(中國(guó)海洋大學(xué) 材料科學(xué)與工程研究院，青島 266100)
摘 要: 采用磷酸鹽對(duì)AZ31鎂鋁合金鈰轉(zhuǎn)化膜進(jìn)行致密化處理，利用掃描電鏡(SEM)、X射線(xiàn)光電子能譜(XPS)和電化學(xué)方法等對(duì)致密化處理之后的膜層性能進(jìn)行表征，探討轉(zhuǎn)化膜致密化處理的作用機(jī)理。結(jié)果表明：轉(zhuǎn)化膜經(jīng)過(guò)致密化處理之后，膜表層裂紋減少，致密性得到改善，提高了對(duì)基體的覆蓋度，在NaCl溶液中的耐腐蝕性能提高。轉(zhuǎn)化膜中Ce4+的含量減少，部分鈰的氧化物/氫氧化物轉(zhuǎn)變?yōu)镃ePO4，降低了膜層中結(jié)晶水的含量，減少了裂紋的產(chǎn)生與發(fā)展，提高了膜層的性能。
關(guān)鍵字: 鎂合金；轉(zhuǎn)化膜；后處理；裂紋；腐蝕
（Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100, China）
Abstract:The densification process of cerium-based conversion film on AZ31 magnesium alloy was achieved by phosphate. The properties of the film and the densification mechanism were investigated exhaustively by scanning electronic microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and electrochemical methods. The results reveal that after the post-treatment the denseness of the cerium-based conversion coatings is improved, which benefits a lot from the reduced number of cracks. As a result, the corrosion resistance of the conversion film in NaCl solution is strengthened. The less Ce4+ ion, the transformation of hydrated cerium oxides to stable CePO4 and lower crystal water content in the films attribute to the reduce of the crack number and the improvement of the film performance.
Key words: magnesium alloys; conversion coatings; post-treatment; crack; corrosion
