LaCl_3对化学沉积Ni-Cu-P合金镀层性能的影响

Studies on the Effects of LaCl_3 Additive Solution on the Properties of Ni-Cu-P Coatings by Electroless Deposition

为提高钢材耐蚀性,采用中温酸性化学沉积的方法,在镀液中添加LaCl_3制备Ni-Cu-P合金镀层,并利用维氏硬度计、扫描电子显微镜、能谱及微取向系统、X-射线衍射仪及Autolab电化学工作站分别对镀层的硬度、微观形貌、成分、结构及耐蚀性检测。结果表明:1)镀层硬度随LaCl_3质量浓度增加先增加后减小;2)随镀液中LaCl_3含量的增加,Ni-Cu-P合金镀层结构由非晶态转变为晶态,在LaCl_3质量浓度为0.10 g/L时,所得镀层的晶胞尺寸较小;3)镀液中LaCl_3质量浓度为0.05~0.15 g/L范围内增加时,测得镀层的腐蚀电流密度有先降低后升高的趋势。

In order to improve the corrosion resistance of steel,Ni-Cu-P coatings were prepared by middle-temperature acidic electroless deposition through the addition of LaCl3 to the bath. The hardness,micro-morphology,coating composition,structure and corrosion resistance of the coatings were studied by Vickers hardness tester,scanning electron microscope（ SEM）,energy dispersive spectroscopy（ EDS） and micro-oriented system,X-ray diffractometer（ XRD） and electrochemical workstation Autolab. The results show that： 1） the coating hardness increases at first and then decreases with the increase of LaCl3 concentration; 2） with the increase of LaCl3 concentration in the bath,the structure of Ni-Cu-P alloy coating changes from amorphous state to crystalline state,when the concentration of LaCl3 is 0. 10 g/L,the size of the unit cell is smaller then others; 3） when the concentration of LaCl3 in the plating solution increases from 0. 05 to 0. 15 g/L,the corrosion current density of the coating decreases firstly and then increases.