Laser welding of polyamide-6.6 and titanium: a chemical bonding story

Hybrid materials are more and more common in biomedical applications, such as implants. However, assembling the materials is still challenging. Mechanical fastening solutions present durability problems, and adhesive solutions rarely combine strong mechanical properties and biocompatibility. To address these difficulties laser welding is a promising solution. It is a fast process with great design freedom that requires no additional material at the interface. Since the process is quite recent, the involved fundamental mechanism are not well understood. Hence this work aims at exploring the existence of a chemical bond between two materials: titanium and polyamide-6.6. Samples composed of a block of polyamide-6.6 welded to a titanium sheet were broken and analysed using XPS and ToF-SIMS. Results show more polymer in the weld and the chemical bond seems to be a complexation of titanium with the amide function

Influence of Aluminum Laser Ablation on Interfacial Thermal Transfer and Joint Quality of Laser Welded Aluminum–Polyamide Assemblies

Laser assisted metal–polymer joining (LAMP) is a novel assembly process for the development of hybrid lightweight products with customized properties. It was already demonstrated that laser ablation of aluminum alloy Al1050 (Al) prior to joining with polyamide 6.6 (PA) has significant influence on the joint quality, manifested in the joint area. However, profound understanding of the factors affecting the joint quality was missing. This work investigates the effects of laser ablation on the surface properties of Al, discusses their corresponding impact on the interfacial thermal transfer between the joining partners, and evaluates their effects on the joint quality. Samples ablated with different parameters, resulting in a range from low- to high-quality joints, were selected, and their surface properties were analyzed by using 2D profilometry, X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX). In order to analyze the effects of laser ablation parameters on the interfacial thermal transfer between metal and polymer, a model two-layered system was analyzed, using laser flash analysis (LFA), and the thermal contact resistance (TCR) was quantified. Results indicate a strong influence of laser-ablation parameters on the surface structural and morphological properties, influencing the thermal transfer during the laser welding process, thus affecting the joint quality and its resistance to shear load

Laser welding of polyamide-6.6 and titanium:a chemical bonding story

Hybrid materials are more and more common in biomedical applications, such as implants. However, assembling the materials is still challenging. Mechanical fastening solutions present durability problems, and adhesive solutions rarely combine strong mechanical properties and biocompatibility. To address these difficulties laser welding is a promising solution. It is a fast process with great design freedom that requires no additional material at the interface. Since the process is quite recent, the involved fundamental mechanism are not well understood. Hence this work aims at exploring the existence of a chemical bond between two materials: titanium and polyamide-6.6. Samples composed of a block of polyamide-6.6 welded to a titanium sheet were broken and analysed using XPS and ToF-SIMS. Results show more polymer in the weld and the chemical bond seems to be a complexation of titanium with the amide function