Ni-SiC nanocomposite coating

Zhang, Z. et al.. Electrodeposition of Ni-SiC nanocomposite coatings based on the surface charge determination of SiC nanoparticles. Bull. Electrochem., 22, 189, 2006. 

The tribocorrosion behavior of ED Ni-SiC nanocomposite coated SS in 0.5 M K2SO4 reveals that the coating exhibits a stable FCP rmder static conditions and the application of friction destroys the passive oxide film, thus making the sirrface active and promoting dissolution. The overall performance of nanocomposite coatings under conditions of tribocorrosion is determined by the kinetics of mechanical removal of the passive layer with the applied friction and by the kinetics of the repassivation when the friction is stopped. 

Wear corrosion rate of electrodeposited pure nickel and Ni-nano SiC nanocomposite coatings in 0.5 M Na2S04 (pH 5.70) at different applied loads under the same test conditions as Fig. 8.19 (Benea et ai, 2002). 

However, during long exposures to medium-temperature operating conditions, e.g. 1000°C, spinel formation is certainly expected. Wang etal.60 demonstrated this for the Ni-alumina system, showing the diffusion of Ni atoms to the free surface of the nanocomposite, followed by the formation of a nickel spinel surface coating which then limits the kinetics of subsequent oxidation. In this case the formation of a spinel surface layer may be beneficial to mechanical properties, since the reaction results in a volume increase, and the formation of compressive residual stresses. An analogous behavior was reported for ceramic particle nanocomposites, where oxidation of SiC particles results in an increase in volume and compressive residual stresses.61... 

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