电沉积铀靶制备技术研究

Preparation of Uranium Targets by Electro-Deposition Method

研究了在水溶液体系中采用电沉积法制备铀靶的方法。以0.15mol/L草酸铵为电解液,铂丝为电极,通过考察阴极处理工艺、电流密度、电沉积时间、pH、温度、搅拌速度、镀液中UO2(NO3)2浓度等对电沉积效率及镀层质量的影响,确定了制备电沉积铀靶的最佳工艺参数,其中,沉积效率通过紫外分光光度法测得。在pH=2～3、电流密度60mA/cm2、保持温度60℃、镀液中UO2(NO3)2浓度约1.67mg/mL时沉积效率可达约98%。采用红外光谱、X射线能谱和扫描电镜等对铀沉积层进行了测试。结果显示,铀以水合聚合物的形式存在,可能的结构为[UO2(H2O)4-O-UO2(H2O)4-O],铀的沉积层的纯度较高,除检测到铀(65.35%)、氧(27.38%)、碳(5.46%)和铂(1.81%)外未引入其他杂质,镀层表面平整、致密,与衬底结合牢固。单次铀的电沉积层厚度可达6mg/cm2,采用高温烧结后重复电镀的方法可将电沉积铀的密度提高到6～8mg/cm2。

The uranium targets were prepared by electro-deposition method.A hydrated uranium dioxide films were electrodeposited into stainless steel plates using uranyl nitrate in ammonium oxalate solution.The results show that the deposition efficiency of the uranium depends on many parameters,such as pH,supporting electrolyte,current density,and cell design.The electro-deposition yield was obtained in thick film samples using ultraviolet-spectrometric analysis of the electrolytic solution before and after the electro-deposition process.The optimized parameters were obtained by investigating the depositing temperature,time,concentration and pH of the supporting electrolyte.Electronic deposit was performed at 60℃ with pH=2-3,current density 60mA/cm2.The effect of UO2（NO3）2on uranium depositing shows an increase in efficiency as the electrolyte molarity increases at lower electrolyte concentrations,reaches the maximum at 1.67mg/mL.The uranium films,which are thin,adherent with a yield of 98%at the thickness of near 6mg/cm2 were characterized by infrared spectrum,scanning electron microscope,and X-ray spectrum.Its possible structure composing of uranium target is [UO2（H2O）4-O-UO2（H2O）4-O].XPS analysis shows that there is no elements other than uranium（65.35%）,oxygen（27.38%）,carbon（5.46%）and Pt（1.81%）being detected.The thickness of uranium films would reach 6-8mg/cm2 if repeated plating was adopted after sintering.