NiP/SiC composite coatings: the effects of particles on the electrochemical behaviour (original) (raw)
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Materials Research Express, 2021
Fabrication of NiP-SiC nanocomposite coatings through the electroless deposition in a commercial electrolyte containing the low concentrations of SiC nanoparticles on carbon steel substrate was studied in this work. The confirmation of co-deposition of Ni matrix and SiC nanoparticles was investigated by evaluating the effect on morphology, crystal structure, and corrosion behavior of the heat-treated coatings which were investigated by scanning electron microscope, x-ray diffraction (XRD), and electrochemical measurements, respectively. The XRD results revealed that the heat-treated NiP and NiP-SiC coatings consisted of Ni and Ni3P phases, which the calculated faction of Ni3P phase for NiP and NiP-SiC samples is 58.2 and 62.2%, respectively. The corrosion resistance of nanocomposite samples is higher than that of pure NiP sample (9 to 76% corrosion inhibition efficiency. The tribological behavior of the coatings was characterized by microhardness measurement and ‘pin on disk’ wear t...
Journal of Materials Engineering and Performance, 2015
The addition of silicon carbide (SiC) nanoparticles into electroless nickel (Ni)-based coatings improves both corrosion resistance and mechanical properties of the resulting Ni-P/SiC nanocomposite coatings, making them potential candidate as protective coatings in aggressive environments. Ni-P/SiC nanocomposite coatings were produced from precursor bath with small SiC loading levels (0.25 or 1.0 g/L) and characterized for morphology, corrosion resistance, and hardness. Microstructural examination using FE-SEM and AFM revealed that incorporation of uniformly dispersed SiC nanoparticles leads to smaller nodule size with fine-grain structure and low surface roughness. Electrochemical impedance spectroscopy studies in 4 wt.% NaCl solution showed that the nanocomposite coatings exhibit excellent corrosion resistance, as indicated by high charge-transfer resistance and low double-layer capacitance values of $137 kX cm 2 and 19 lF cm 22 , respectively. The coatings maintained their structural integrity even after 5 days of saline bath immersion, as there was no cracking in the deposit microstructure besides formation of shallow pits and submicron-sized pores. A twofold increase in the average hardness value was noticed from 4.5 (pure NiP) to 8.5 GPa (Ni-P/SiC coating) which can be ascribed to modified deposit morphology and uniformly dispersed SiC nanoparticles that act as obstacles to plastic deformation.
STRUCTURE AND WEAR RESISTANCE PROPERTIES OF ELECTROLESS Ni-P ALLOY AND Ni-P-SiC COMPOSITE COATINGS
European Chemical Bulletin, 2013
To verify the relationship between the properties of composite coatings prepared on steel and the SiC content of electroless Ni-P-SiC composite coatings. Systematic experiments have been conducted to study the possibility of incorporating solid SiC particles in Ni-P matrix. Kinetics of Ni-P plating reveal that the rate of deposition was found to increase linearly with time. The reduction process of nickel ions by hypophosphite was completely hindered at pH < 2and the minimum temperature at which the bath can be practically operated was about 65 ˚C. The mode of deposition of Ni-P film has been explored in the light of deposition condition. XRD analysis of the as-plated and heat -treated samples revealed the existence of crystalline Ni 3 P phases for the heat -treated alloy. Finally a component electroless Ni-P-SiC composite plating process producing a high wear resistance of the coating. *Corresponding Authors *
Coatings
In this study, electrodeposition of NiP composite coatings with the addition of SiC 100 nm was carried out on low carbon steel studying the effect of additives (sodium dodecyl sulfate, saccharin), particles load (10 or 20 g/L) and current density (1, 2 and 4 A/dm2). As a benchmark, coatings from an additive-free bath were also deposited, despite additives being essential for a good quality of the coatings. The coating’s morphology and composition were evaluated by scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS). It was shown that by addition of sodium dodecyl sulfate (SDS), pure NiP coating with a higher P content was achieved, and their morphology changed to nodular. SDS also reduced the codeposited fraction of SiC particles, while saccharin increased it. SiC loading and current density had less impact respect to the additives on codeposition of SiC particles. Finally, the microhardness of NiP coatings did not increase linearly by codeposition ...
Electrodeposition and Mechanical Characterization of Ni/SiC Composite Coatings
Journal of Nano- and Electronic Physics, 2019
The need to improve coatings for better properties leads to the development of composite electrolytic deposition, by adding insoluble solid particles to the electrolyte. These coatings typically contain ceramic particles in an electrodeposited matrix such as nickel. The aim of this work is to obtain an electrolytic nickel matrix (binder) with and without adding silicon carbide SiC microparticles (mean diameter 0.8 m) which have a high hardness and a good chemical stability. The structural (Ni-SiC) composite and pure nickel coatings were prepared by electroplating deposition on steel in a Watts bath of electroplating chloride. The surface morphology, microstructure, and composition were studied by atomic force microscopy (AFM), nanoindentation, scanning electron microscopy (SEM) and X-ray diffractometer. The characterizations of the deposited layers are carried out in 3.5 % NaCl solution. The weight loss and the polarization results highlighted that the corrosion rate decreases with the increase of SiC concentration up to 15 gl-1. This decrease is probably due to the presence of SiC particles leading to improved corrosion resistance. These properties are mainly due to the homogeneous distribution of the constituents SiC as determined by AFM technique and the possibilities of combining the characteristics of base metals and their coatings. Moreover, the incorporation of the microparticles had a significant impact on the microhardness of the composite deposits Ni-SiC.
ELECTROCHEMICAL CORROSION PROPERTIES OF SiC / Ni NANOCOMPOSITE COATINGS IN 0 . 5 M NaCl
Nano particles have an influence on nickel electrocrystallisation steps: decreasing charge transfer resistance and activating the nickel reduction. The SEM – EDX surface morphology and TEM structure of the electrodeposited nanocomposite were investigated. The dispersed particles perturb the nickel crystal growth resulting in a random rather than in a preferred orientation. The corrosion behaviour of the nano-composite coatings was evaluated in the solution of 0.5M NaCl at room temperature. It was found that the polarization resistances of nanoSiC–nickel composite coatings are higher compared pure nickel coatings. The SiC distribution in the nano-composite coatings at low concentrations of SiC in bath was uniform across the coatings. The incorporation of the SiC nano-particles leads to the changes in the morphology and corrosion resistance of the nano-composite coatings as compared to the pure nickel coatings. The Ni–SiC nano-composite coatings have higher corrosion resistance than t...
MECHANICAL PROPERTIES CORRELATED TO STRUCTURE FOR NiP / SiC COMPOSITE SURFACE COATINGS
2010
A complex research has been undertaken to obtain and investigate Ni-P/SiC surface coatings on mild steel and on pure Cu, electroplated from an electrolyte having various amounts of micron size SiC particles in suspension (0-80g/litre SiC) and various amounts of the electrochemically active component H3PO3 in the electrolyte (0-20g/litre H3PO3). Ni based solid solutions supersaturated in P have been obtained in the metallic matrix of the composite coating whose P content was increased in steps (0; 8.4; 16.1; 20at.%P). Two types of heat treatments have been applied to the Ni-P/SiC electroplated coatings, either a dehydrogenating annealing at 190C or a precipitation aging treatment at 420C whose structural effects were investigated by microscopy and X-ray diffraction examination. Various properties have been investigated in non heat treated and in heat treated condition: uniformity of coating thickness and adherence, friction coefficient, Vickers penetration hardness. A special attenti...