Structure-oriented analysis and modeling of microtopography of engineering surfaces for process description and analysis (SAMMTOP)
Final Report Abstract
Conventional field parameters are derived using all data points of a surface measurement by means of mathematical rules. In many cases, this means that the structure of the surface is only reflected in the parameters to a limited extent. The surface structures on the microscale, which are sometimes generated at great expense through targeted control and monitoring of manufacturing processes, can often be significantly responsible for the function of the surface. Riblets, for example, can lead to a significantly lower flow resistance. In addition, the microstructure is a direct consequence of the manufacturing process and can therefore provide information about its condition. The aim of this project was therefore to investigate approaches for structure-oriented analysis of technical surfaces. The focus was on the so-called feature characterization. Here, specific features are extracted by watershed segmentation in order to derive corresponding parameters. While corresponding methods for surface topographies have been standardized and established in the industry for years, the feature characterization for profiles (ISO 21920-2) was published three months before the start of the project, and the associated filter standard for watershed segmentation (ISO 16610-45) was published in February of this year. In accordance with ISO regulations, no implementation guidelines are proposed. The focus was therefore on the development of a unique algorithm for watershed segmentation and feature characterization for surface profiles, which was published as pseudocode. Implementations were realized in Matlab and Python, validated and made publicly available via Github. During the development of the implementation guideline, the existing scope for interpretation resulting from the transfer of the continuous models of the ISO standards to discrete measurement data was addressed in particular. Furthermore, the code can serve as reference software (soft gauge of type F2 according to ISO 5436-2). Based on this implementation, a profile generator was developed with which recurring structures can be extracted from a real profile and synthetic profiles can be generated with corresponding statistics on distribution and deviations from each other. Finally, the potential of feature characterization was demonstrated in various correlation analyses, e.g. by identifying the wear condition during turning or individual process parameters during grinding and lapping. The project has thus laid the foundation for numerous future research projects and industrial applications. Knowledge already gained and future findings could be incorporated into the next revisions of ISO 21920-2 and ISO 16610-45 and expand the existing toolbox.
Publications
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Comprehensive analysis of surfaces featuring functional characteristics by angular-resolved scattering light measurement. Optical Manufacturing and Testing 2024, 10. SPIE.
Eifler, Matthias; Brodmann, Boris; Müller, Alexander & Seewig, Jörg
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Feature characterization for profile surface texture. Surface Topography: Metrology and Properties, 13(1), 015032.
Müller, A.; Eifler, M.; Jawaid, A. & Seewig, J.
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mts public/feature characterization for profile sur face texture
Alexander Müller & Arsalan Jawaid
