A numerical illustration of the fusion bonding process

Abstract

Fusion bonding is an innovative joining technology which enables connecting load-adapted material combinations, such as metals with thermoplastic polymers or fibre-reinforced polymers. The bonding process is facilitated by inductively or conductively heating the metallic joining partner and pressing it onto the plastic joining partner. Due to heat conduction, the plastic melts and wets the metallic joining partner, so that after a holding and cooling phase a bonding results without applying additional joining technologies. The connection quality and bonding strength are linked to the selected process parameters and to achieve the desired outcome, it is crucial to choose the appropriate bonding process parameters. The experimental determination of such is an intricate and complex procedure in terms of costs and time efficiency, and hence simulations have become the preferred method for the dimensioning of joints. This paper discusses the numerical illustration of the fusion bonding process between a metal and a pure plastic hybrid joint. The temperature distribution in the joining partners is a significant process parameter that affects the connection quality and bonding strength. Simulations already exist that can predict such temperature distributions. 4,5 This paper builds upon a fully coupled thermal-stress analysis of the fusion bonding process and examines a possible numerical illustration of temperature distribution and mechanical displacements to make predictions about the geometric quality of the joints. For this purpose, the paper sets out to characterize the material behaviour of the polymer and hence generates material core values for the implemented material model in the simulation. The primary focus in this paper is on the temperature and shear rate-dependent viscoelastic behaviour of the plastic throughout the entire joining process temperature range. For the validation of the simulation, a real experiment has been carried out under ideal conditions.