WEB Self reactive joining process with multilayer foils in lap joint configurationThursday (27.02.2020) 06:30 - 06:30 Poster Room Part of:
The application of reactive multilayer foils allows to join temperature-sensitive components with minimal thermal influence as a result of extremely fast joining velocities and therefore short heating durations. Initial experiences and skills in the area of micro joining in semiconductor and electronic industries should now also be transferred to macroscopic dimensions.
For this purpose the DFG project “tailored heat release characteristics for reactive joining processes” – subproject of project group “macro joining - heat release and microstructures in reactive joining” aims to transfer this knowledge to a macroscopic scale. Both, symmetrical (identical joining partners) and asymmetrical lap joints (different joining partners and/or different material thicknesses) are created at room temperature, with reactive multilayer foils as the local heat source in the joining zone. With the additional consideration of structuring the surfaces of the joining partners it becomes possible to investigate the complex interaction between surface structure joining process and the reactive films. Therefore, the characterization of the bonding mechanisms and quantification of the contributions of the different bonding mechanisms to the strength of metal and thermoplastic joints can be achieved. Through the combination of experimental analysis with numerical simulation a theoretical investigation of the thermal flow in the foils and in the metal and plastic components, for different dimensions and reactive multilayer morphologies, interlayer and surface structures of the joining partners will be executed. The velocity of the reaction front propagation as well as the thermal behaviour are determined by experimental investigations with high speed camera and pyrometry.
For all manufactured joints the bonding quality is evaluated based on experimental characterization methods which are necessary to investigate the correlations between the morphologies of the reactive multilayer foils, the actual components and their surface structures, bonding mechanisms and load-bearing capacities. Next to the evaluation of the temperature-time-curve in the joining zone for the joining of metals or thermoplastics with reactive multilayers, the research project aims to design specific tailored reactive foils to facilitate the temperature control in the joining as well as the heat affected zone and therefore provide asymmetric heat flow for joining dissimilar materials.