电流密度对镀锡板钝化膜厚度、成分及膜中铬元素的影响

镀锡板钝化过程中的电流密度对钝化膜的性能影响较大,同时膜的性能又与厚度、成分、Cr元素含量等因素相关。实验通过改变镀锡板钝化膜生成过程中的钝化电流密度,探究电流密度对生成的钝化膜的厚度和成分的影响,并使用X射线光电子能谱(XPS)对在此电流密度下得到的钝化膜中Cr元素的组元和价态进行分析。结果表明在电流密度由3A/dm~2变为0.5A/dm2时:钝化膜厚度变薄,钝化膜中Sn元素含量增加,Cr元素含量减小;钝化膜中Cr元素的组元均由单质Cr、Cr_2O_3、Cr(OH)_3构成且不发生变化,但各价态组分的相对含量发生改变,低价态Cr含量降低,高价态Cr含量升高;镀锡板钝化膜组成成分呈现层状分布。

The influence of electric current density on the thickness,ingredient and chromium element in the tinplate passivation film

The current density of the tinplate in the passivation process has a great effect on the performance of the passivation film and these properties are closely related to the thickness,composition and chromium contents in the film. Influence of film’s thickness and ingredient caused by changing the current density during the process of tinplate passivation was studied.X-ray photoelectron spectroscopy(XPS) was used to analysis the component and valence state of chromium in the film generated under the certain current density. Results showed that when the electric current density changed from 3 A/dm² to 0.5 A/dm²,the thickness of passivation film is thinning,the contents of Sn element is increasing and the Cr element decreased;chromium component in the film was mainly consisted of Cr,Cr₂O₃ and Cr(OH)₃,and the composition was not changed,but the relative content of each valence components changed,the content of low state Cr decreased while the content of high state Cr increased;component of tinplate passivation film was rendering layered distribution.