Heated press welding: analysis of the parameters influencing the mechanical strength of hybrid PA66/PA12 thermoplastic and S235 steel sheet joints

Abstract

ABSTRACT This study aims to optimize and characterize hot pressed polyamide/steel hybrid joints as a potential solution for reducing energy costs in public transport through structural lightweighting. The mechanical performance of these joints is compared to traditional bonding methods, specifically investigating two types of joints: PA66/steel and PA12/steel. A design of experiments approach is employed to explore the influence of process parameters, with a particular focus on the cooling rate and heating temperature as key factors. By determining the optimal process parameters, the study emphasizes the importance of reaching the polymer pyrolysis point and achieving the fastest cooling rate to achieve optimal results. The findings reveal that these hybrid joints exhibit comparable average shear strength values to bonded joints, showcasing their potential as effective joining methods. In conclusion, future developments in hybrid polymer/metal joining processes utilizing thermal methods should prioritize rapid and uniform heating at the polymer/metal interface to initiate pyrolysis selectively at the polymer surface for bond formation. Subsequent rapid cooling is essential to cease pyrolysis and prevent polymer degradation within its volume. These insights are crucial for successful implementation of such processes in various industrial applications.