Investigation of the Effect of Varying Laser Scribe Sizes on the Adhesion Performance of the Aa2024-T3/Cfrp Joints Depending on the Number of Laser Scan Repeats

Abstract

One of the laser surface treatment parameters of “scan repeat number” was optimized for the adhesion performance of AA2024-T3/CFRP joints according to the variation of laser scribe sizes. Laser surface structuring was performed with previously optimized laser machine parameters from 1 to 9 “scan repeat number”. After laser surface treatments with the increased scan repeat number, the characterization of the substrate was established by surface morphology and the dimensions of laser scribes. The adhesive bonding of laser-treated AA2024-T3 and untreated CFRP was applied and single-lap shear tests were then performed. The fracture surfaces of substrates were observed and analyzed to determine failure modes. The results indicated that laser scribe geometrical parameters have a significant effect on the adhesion performance of AA2024-T3/CFRP joints. The adhesive bonding strength was enhanced and the maximum value was 26.48 MPa (with 5 scan repetition) increasing by 39% compared to the adhesive joints without surface treatment of AA2024-T3 adherend. The observed failure modes on both the adherend surfaces have demonstrated that the mechanical interlocking mechanism between the adhesive and laser textured aluminum adherend with optimized scan repeat number has been well-worked.

Keywords

• Laser treatment
• Adhesive bonding
• AA2024-T3
• CFRP
• Mechanical interlocking

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