工艺参数对低pH值2.0~2.5柠檬酸水溶液电沉积铼铱基合金薄膜特征影响

研究了在低pH值2.0~2.5的柠檬酸水溶液中恒电流电沉积富Re+Ir的Re-Ir-Ni合金薄膜特征，以及镀液温度、镀液pH、电流密度和镀液化学组成对薄膜表面形貌、化学成分和晶体结构的影响。采用环境扫描电子显微镜、X射线能谱仪和X射线衍射仪分别对合金薄膜的形貌、成分和物相进行了表征。结果表明：在电流密度为60 mA·cm^-2、pH为2.0时，获得致密光亮的Re-Ir合金薄膜。在pH=2.5时，提高镀液温度可获得质量良好的合金薄膜，而pH=2.0时，则相反。在镀液温度60~70 ℃、pH=2.0时，沉积的合金薄膜由非晶相组成；在镀液温度80 ℃时，薄膜由ReO₃相组成。在电流密度为60 mA·cm^-2、pH值从2.0增加到2.5时，合金薄膜的晶形结构由非晶态转变为晶态和非晶态的混合结构。结晶相为hcp-Ir_0.4Re_0.6和hcp-Ni。

Effects of Electroplating Variables on Characteristics of Re-Ir-based Alloy Films in Citrate Aqueous Solutions with Low pH of 2.0~2.5

The characteristics of (Re+Ir)-rich Re-Ir-Ni alloy films electroplated galvanostatically from citrate aqueous solutions with low pH of 2.0~2.5 were investigated. The effects of electroplating variables and bath chemistry on surface morphology, chemical composition and crystallographic structure of the films were studied. The morphology, composition and phase of the alloy films were characterized by environmental scanning electron microscopy, X-ray energy dispersive spectroscopy and X-ray diffraction, respectively. The results show that a dense and bright Re-Ir alloy file is obtained under the conditions of current density of 60 mA·cm^-2 and pH=2.0. Increasing temperature results in good quality of the alloys at pH=2.5, but at pH=2.0 the result is opposite. The films deposited at bath temperatures of 60~70 °C and pH=2.0 consist of amorphous phase. At bath temperature of 80 °C, the films consist of ReO₃ phase. At current density of 60 mA·cm^-2, the crystallographic structure of the film changes from an amorphous phase to a mixture of crystalline and amorphous phases when pH is increased from 2.0 to 2.5. The phases of crystalline are hcp-Ir_0.4Re_0.6 and hcp-Ni.