(1. 華南理工大學(xué) 化學(xué)科學(xué)學(xué)院，廣州 510640；
2. 廣州二輕工業(yè)科學(xué)技術(shù)研究所，廣州 510170)
摘 要: 采用電化學(xué)方法、掃描電鏡和X射線光電子能譜研究了鋅酸鹽鍍鋅層的三價(jià)鉻鈍化膜的電化學(xué)性能、表面結(jié)構(gòu)與成膜機(jī)理。結(jié)果表明：鋅酸鹽鍍鋅層的三價(jià)鉻鈍化膜表面結(jié)構(gòu)致密、無(wú)明顯裂紋，具有較好的耐腐蝕性能；這種鈍化膜表層與里層的組成不同，表層的組成為Cr2O3-Cr(OH)3-ZnO共混物；里層(離表層10~30 nm處)的主要組成為Cr2O3-ZnO-Zn共混物；鈍化膜的成膜過程可能包括鍍鋅層的溶解、堿性薄層的形成、膠狀膜的形成和膠狀膜轉(zhuǎn)化成鈍化膜4個(gè)步驟。
關(guān)鍵字: 鍍鋅；三價(jià)鉻；鈍化膜
ZHAO Guo-peng2, XIAO Zheng-wei1
（1.College of Chemistry, South China University of Technology, Guangzhou 510640, China;
2.Guangzhou Etsing Plating Research Institute, Guangzhou 510633, China）
Abstract:The electrochemistry behavior, surface microstructure and forming process of trivalent chromium passivation film were studied by electrochemical methods, scanning electron microscopy and X-ray photoelectron spectroscopy. The trivalent chromium passivation film based on zincate plating obtained has compact structure with no obvious crack, and excellent anticorrosion performance. Different compositions are detected from the surface to inner film, the surface mainly contains Cr2O3-Cr(OH)3-ZnO compound, the inner (10−30 nm to surface) composes of Cr2O3-ZnO-Zn.The forming process of passivation film possibly consists of four steps which are zinc dissolution, basic area appearance, gelatiniform film forming and converting to passivation film.
Key words: zincate plating; trivalent chromium; passivation film
