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.
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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