Electrochemical behaviour in synthetic saliva of silane coated Ni/Cu/Ni Nd‐Fe‐B magnet for dentistry applications

Abstract

In this work the electrochemical behaviour in synthetic saliva of silane coated Ni/Cu/Ni Nd-Fe-B magnets for dentistry applications was assessed. A protective multilayer of N-propyl-trimethoxy-silane was deposited by dip-coating onto Ni/Cu/Ni Nd-Fe-B magnets. The corrosion process of the silanised magnets was experimentally studied by polarization and electrochemical impedance spectroscopy tests performed at increasing immersion time in synthetic saliva solution. The Ni/Cu/Ni plated cover is not able to provide good barrier protection in this electrolytic media, while an additional three-layer silane film guarantees better anti-corrosion properties and durability in synthetic saliva solution.

Corrosion Behaviors of Microarc Oxidation Coating and Anodic Oxidation on 5083 Aluminum Alloy

“…e capacitive reactance arc corresponds to the process of ions passing through the MAO coating, and the inductive arc corresponds to the desorption process of the adsorbed intermediate products [40][41][42]. Figure 9 presents the equivalent circuit used to simulate the EIS data, in which CPE f is the capacitance of the MAO coating, R pore is the resistance of defects, C dl is the double layer capacitance, R p is the polarization resistance, L is the inductive resistance, and R L is the inductive resistance, which is related to the active dissolution of MAO coating [43]. e fitted parameters in the equivalent circuit in Figure 9 are given in Table 3.…”

“…e capacitive reactance arc corresponds to the process of ions passing through the MAO coating [43]. e bias line at low frequency corresponds to the diffusion process of Cl - through the MAO coating [44].…”

“…Figure 11 presents the equivalent circuit used to simulate the EIS data, in which W is the Warburg impedance. W was used to fit the data of MAO coating suggesting the responses induced by diffusion in paths of semi-infinite length [43,44]. e fitted parameters in the equivalent circuit in Figure 11 are given in Table 4.…”