浅析铝合金汽车轮毂无铬钝化剂成膜机理

Analysis on Film Forming Mechanism of Chromium-Free Passivation Agent for Aluminum Alloy Wheel Hub

为了对铝合金汽车轮毂用无铬钝化成膜的成膜机理进行研究,采用电化学方法结合X射线光电子能谱(XPS)、原子力显微技术(AFM)研究铝合金汽车轮毂无铬化学转化膜的成膜作用及其成膜机理。结果表明,在化学转化膜的形成过程中,有机物和锆、氧化合物将竞争生长,成膜初期无机锆、氧化合物具有较快的反应成膜速度,随着成膜时间的延长,有机物组分硅烷、树脂慢慢形成化学键成膜,形成无机/有机完整连续体,从而起到更好的耐腐蚀协调作用。

In order to study the film forming mechanism of chromium-free passivation film for aluminum alloy wheel hub,the film-forming effect and mechanism of chromium-free chemical conversion film on aluminum alloy automobile wheel hub were studied by electrochemical method combined with X-ray photoelectron spectroscopy(XPS)and atomic force microscopy(AFM).Results showed that during the formation of chemical conversion film,organics,zirconium and oxygen compounds would grow competitively.At the initial stage of film formation,inorganic zirconium and oxygen compounds had faster reaction and film forming rate.With the extension of film forming time,silane and resin,organic components,slowly formed chemical bonds to form a film,forming an inorganic/organic complete continuum,thus playing a better cor-rosion resistance coordination role.