ubc Microstructure evolution and strengthening mechanism in Ni-based composite coatings Microstructure evolution and strengthening mechanism in Ni-based composite coatings 2016-10-25 [Electronic ed.] prv Universitätsbibliothek Chemnitz Universitätsbibliothek Chemnitz, Chemnitz Fakultät für Maschinenbau Insitut für Werkstoffwissenschaft und Werkstofftechnik Professur Werkstoff und Oberflächentechnik male Teheran, Iran Ni electrodeposition is a suitable process for producing thick deposits and thick metallic microstructures, especially for producing relatively deep micromoulds in Microsystems industry. Ni-P deposits, due to their better properties compared to Ni deposits – particularly high mechanical properties (hardness, wear resistivity), corrosion resistance, magnetic properties, a higher fatigue limit and lower macroscopic deformation – can be a very good alternative for producing Microsystems, especially for MEMS or Microengines. According to few limited literature and our primary investigations, dispersion coating and adding particle into the electrolyte can be considered as an approach in order to decrease the stress and ease the deposition of Ni-P galvanically. Although in the last decades the influence of particles embedment in the matrix by electroplating techniques have attracted the scientific interest, there are still contradictions among the research community concerning the influence of codeposited particles on the microstructure and strengthening properties of Ni-based composites coatings. In many cases, it is believed that the enhanced mechanical performance of the coatings is mainly caused by a change in the microstructure of the metal matrix and not so much by the presence of the particles themselves. In other words, the role of particle characteristics - like their nature, size and concentration - on the layer features and strengthening mechanism of electrodeposited Ni-based composite coating with different matrix is not cleared well. Furthermore, the incorporation of particles into the deposit is mainly considered as a key factor for determining the composite coatings properties. Despite of existing models of ECD, the mechanism of particle incorporation into the film under influence of different particle characteristics has not been well understood yet. Therefore, the main aim of this study is to shed light on the effect of particle characteristics (size, concentration, type) on the codeposition process, microstructure and strengthening mechanisms in Ni and Ni-P electrodeposited composite coatings. 620 Verfestigung, Verbundwerkstoff, Beschichtung, Galvanotechnik Ni-basierte Galvanisierung, Schichtcharakterisierung, Galvanisierungsmechanismus, Verfestigungsmechanismus, Verbundwerkstoffbeschichtung Ni-based electrodeposition, layer characterization, electrodeposition mechanism, strengthening mechanism, composite coating urn:nbn:de:bsz:ch1-qucosa-211837 Technische Universität Chemnitz dgg Technische Universität Chemnitz, Chemnitz Amir Sadeghi 1983-03-10 aut Thomas Lampke Prof. Dr. dgs Andreas Bund Prof. Dr. rev eng 2016-05-17 2016-09-28 born digital Amir Sadeghi sadeghi.amir@web.de doctoral_thesis