li_0.92Mg_4.08 and Li₃Mg₇, and aluminum mainly exists in a form of Mg_0.58Al_0.42, distributing in the alpha phases and beta phases.

关键词: Mg-Li-Al , 熔盐 , 电解 , 共电沉积

Electronic Transport Properties of Sodium Tungsten Bronzes Nao.54WO3 Single Crystals

材料科学技术（英文）

关键词: 钠钨青铜 , 铜单晶 , 传输性能 , X-射线粉末衍射 , 电子 , 能量色散谱 , 经验公式 , 导电行为