Abstract The objective of this study is to investigate the effect of silane and fiber laser treatments on the shear strength and failure type characteristic ofAA2024-T3/unidirectional carbon fiber-reinforced epoxy composite [0]8 laminates (Al/CFRP) adhesively bonded joints. Epoxy-based paste 2 part adhesive (Loctite EA 9396 AERO) was used for adhesive joining. Chemical surface treatment was tested with three different silane concentrations (1, 3 and 5 vol.%) applied to AA2024-T3 aluminum plates after cleaning. In addition, 50 W pulsed fiber laser was used to AA2024-T3 aluminum plates for laser treatment. For determining the optimum fiber laser parameters (laser power, frequency and scanning speed) L9 orthogonal array Taguchi method (3 variables and 3 levels) was used. The chemical composition of the fiber laser and silane treated AA2024-T3 sample’s was analyzed using Fourier transform infrared spectroscopy – attenuated total reflectance (FTIR–ATR). Shear strength values of the Al/CFRP bonded joints were determined by using single lap shear tests. From the test results, the silane concentration of 3 vol.% on AA2024-T3 aluminum plates had a significant effect on shear strength of Al/CFRP bonded joints (16.44 MPa) compared to untreated samples (6.46 MPa). In addition, it was determined that the laser treating parameters of scanning speed of 100 mm/sec, frequency of 80 kHz and power of 50 W laser power achieved the optimum surface of AA2024-T3 to be strongly bonded with CFRP (23.68 MPa). After mechanical tests, failure modes were also observed by using the digital camera.

中文翻译：

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用于Al/cfrp胶粘接头的Al 2024合金新型表面处理的比较

摘要 本研究的目的是研究硅烷和纤维激光处理对AA2024-T3/单向碳纤维增强环氧复合材料[0]8层压板（Al/CFRP）粘接接头剪切强度和破坏类型特征的影响。环氧糊状 2 部分粘合剂 (Loctite EA 9396 AERO) 用于粘合剂连接。用三种不同的硅烷浓度（1、3 和 5 vol.%）在清洁后应用于 AA2024-T3 铝板上测试化学表面处理。此外，采用50 W脉冲光纤激光器对AA2024-T3铝板进行激光处理。为了确定最佳光纤激光器参数（激光功率、频率和扫描速度），使用了 L9 正交阵列田口方法（3 个变量和 3 个级别）。光纤激光器和硅烷处理过的 AA2024-T3 样品的化学成分使用傅里叶变换红外光谱 - 衰减全反射 (FTIR-ATR) 进行分析。Al/CFRP 粘合接头的剪切强度值是通过使用单搭接剪切试验确定的。从测试结果来看，与未处理样品 (6.46 MPa) 相比，AA2024-T3 铝板上 3 vol.% 的硅烷浓度对 Al/CFRP 结合接头的剪切强度 (16.44 MPa) 有显着影响。此外，确定了100 mm/sec的扫描速度、80 kHz的频率和50 W激光功率的激光处理参数实现了AA2024-T3与CFRP（23.68 MPa）牢固结合的最佳表面。机械测试后，还使用数码相机观察了故障模式。