The aim of this work is to study the NiP-B4C plating process, its operating conditions and formulations, composition, mechanical properties, microstructure and in particular, corrosion behaviour. Three main formulations were studied, two with low phosphorus content and one with high phosphorus content, and for each formulation different concentration of microparticles of B4C were added to the bath. Then every sample was submitted to different types of analysis: XRD in order to know the orientation of the crystalline structure, potentiodynamic tests to register the circulating current on the working electrode, SEM to have informations about the superficial morphology of the deposit. Furthermore some potentiodynamic tests stopped at predetermined potentials were performed, in order to better understand the evolving of the corrosion process. The samples were also subjected to a heat treatment and then other potentiodynamic tests were performed to verify the corrosion behaviour after annealing. Last task was to plate a cylinder with the same bath used for the flat plates and to check if the changing of geometry is affecting other parameters like corrosion resistance.
Lo scopo di questo lavoro è quello di studiare il processo di placcatura NiP-B4C, le sue condizioni di funzionamento e le formulazioni, la composizione, caratteristiche meccaniche, microstruttura e in particolare, il comportamento alla corrosione. Tre formulazioni principali sono stati studiate, due con basso contenuto di fosforo e uno con alto contenuto di fosforo, e per ciascuna formulazione una diversa concentrazione di microparticelle di B4C è stata aggiunta al bagno. Poi ogni campione è stato sottoposto a diversi tipi di analisi: XRD per conoscere l'orientamento della struttura cristallina, potenziodinamiche per registrare la corrente circolante sulla elettrodo di lavoro, SEM per avere informazioni sulla morfologia superficiale del deposito. Inoltre alcune potenziodinamiche sono state eseguite e fermate a potenziali predeterminati, al fine di comprendere meglio l'evoluzione del processo di corrosione. I campioni sono stati sottoposti anche ad un trattamento termico e poi altri test potenziodinamiche sono stati eseguiti per verificare il comportamento corrosione dopo ricottura. Ultimo compito era di placcare un cilindro con gli stessi bagni utilizzati per le piastre piane e per verificare se la modifica della geometria influenza altri parametri come la resistenza alla corrosione.
Electrodeposition of metal matrix composites with boron carbide microparticles
TUCCI, ALESSANDRO
2014/2015
Abstract
The aim of this work is to study the NiP-B4C plating process, its operating conditions and formulations, composition, mechanical properties, microstructure and in particular, corrosion behaviour. Three main formulations were studied, two with low phosphorus content and one with high phosphorus content, and for each formulation different concentration of microparticles of B4C were added to the bath. Then every sample was submitted to different types of analysis: XRD in order to know the orientation of the crystalline structure, potentiodynamic tests to register the circulating current on the working electrode, SEM to have informations about the superficial morphology of the deposit. Furthermore some potentiodynamic tests stopped at predetermined potentials were performed, in order to better understand the evolving of the corrosion process. The samples were also subjected to a heat treatment and then other potentiodynamic tests were performed to verify the corrosion behaviour after annealing. Last task was to plate a cylinder with the same bath used for the flat plates and to check if the changing of geometry is affecting other parameters like corrosion resistance.File | Dimensione | Formato | |
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https://hdl.handle.net/10589/112422