铝合金阳极氧化膜干燥方式对其粘接性能的影响

Effects of drying methods of anodic films on adhesion properties of aluminum alloy

利用拉剪实验及楔子实验等测定2A14铝合金粘接件的结合强度和耐久性,结合扫描电镜及红外分析等方法,研究铝合金粘接前阳极氧化膜的微观结构及含水量对其粘接性能的影响。结果表明:铝合金磷酸阳极氧化膜经过冷风吹干、50℃烘干和100℃烘干处理后,粘接试样的拉剪强度随烘干温度升高略有增加;粘接试样的湿热耐久性以50℃烘干处理后的稍好,而100℃烘干处理后,由于氧化膜中产生大量微裂纹,使其耐久性有所下降;氧化膜经过沸水封闭处理后,由于膜中含水量很大及封孔处理限制了粘合剂的渗透,导致其拉剪强度和湿热耐久性皆明显降低。

The aluminum alloy samples were anodized in the phosphoric acid solutions, the microstructure and topography of the anodic films were examined using SEM and AFM, and their adhesive properties were studied by the lapshear test and wedge test. Prior to bonding, the PAA films were dried in cool wind, at 50℃, at 100℃, or sealed in boiling water. The results showed that the adhesive bonding strength of the alloy were slightly improved with the increase of drying temperature; the durability of bonding alloys by dried at 50℃ was slightly better than by dried in cool wind and at 100℃ because too high temperature resulted in forming lots of micro-cracks in anodic films. By water sealing, because the hydrature of anodic films was very high and the pores were blocked to limit the penetration of adhesive, their adhesive properties had a remarkable decrease.