Dr. Jörg Pezoldt
Phone: +49 3677 69-3412
The aim of this project is to define basic rules for controlling or slowing down the formation of reactive materials by two- and three-dimensional structuring of the reactive multilayers. The influence of the lateral dimensions, the spatial arrangement and the geometric shape of the structured elements of the reactive multilayers on the ignition behavior, the propagation velocity of the reaction front and the phase formation is investigated. For flat binary reactive multilayers with infinite dimensions, the most important parameters controlling the reaction rate are the material combinations, the double layer thickness as well as the thickness of the individual layers and their microstructures. The occurring residual stresses, which are crucial for a reliable design of future devices, are identified by thermomechanically coupled numerical simulations and parameter identification by inverse modeling. The project will answer the following questions: How do lateral and vertical constrictions and the associated reaction path affect the tailor-made morphology? How can free surfaces and a material environment with locally adapted thermal conductivities be used to control the reaction path and morphology? How do local changes in morphology affect the reaction and can they be used for process control? How does the structuring of reactive multilayers affect the reaction and heat propagation? How can the joining process and the mechanical properties be controlled by applying the defined basic rules? With the focus on scaling and transfer processes, the project in collaboration with "Phase Simulation and Experimental Microstructure Research" and "Tailor-made Heat Release Properties for Reactive Joining Processes" contributes to the research and formulation of basic rules as a prerequisite for the integration of reactive materials into joining technology for different application areas.