Sintesi di compositi di nichel con materiali micro/nano strutturati a base di carbonio per elettrodeposizione

A composite coating is a multiphasic material containing at least two species or phases in a way to synergically combine the properties of each single compound. Electrodeposition of nickel-diamond composites is carried out from a sulfamate bath containing up to 100 g/l of dispersed diamond particles with size 0.5-1 m. Deposits with high amount of embedded particles, homogeneously and finely dispersed in metal matrix, are obtained. Microhardness and wear resistance of the composites are investigated: both properties are highly influenced by the volume fraction of incorporated diamond particles. Morphology of the coatings and the effects of codeposited particles on metal matrix structure are also reported. The influence of pulse plating processes on current efficiency, particle co-deposition, surface morphology and microhardness of the composite coatings is investigated with diamond particles of different sizes (a) 0.5-1.0 m; b) 4-6 m; c) 10-15 m). Nickel matrix composites with multi walled carbon nanotubes MWNT and single walled nanohorns SWNH are obtained from a sulfate-chloride and sulfamate based solutions respectively.