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在LiCl-KCl-MgCl_2-Gd_2O_3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,Gd_2O_3在LiCl-KCl熔盐体系中几乎不溶,而在LiCl-KCl-MgCl_2熔盐中有一定的溶解度,而且随着温度的升高,Gd_2O_3的溶解度也随之增大.循环伏安和计时电位研究表明,添加MgCl_2和Gd_2O_3后,Li的沉积电位向正向移动,当阴极电位小于-2.30 V或阴极电流密度大于0.776 A/cm~2时,可以实现Li,Mg和Gd共同析出.通过对电解条件的考察可知,电解温度对电流效率影响很大,当电解温度为873 K时,电流效率最大为78.87%.阴极电流密度高,则制备的Mg-Li-Gd合金中Li的含量较高.合金微观组织分析表明,在Mg-Li-Gd合金中存在Mg_3Gd相.Gd对Mg-Li合金有细化作用,而且随着Gd含量的增多,合金的晶粒细化越明显.由Gd元素的面扫描可知,Gd主要分布在晶界处.
The electrochemical behavior of molten salt was investigated by cyclic voltammetry and chronopotentiometry in the LiCl-KCl-MgCl_2-Gd_2O_3 molten salt system. Electrochemical chemical deposition was used to prepare Mg-Li-Gd alloy. XRD, SEM, EDS And OM.The results show that Gd 2 O 3 is almost insoluble in LiCl-KCl molten salt system and has some solubility in LiCl-KCl-MgCl 2 molten salt, and with the increase of temperature, the solubility of Gd 2 O 3 But also increase.The cyclic voltammetry and chronopotentiometric studies show that the deposition potential of Li moves forward when MgCl_2 and Gd_2O_3 are added.When the cathode potential is less than -2.30 V or the cathode current density is more than 0.776 A / cm ~ 2, Li, Mg and Gd can be precipitated together.According to the investigation of the electrolysis conditions, the electrolysis temperature has a great influence on the current efficiency, the maximum current efficiency is 78.87% when the electrolysis temperature is 873 K. When the cathode current density is high, The content of Li in Mg-Li-Gd alloy is high.The microstructure of the alloy shows that there is Mg_3Gd phase in Mg-Li-Gd alloy.Gd has the effect of thinning Mg-Li alloy, and with the increase of Gd content, The grain refinement of the alloy is more obvious.It can be seen from the surface scanning of the Gd element that Gd is the main one Distributed at grain boundaries.