(1. 東北大學(xué) 材料與冶金學(xué)院，沈陽 110004；
2. 沈陽理工大學(xué) 環(huán)境與化學(xué)工程學(xué)院，沈陽 110168；
3. 沈陽大學(xué) 表面工程研究所，沈陽 110044)
摘 要: 將鋁合金陽極氧化膜浸入勃姆石(AlOOH)溶膠中進(jìn)行封閉。以溶膠封閉膜表面密度、磷−鉻酸質(zhì)量損失、酸性點滴實驗、染色實驗為評價標(biāo)準(zhǔn)，對溶膠封閉進(jìn)行了正交實驗，然后研究溶膠的pH值、試片浸入溶膠時間對封閉膜表面密度和磷−鉻酸質(zhì)量損失的影響，獲得如下的較優(yōu)工藝條件：溶膠pH值為4~6，試片浸入溶膠時間為30 min，烘干封閉膜的溫度為80 ℃，烘干時間為6 h。溶膠法封閉后膜的點滴試液變色時間可達(dá)33 min，磷−鉻酸質(zhì)量損失低于3 g∙m−2。極化曲線顯示溶膠封閉膜的腐蝕電流密度比重鉻酸鹽封閉膜的降低2個數(shù)量級，其原因是溶膠不僅封閉了氧化膜的孔隙，而且在氧化膜的表面形成溶膠凝膠涂層。
關(guān)鍵字: 鋁合金；陽極氧化膜；AlOOH；封閉
（1. School of Materials and Metallurgy, Northeastern University, Shenyang 110004, China;
2. School of Environment and Chemical Engineering, Shenyang Ligong University, Shenyang 110168, China;
3. Institute of Surface Engineering, Shenyang University, Shenyang 110044, China）
Abstract: The anodised film on Al alloy was dipped in boehmite sol so as to replace dichromate salt sealing used in common. The orthogonal experiment evaluation criterions for sol sealing include mass density of sealed film, mass loss in solution of phosphoric acid mixed with chromic acid, acidic dropping test and dyeing test. The effects of pH of sol and dipping time in the sol on the surface density and mass loss of sealed films were investigated. The films exhibit good properties under conditions of dipping in sol with pH value maintained at 4−6 for 30 min, and then dried at 80 ℃ for 6 h. The time of dropping test of sealed films is up to 33 min. The mass loss rate is lower than 3 g∙m−2. The polarization curves show that the corrosion current density of sol sealed film is about 2 orders of magnitude lower than that of the film sealed by sodium bichromate, the reason is that sol particles can not only seal pores of anodized film, but also form sol-gel coating on anodized film.
Key words: aluminum alloy; anodized film; Al(OOH); sealing
