Modelling of electrical contact resistances at metal plastic interfaces

• Applicants: Professor Dr. Ludwig Brabetz; Professor Dr.-Ing. Hans-Peter Heim
• Subject Area: Plastics Engineering ; Synthesis and Properties of Functional Materials
• Term: from 2020 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 437141536

An important aspect for the use of electrically conductive modified plastics is their contacting.In addition to methods which subsequently make contact (e.g., pinch or fuse contacts), there are also numerous process-integrated methods.Especially injection molding, but also the integration of other common primary forming, transforming and joining methods is conceivable. All these contacting possibilities lead to a specific state in the interface which can be described by local variables (e.g., filler position, crystallinity, etc.).The idea of the research project is to make a model description of the electrical contact resistance based on these local variables. In a subsequent step, this descriptive model will be used as the basis for a quantitative prediction of the interfacial resistance. For this purpose, specific states of the local variables are generated, and the contact resistance is measured. This depends on a precise adjustment of the local variables and on a reproducible and accurate measurement of the contact resistance. For the measurement of the contact resistance, classical measuring methods in combination with simulative approaches and additionally direct physical measurements at the interface are developed and used.Different states of the local variables can only be adjusted indirectly via adjustable variables as for example, the cylinder temperature during injection molding. Accordingly, submodels are required to describe the relationship between indirectly adjusted local variables and directly adjustable process variables. To validate the significance of the quantified model and its predictions, different application-typical contacting scenarios are finally generated, and the resulting contact resistances are compared with the model values. By processing the model equations for FEM applications, the possibility is created to implement the modeling in combination with existing simulation methods such as injection molding simulations or electrical simulations.

• DFG Programme: Research Grants