Nickel matrix micro/nano SiC composite electrodeposition
Tutor / director / evaluatorFedrizzi, Lorenzo
Document typeMaster thesis (pre-Bologna period)
Rights accessOpen Access
Electrochemical codeposition is widely used in the last decade to produce composite metal matrix coatings. Hard particles such as oxides or carbides embedded in a metal matrix coating aim to increase its mechanical and wear properties. The use of nanometric particles could also change the microstructure of the electrodeposits leading to a more compact structure and thus to an increased corrosion resistance. The aim of this work is the production of pure nickel, nickel containing SiC micro-particles and nickel containing SiC nano-particles electrodeposits. The electrodeposition was carried out using a nickel sulphamate plating bath containing or not suspension of micro/nano sized SiC particles. The deposition was done using both direct and pulse current at different frequencies. The produced deposits have been characterized regarding their microstructure, SiC content, microhardness and corrosion resistance in a CO2 containing media. The microstructure has been observed by SEM (Scanning Electron Microscope) on top surface and cross section after metallographic etching. The SiC content was evaluated by GDOES (Glow Discharge Optical Emission Spectroscopy). The microhardness was measured in cross section to avoid the influence of the substrate. The corrosion resistance in a CO2 containing media was evaluated by potentiodynamic polarization curves.