The Effect of SiC Nanoparticle Size on the Electrodeposition of Zn–SiC Nanocomposite Coatings from Citrate Bath

Abstract

A comparison is made between the codeposition behavior of Zn with SiC nanoparticles (NPs) of two average sizes: 56 nm and 90 nm. The SiC NPs are first characterized using transmission electron microscopy (TEM) and X-ray diffraction (XRD). Dynamic light scattering (DLS) is used to compare the surface charge of both kinds of SiC NPs suspended in aqueous citrate electrolytes. The effect of applied current density, hydrodynamic conditions, and total charge passed on the SiC content in the coating and electrodeposition rate is studied. The electrodeposited Zn-SiC coatings are characterized by wavelength dispersive X-ray fluorescence (WDXRF), scanning electron microscopy (SEM), and XRD. The results obtained confirm that Cit-Zn complexes are adsorbed on the surface of the SiC NPs, which are transported to the cathode and are codeposited with Zn during reduction. Zn-SiC incorporation may proceed also by mechanical entrapment of SiC agglomerates in the cavities and pores that are formed in the deposit under condition of relatively fast Zn deposition, which is accompanied by fast hydrogen evolution.

The Effect of Direct and Pulsed Current in the Presence of Surfactants on the Electrodeposition of Zn–SiC Nanocomposite Coatings

“…Citrates also provide the stabilization of the pH of electrolyte solutions, hence they are widely used in the electrodeposition of zinc and its alloys [55,56]. The electrolyte composition in this work was selected based on earlier studies of the electrodeposition of zinc-based alloys from aqueous citrate solutions [53,54,[56][57][58][59]. The only variable in the bath chemistry was the type of organic additive ( Figure 1).…”

“…Analysis was carried out using a Rigaku Primini spectrofluorimeter (Rigaku, Tokyo, Japan) with scintillation counters (LiF crystal). The weight percentage of SiC in the Zn-SiC composite was calculated from the Zn and Si weight percentages, as described elsewhere [27,53,54], assuming that all Si atoms are bound to C as SiC in a 1:1 molar ratio. The faradaic efficiency (FE) of the process was calculated, as described elsewhere [53,54], assuming that only zinc ions could be deposited on the cathode.…”

“…Previously we investigated, for the first time, the DC co-deposition of Zn-SiC from aqueous citrate bath with gelatin as a bath additive [53,54]. The optimal parameters of the zinc-citrate bath were chosen on the basis of the analysis of a thermodynamic model.…”

“…Zeta potential measurements confirmed the adsorption of citrate and citrate-zinc ions as well as gelatin molecules on the surface of the SiC NPs. It was shown that SiC co-deposition with Zn proceeds through the entrapment of ceramic NPs during the reduction of citrate-zinc ions firstly adsorbed on their surface as well as by the mechanical entrapment of NPs agglomerates in the cavities formed in the Zn deposit [53,54].…”

Ultrasound Supported Galvanostatic Deposition of Zn Coatings Reinforced with Nano-, Submicro-, and Micro-SiC Particles—Weak Acidic Chloride Baths

“…Reventi et al researched the preparation of Zn-SiC nanocomposites from weakly acidic chloride baths [ 28 ]. Recently, Kazimierczak et al published several papers which indicated the possibility of synthesizing Zn-SiC coatings from citrate electrolytes [ 29 , 30 , 31 ]. The number of published papers shows that zinc electroplating is still an active research field and work is still underway on a synthesis method that obtains coatings with much higher corrosion resistance than the zinc coatings currently used.…”