Multi-signal far-field Microscope

• Subject Area: Mechanical Properties of Metallic Materials and their Microstructural Origins
• Term: from 2019 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 413728901

Engineering systems subjected to mechanical or thermal loading can undergo irreversible changes of state, which start at a microscopic level and may eventually cause catastrophic failure. From a mechanical point of view, these micro-changes are accompanied by localized deformations which are accessible by optical far-field microscopy using in-situ observation and modern image-based deformation analysis. There is also a corresponding temperature field, as irreversible processes are always associated with a dissipation of energy in terms of heat. However, conventional thermography cannot be used for measuring these dissipative effects, as there are physically based limitations to its spatial resolution, which are well above the length scale of the micro-changes in question. The solution to this fundamental problem is given by exploiting thermal luminescence and combining it with far-field microscopy in the form of a multisignal far-field microscope.Micro-scaled correlation of temperature and deformation or even fluid motion will greatly improve the understanding of ageing and damage processes, and will generate new and surprising engineering systems in their wake. The members of the consortium will address genuine damage processes in materials such as micro-crack formation or ageing in polymer materials, but also fluid-structure interaction typical for heat transfer systems. An area of particular interest is tribology. In this field, the sliding motion is studied of two rough surfaces against each other, which can produce substantial amounts of heat, but also deformation induced damage in terms of gradual material removal. The classical answer to this problem is to manufacture smooth surfaces and minimize surface roughness. However, there are examples in nature and in technology where textured surfaces give better tribological answers. Such surfaces can nowadays be manufactured by 3D printing or additive manufacturing. Hence one of the major goals of the planned research projects is exploiting the almost unlimited possibilities of additive manufacturing in surface design for new and exciting solutions to the old problem of friction and wear.

• DFG Programme: Major Instrumentation Initiatives
• Major Instrumentation: Encoded Stereo Microscope
• Instrumentation Group: 5040 Spezielle Mikroskope (außer 500-503)
• Applicant Institution: Universität Kassel
• Leaders: Professorin Dr. Angelika Brückner-Foit, until 9/2020; Professorin Dr.-Ing. Andrea Luke, since 10/2020
• Participating Person: Dr.-Ing. Frank Zeismann