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.