Study of laser surface texturing on the adhesion properties of SHF-2D epoxy zinc paint

In this paper, laser surface texturing (LST) was performed on the surface of 6061 aluminum alloy using a pulsed laser, and then SHF-2D zinc epoxy coating (SP) was applied to the LST-processed surface. The adhesion performance under different laser spot overlap rates was investigated. The results show that the LST surface can increase the adhesion strength by 2∼3 times. The pattern of the spatter produced by laser irradiation determines the adhesion strength. The higher the height and the larger the spatter, the better it locks into the SP, thus effectively increasing the adhesion strength. The adhesion strength is greatest (up to 15.98 MPa) at a laser spot ratio of 10 %, due to the formation of an "upside-down" spatter. This splatter effectively locks into the paint in place, thereby greatly increasing the bond strength between the paint and the substrate.