铝合金裂纹板的阳极化处理与复合材料补片胶接修理效果

采用磷酸阳极化方法对胶接修理铝合金裂纹板的粘接表面进行了处理,并用单向碳纤维/环氧复合材料补片对铝合金进行了修补.测试了阳极化铝合金的粘接性能、修补结构的静态力学性能和疲劳性能,考察了粘接表面的阳极化处理对修补结构的静态力学性能和疲劳性能的影响.结果表明,磷酸阳极化在铝合金表面形成多孔膜,复合材料补片修补胶接时胶粘剂能渗透进入阳极化铝合金表面的多孔膜,在粘接界面上形成一层过渡层,该过渡层的形成能有效提高其与复合材料的粘接性能,其粘接副的拉剪强度提高了104%;铝合金裂纹板胶接修理前的粘接表面的阳极化处理能大幅度地提高修复结构的静态强度和疲劳寿命,当用单向碳纤维/环氧复合材料补片单面修补时,修补结构的破坏强度为418.13MPa,恢复到完好板的93.42%;修补结构的疲劳寿命相对裂纹板延长了1.42倍,比未阳极化的修补板的疲劳寿命增加了27.59%.修补前的阳极化处理也使修补结构在一定周次疲劳后的剩余强度有所提高.

Anodizing Treatment and Its Effects on Properties of Cracked Aluminum Plates Repaired with Composite Patches

The center-cracked aluminum alloys plates were bonded repaired with unidirectional carbon/ epoxy composite patches, some of which were anodized in the aqueous solution of phosphoric acid. The adhesive properties of the anodized plates were investigated. The effect of anodizing on the static and fatigue properties of the repaired structure was analyzed. It is shown that the anodizing produces the porous and micro-rough film on the surface of plates. When the anodized plates are bonded with composite patches, the adhesive penetrates into the film and a transition layer is formed between the alloy and the adhesive. The adhesion is promoted greatly and the maximum lap shear strength of the anodized sample is 104% greater than that of the normal samples. The static and fatigue properties of the repaired plates are improved greatly after anodizing treatment. The failure strength of repaired plates is 418.13MPa when the plates are anodized, which is 93.42% of that of the no flaw plates. The fatigue life of repaired plates is 1.42 times longer than that of cracked plates when the plates are anodized, which is 27.59 % longer than that of the normally repaired ones. The residual strength of the repaired plates after a number of fatigue cycles is improved significantly when the cracked plates are anodized before repair.