铝合金表面复合硅烷化膜层的制备及分析

Preparation and Analysis of Composite Silylanization Film on Aluminum Alloy Surface

为了提高铝合金表面的耐蚀性和与有机涂层的粘结耐久性,对铝合金进行水煮(65℃×15 m in)处理,在其表面形成富含羟基氢氧化物层,然后经两步浸涂后再高温固化(100℃×60 m in),在被氧化的铝合金表面形成双-[3-(三乙氧基)硅丙基]四硫化物(BTSPS)和γ-缩水甘油醚丙基三甲氧基硅烷(GPTMS)复合硅烷化膜。用反射吸收红外光谱、俄歇电子能谱仪(AES)和扫描电子显微镜(SEM)对复合膜层进行了分析和表征。结果表明,在富含羟基氢氧化物的铝合金表面与BTSPS内膜层形成A l-O-Si共价键网络,BTSPS内层与GPTMS外层形成Si-O-Si共价键网络,环氧乙基位于复合膜层最外层。

In order to improve anti-corrosion property of aluminum alloy and bonding durability between aluminum alloys substance and organic coating,Al-alloy was cooked firstly in de-ionized water at 65 ℃ for 15 min and oxyhydroxide layer formed on Al-alloy surface, and then bis-[triethoxysilylpropyl] tetrasulfide （BTSPS） and γ-glycidoxypropyhrimentoxysilane （GPTMS） composite silylanization film layer formed on oxidized Al-alloy surface by two-step dip-coating process with further cure at 100 ℃ for 60 min. The composite film was analyzed by reflection-absorption FFIR spectrum, atomic emission spectroscopy （AES） and SEM. The results show that the Al-O-Si covalent bond network forms between oxy-hydroxide film layer on Al-alloy and BTSPS inner film, and Si-O-Si covalent bond network forms between inner BTSPS and GPTMS outer layer. Epoxy ethyl group lies in outmost composite film.