(北京航空航天大學(xué) 材料科學(xué)與工程學(xué)院，北京 100083)
摘 要:
在含有硅酸鈉和硅溶膠的氧化溶液體系中，利用工頻交流電源對AZ91D鎂合金材料表面進(jìn)行陽極氧化處理，同時探討氧化電壓對膜層表面形貌、生長速率和耐腐蝕性能等的影響規(guī)律。結(jié)果表明：氧化過程存在一個明顯的臨界電壓值(170 V)，在電壓大于170 V陽極氧化反應(yīng)劇烈、氧化電流增大、試樣表面出現(xiàn)弧光放電。當(dāng)電壓小于170 V時，鎂合金表面則以均勻的桔黃色火花放電，獲得的氧化膜層表面光滑、均勻、致密，而且膜層的生長速率和耐腐蝕性隨著電壓的增加而增大；當(dāng)電壓超過這個臨界電壓值時，獲得的氧化膜層表面變得粗糙，其生長速率大幅提高，但膜層的耐腐蝕性能下降。
關(guān)鍵字: AZ91D鎂合金；陽極氧化；電壓；交流電源
（School of Materials Science and Engineering, Beihang University, Beijing 100083, China）
Abstract:The anodic films on AZ91D magnesium alloy were prepared in the electrolyte of Na2SiO3 and silica sol by AC sources. The effect of anodic voltage on the surface morphologies, growth rate and corrosion resistance of anodic films was investigated. The results show that the anodic reaction is rapid and the current increases quickly and the specimen’s surface is bestrewed with arc discharge when the anodic voltage exceeds 170 V. When the anodic voltage is less than 170 V, bisque sparks appear on the surface of magnesium alloy uniformly. The anodic films are smooth, uniformity and compact. Moreover, the growth rate and corrosion resistance of the anodic films is improved with increasing anodic voltage. When the anodic voltage is more than 170 V, the anodic films become coarse and their corrosion resistance is worse though their growth rate is extremely increased.
Key words: AZ91D magnesium alloy; anodic oxidation; voltage; AC power source
