Laser heat conduction joining of polycarbonate and aluminum alloy

The present work demonstrates the laser heat conduction joining (LHCJ) of polycarbonate and aluminum alloy. The experiments are performed to examine the impact of scan speed and laser power on the joint’s strength and quality. The bonding between the substrates was assessed by examining the cross-section using a scanning electron microscope and conducting energy-dispersive X-ray spectroscopy. The fractured surfaces are inspected by an optical microscope to explore the bond morphology. A finite-element-based numerical model is developed for the estimation of interface temperature and validated with the experimental results. Results of lap shear tests show that the weld strength is significantly affected by the laser power, scan speed, interface temperature, and bubble area. Microscopic observations of the joint interface disclose bubble area and mechanical interlocking between polycarbonate and aluminum. Through X-ray photoelectron spectroscopy (XPS) analysis, it was discovered that the interface experiences chemical bonding facilitated by the formation of Al-O-C bonds, which effectively enhances the strength of the joint.