Adhesion enhancement of PEEK/6161-T6 FLJ joints via laser surface modification

Abstract

The metal-thermoplastic hybrid structure has been widely employed in the aviation and aerospace industry. In this work, we developed a feasible way of laser surface texturing to address the poor adhesion between PEEK and 6061-T6 aluminum alloy. With the laser surface modification on 6061-T6 aluminum alloy, the PEEK/6061-T6 friction lap joining strength was improved significantly. The experimental results showed that the tensile shear strength between PEEK and 6061-T6 with laser textured surfaces achieved the maximum of 48.14 MPa. The enhanced bonding strength was attributed to the mechanical interlocking at the interface between PEEK and 6061-T6 caused by periodic micro-pores and nano-particles. After the progress of laser surface texturing, the double-scale hierarchical structures were produced on the surface of modified 6061-T6 alloy, leading to the formation of superhydrophobic or hydrophobic surfaces. Besides, quantitative fractal analysis of 6061-T6 surfaces was performed to study the relation between the morphology of 6061-T6 surface and the adhesion property of PEEK and 6061-T6. The results indicated that the superhydrophobic surface of 6061-T6 exhibited higher adhesion property with PEEK than the hydrophobic surface. A flawless interface was observed in the joint of PEEK and 6061-T6 with the superhydrophobic surface, compared to the voids observed at the interface of PEEK and 6061-T6 with the hydrophobic surface.