Enhancing interfacial bonding strength in fiber-metal laminates through burnishing and laser texturing surface treatments for improved mechanical performance

Fiber-metal laminates (FMLs) are increasingly used in the aerospace industry due to their superior mechanical properties, such as high strength, fatigue resistance and impact tolerance. However, achieving optimal interfacial bonding between metal layers and fiber-reinforced polymer (FRP) sheets remains a challenge, as this interface is critical for the overall performance of FMLs. This study focuses on enhancing the interfacial bonding strength between metal and FRP sheets through advanced surface treatment techniques applied to the metal layers. Specifically, two surface treatments burnishing and laser texturing are explored for their potential to improve mechanical properties. Burnishing is employed to induce compressive residual stresses and refine the metal surface, while laser texturing is used to create micro-scale surface patterns that increase surface roughness and promote better adhesion. Experimental results show that both treatments, especially in the case of the laser treatment, significantly improve the bonding strength and enhance the mechanical performance of the FMLs, particularly in terms of tensile strength and delamination resistance. These findings provide valuable insights into the optimization of FML manufacturing processes to meet the increasing demand for lightweight, high-performance composite materials.