Fractal analysis and surface characterization by atomic force microscopy and other methods
1999 (English)Licentiate thesis, comprehensive summary (Other academic)
This licentiate thesis focuses on fractal analysis of surfaces measured with atomic force microscopy (AFM) and other microscopic methods, and the correlation between fractal dimensions and tensile strength for pre-treated stainless-steel surfaces. The disadvantage is that the probe biases the image and the roughness measurement. This has been investigated on simulated fractal surfaces scanned with a simulated pyramidal standard AFM tip, and we demonstrate that the fractal dimension is, underestimated, explaining why higher fractal dimensions are rarely reported in the AFM literature. The results of the simulations are applied to real fractal graphite samples, to shown how the simulations can be used to derive real fractal dimensions. Other surfaces with fractal behavior are pre-treated stainless-steel surfaces used to test the adhesion strength in a single joint lap. The weak relation between traditional roughness parameters and strength of the bond has made the use of fractal analysis appealing. These ideas are tested and evaluated by four microscopic methods and five fractal algorithms. We show that there is a relationship between fractal dimension and tensile strength at the length scale of the profiler i.e., 0.5 - 100 micrometer, and that the conventional parameter Ra is strongly connected to the magnitude of the surface.
Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 1999.
Licentiate thesis / Luleå University of Technology, ISSN 1402-1757 ; 1999:62
Research subject Fysik
IdentifiersURN: urn:nbn:se:ltu:diva-16854Local ID: 049fe0a0-d7e9-11db-a1bf-000ea68e967bOAI: oai:DiVA.org:ltu-16854DiVA: diva2:989841
Godkänd; 1999; 20070321 (ysko)2016-09-292016-09-292016-10-19Bibliographically approved