No abstract

This paper summarizes the basic results of fatigue testing of bodies with both metallic and ceramic thermally sprayed coatings. Three kinds of ceramic coatings (Al 2 O 3 , Cr 2 O 3 , and olivine) sprayed with DC plasma under identical conditions were investigated together with metallic Ni-5wt.%Al coatings sprayed by wire arc, DC plasma, and HVOF. The elastic modulus of the deposited coatings was investigated using four point bending and resonance method. Bending fatigue tests at resonance frequency were performed with cantilever beam specimens. The processes taking place during the fatigue test are identified and discussed. The morphology of the fracture surfaces was investigated together with microstructure and porosity of the coatings.

I would also like to thank to other researchers and fellow students from our research group as well as NTU staff, especially in the Materials Laboratory A, who were in any way involved in this project. Provided support, expertise and hospitality, throughout the whole course of the project, will not be forgotten.