Study of Zn-Ni Alloy Coatings Modified by Nano-SiO₂Particles Incorporation

Abstract

The aim of this research work was to codeposit nano-SiO2particles into Zn-Ni alloy coatings in order to improve some surface properties. It had been investigated the effect of loading the plating bath with nanoparticles on composition, morphology, phase structure of deposits, and their subsequent influence on the corrosion process in corrosive solution of 3% NaCl and the thermal stability of deposits at200°C. It was found that Zn-Ni alloy composites contain a higher percentage of Ni with incorporation in the deposit of 1.54% of silica. X-ray diffraction measurements revealed that the alloys consisted of two phases, pure zinc andγphase. Electrochemical characterization of the composites had been carried out through potentiodynamic polarization and electrochemical impedance spectroscopy. The composites exhibited higher values of microhardness and better corrosion resistance in corrosive media.

Study of Particle Incorporation and Performance Characteristic of Aluminium Silicate-Zirconia Embedded on Zinc Rich Coatings for Corrosion and Wear Performance

“…The improvement can be attributed to the formation of favourable intermetallic phases in the alloy, which are suspected to behave like true compound. The presences of these phases are concluded to mitigate external forces and they act as dislocation motion barrier with attendant reduction in grain growth [31,32]. This is in line with SEM observations that reflect fine and uniform grain sizes, which confer surface strengthening effects on materials.…”

Electrochemical studies of sol-enhanced Zn–Ni–Al2O3 composite and Zn–Ni alloy coatings

“…Zn-Ni composite coatings including Zn-Ni-Al 2 O 3 [9], Zn-Ni-TiO 2 [10,11], Zn-Ni-SiO 2 [12] and Zn-Ni-SiC [13] have been synthesized by adding micro/nano-ceramic particles into the plating solution as a suspension during the electrodeposition, which allowed the particles to be incorporated into the coating matrix. However, a good suspension of nano-or micro-particles was always difficult to achieve due to the large surface area of the particles.…”

Corrosion behaviour in saline solution of pulsed‐electrodeposited zinc‐nickel‐ceria nanocomposite coatings

“…Corrosion potential of nanocomposite coatings are nobler than those of Zn‐Ni ones, which is in good agreement with the study of Katamipour et al The surface ennoblement can be due to a screening effect induced by ceria particles, which can block some defects of the coatings …”

“…The presence of the nanoparticles may affect the nature, distribution and density of the grain boundaries leading to modification of the metallurgical state as observed on the SEM pictures. [36,58]…”

“…Corrosion potential of nanocomposite coatings are nobler than those of Zn-Ni ones, which is in good agreement with the study of Katamipour et al [57] The surface ennoblement can be due to a screening effect induced by ceria particles, which can block some defects of the coatings. [58] Concerning the corrosion kinetics in the anodic domain, a slight modification after one hour of immersion is observed when particles are incorporated. This evolution is quite similar for both nanocomposite coatings meaning that the ceria particles dispersed onto the surface of the coating are responsible for this behaviour.…”