Enhancing Joint Strength in Laser-Assisted Metal-to-Polymer Joining of Low-Carbon Steel and PETG through Surface Texturing and Laser Parameter Optimization
Purushottam Kumar, Bappa Acherjee, Joyjeet Ghose and Somnath Chattopadhyaya
Laser-assisted metal-to-polymer (LAMP) joining is a thermal bonding process that uses laser energy to create hybrid metal-polymer structures through adhesion and mechanical interlocking, without the need for adhesives or fasteners. In this study, the LAMP joining of AISI 1018 low-carbon steel and PETG (polyethylene terephthalate glycol) is investigated using a 1 kW fiber laser welding system. The effects of key process parameters, such as laser power, scanning speed, and surface texturing, on joint strength are analyzed. Three surface textures, namely transverse, longitudinal, and box pattern grooves, are applied to the steel surface, and the joint strength of textured samples is compared with non-textured joints. Bonding quality at the polymer-metal interface is examined, revealing strong adhesion and a mixed-mode fracture. An empirical model is developed to correlate laser power, scanning speed, and textured patterns with joint strength, validated through regression analysis and analysis of variance. The results show that textured patterns, particularly the box texture, improve joint strength. Additionally, laser power is found to be the most influential factor on joint strength, followed by scanning speed and the types of texturing used. The study also highlights the optimal process parameters, with maximum joint strength achieved at high laser power (600 W), high scanning speed (20 mm/s), and box texture.
Keywords: Hybrid metal-polymer structures, LAMP joining process, AISI 1018 steel, PETG polymer, surface texturing, joint strength