Effect of surface texture on quality of stainless steel-PET transmission welding

Abstract

Metal-plastic joints are widely used in industrial production. Laser lap welding using polyethylene terephthalate (PET) side can effectively connect 304 stainless steel to PET. However, there are still several issues in this transmission welding. In this study, the scanning speed and pulse frequency of laser were optimized for producing the best texture grooves. The influences of surface texture grooves on laser absorption and strength of 304 stainless steel/PET joints were then investigated. The obtained results showed that the scanning speed and pulse frequency of laser have a great influence on the width and depth of texture grooves. On the premise of ensuring the formation of quality of a groove, the depth of the groove can be allowed to reach 69 μm. In the laser absorption rate experiment, the deeper and narrower the grooves, the higher was the laser absorption rate. This was consistent with the simulation results of the temperature field. The average temperature in the melting zone of the textured surface was 15.27 % higher than that of the non-textured surface. After welding, the tensile strength of the textured material in the joint was 35.26 MPa, which was 4.67 MPa higher than that of the non-textured material. This also showed that the texture treatment of stainless steel surface can not only improve the laser absorption rate of the surface, but also provide a mechanical anchoring effect and improve the tensile strength. Compared with that under non-textured material, the tensile strength of textured material under low energy parameters was found higher, which was conducive to the high-strength connection between metal and plastic.