scholarly journals Effect of Current Density on the Performance of Ni–P–ZrO2–CeO2 Composite Coatings Prepared by Jet-Electrodeposition

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 616
Author(s):  
Zhaoyang Song ◽  
Hongwen Zhang ◽  
Xiuqing Fu ◽  
Jinran Lin ◽  
Moqi Shen ◽  
...  

The objective of this study was to improve the surface properties, hardness, wear resistance and electrochemical corrosion resistance of #45 steel. To this end, Ni–P–ZrO2–CeO2 composite coatings were prepared on the surface of #45 steel using the jet-electrodeposition technique by varying the current density from 20 to 60 A/dm2. The effect of current density on the performance of the composite coatings was evaluated. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) were applied to explore the surface topography, elemental composition, hardness and electrochemical corrosion resistance of the composite coatings. The results showed that with the increase in the current density, the hardness, wear resistance, and electrochemical corrosion resistance tends to increase first and then decrease. At a current density of 40 A/dm2, the hardness reached a maximum of 688.9 HV0.1, the corrosion current reached a minimum of 8.2501 × 10−5 A·cm−2, and the corrosion potential reached a maximum of −0.45957 V. At these values, the performance of the composite coatings was optimal.

2015 ◽  
Vol 228 ◽  
pp. 305-309
Author(s):  
Magdalena Popczyk ◽  
Bożena Łosiewicz ◽  
Eugeniusz Łągiewka ◽  
A. Budniok

The Ni+W+Mo+Si composite coatings were prepared by electrodeposition under the galvanostatic conditions (jdep= -100 mA cm-2) from the nickel bath containing powders of tungsten, molybdenum and silicon. Thermal treatment of the obtained coatings was conducted in argon atmosphere. Chemical composition of the coatings was determined by energy dispersive spectrocopy (EDS). Phase composition investigations were conducted by X-ray diffraction (XRD) method. Studies of electrochemical corrosion resistance were carried out in 5 M KOH solution. On the basis of these investigations it was found that Ni+W+Mo+Si thermally treated coating is more corrosion resistant than Ni+W+Mo+Si as-deposited coating.


2016 ◽  
Vol 23 (01) ◽  
pp. 1550082 ◽  
Author(s):  
PRASANNA GADHARI ◽  
PRASANTA SAHOO

The present study investigates the effect of titania particles on the micro-hardness, wear resistance, corrosion resistance and friction of electroless Ni–P–TiO2 composite coatings deposited on mild steel substrates at different annealing temperatures. The experimental results confirmed that the amount of TiO2 particles incorporated in the coatings increases with increase in the concentration of particles in the electroless bath. In presence of TiO2 particles, hardness, wear resistance and corrosion resistance of the coating improve significantly. At higher annealing temperature, wear resistance increases due to formation of hard Ni3P phase and incorporation of titania particles in the coated layer. Charge transfer resistance and corrosion current density of the coatings reduce with an increase in TiO2 particles, whereas corrosion potential increases. Microstructure changes and composition of the composite coating due to heat treatment are studied with the help of scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDXA) and X-ray diffraction (XRD) analysis.


2010 ◽  
Vol 636-637 ◽  
pp. 1042-1046
Author(s):  
Magdalena Popczyk ◽  
Antoni Budniok

Zn-Ni and Zn-Ni-W coatings were prepared by the electrodeposition under the galvanostatic conditions (jdep. = -0.020 A cm-2) from the zinc bath containing additionally ions of nickel (Zn-Ni) and ions of nickel and tungsten (Zn-Ni-W). The Zn-Ni coating after electrodeposition was subjected to outside passivation and in the Zn-Ni-W coating the passive function performs tungsten (inside passivation). The surface morphology of the coatings was studied using a scanning electron microscope (JEOL JSM - 6480). Chemical composition of obtained coatings was determined by the X-ray fluorescence spectroscopy (XRF). Phase composition investigations were conducted by X-ray diffraction method using a Philips diffractometer. Electrochemical corrosion resistance investigations were carried out in the 3% NaCl, using potentiodynamic and electrochemical impedance spectroscopy (EIS) methods. On the basis of these investigations it was found that Zn-Ni coating is more corrosion resistant than the Zn-Ni-W coating.


2015 ◽  
Vol 1090 ◽  
pp. 79-83
Author(s):  
Yan Hong He ◽  
Zhen Duo Cui ◽  
Xian Jin Yang ◽  
Sheng Li Zhu ◽  
Zhao Yang Li ◽  
...  

In this paper, Pd ions doped cerium conversion coating (CeCC/Pd) was deposited on AA2219-T87 aluminum alloy by electroplating. The microstructure and composition of the coating were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS). Corrosion behavior of AA2219-T87 aluminum alloy with the coating was investigated in 3.5wt.% NaCl solution at the room temperature. XRD and XPS results indicate the existence of cerium-oxide and palladium-oxide in the CeCC/Pd. Polarization curves show that the CeCC/Pd exhibits excellent corrosion resistance. The corrosion current density of the CeCC/Pd decreases by two orders of magnitude compared with the CeCC. The improvement of corrosion resistance would be attributed to the small grain size, good compactness and adhesive strength of the composite coatings.


2015 ◽  
Vol 228 ◽  
pp. 231-236 ◽  
Author(s):  
Magdalena Popczyk ◽  
B. Łosiewicz ◽  
Eugeniusz Łągiewka ◽  
A. Budniok

The Ni+Mo composite coatings were prepared by electrodeposition under the galvanostatic conditions (jdep= -300 mA cm-2) from the nickel bath containing molybdenum powders of different granulation (3-7 μm, <150 μm, <100 nm). Thermal treatment of the obtained coatings was conducted in the argon atmosphere. The surface morphology of the coatings was studied using a scanning electron microscopy (SEM). Chemical composition of the electrodeposits was determined by X-ray fluorescence spectroscopy (XRF). Phase composition investigations were conducted by X-ray diffraction (XRD) method. Investigations of hydrogen evolution reaction (HER) and electrochemical corrosion resistance were carried out in 5 M KOH solution. It was found that for the Ni+Mo thermally treated coatings the decrease in activity towards the HER was observed. Simultaneously these coatings are more corrosion resistant than Ni+Mo as-deposited coatings. The reasons for the electrochemical properties of these coatings have been discussed.


2020 ◽  
Author(s):  
Renjie Ji ◽  
Hui Jin ◽  
Yonghong Liu ◽  
Tiancong Dong ◽  
Fan Zhang ◽  
...  

Abstract This paper reports a phenomenon that the grain orientation gradually evolves to (220) with the deposition current density increasing when preparing nanoparticles reinforced nickel-based composite coatings by jet electrodeposition (JED). During the preparation of Ni-SiC composite coatings, the deposition current density increases from 180 A/dm2 to 220 A/dm2, and TC(220) gradually increases from 41.4% to 97.7% correspondingly.The Ni-SiC composite coating with highly preferred (220) orientation has superior corrosion resistance and adhesion force. With the increase of TC(220), the surface roughness is reduced from Ra1.210 μm to Ra0.119 μm, the self-corrosion potential increases from -0.747 V to -0.477 V, the corrosion current density decreases from 54.52 μA·cm2 to 2.76 μA·cm2, the diameter of corrosion pits that after 10 days of immersion in 3.5 wt% NaCl solution decreases from 3.3~22.2 μm to 153~260 nm, and the adhesion of the coating is increased from 20.5 N to 61.6 N.The research results can provide theoretical and technical support for the preparation of new composite coatings with high efficiency, low cost, high adhesion and strong corrosion resistance.


DYNA ◽  
2018 ◽  
Vol 85 (207) ◽  
pp. 192-197 ◽  
Author(s):  
Estrella Natali Borja-Goyeneche ◽  
Jhon Jairo Olaya-Florez

This work researches the influence of the nickel content on the structural and anticorrosive properties of ZrSiTiN films deposited by means of reactive co-sputtering on alloys of Ti6Al4V. The morphology and structure were analyzed by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD), and the chemical composition was identified via X-ray scattering spectroscopy (EDS). The corrosion resistance was studied using potentiodynamic polarization (PP) tests employing a 3.5% by weight NaCl solution. In the films, an increase of Ni up to 6.97 at% was observed, while in XRD the FCC phase of (Zr, Ti) N was identified, with a mixed orientation in planes (111) and (200), which tended to diminish with the increase of Ni. Finally, with the addition of Ni, the corrosion current densities were reduced from 5.56 𝑥 10−8 to 2.64 𝑥 10−9 𝐴/𝑐m2. The improvement in the corrosion resistance is due to the effect of the Ni on the microstructure of the system (Zr, Ti) N, which can improve the quality of the passive film and prevent crystalline defects and corrosion zones.


2020 ◽  
Vol 67 (2) ◽  
pp. 150-157
Author(s):  
Kong Dejun ◽  
Li Jiahong

Purpose The purpose of this paper is to evaluate the salt spray corrosion (SSC) and electrochemical corrosion performances of CrNi, TiAlN/NiCr and CrNi–Al2O3–TiO2 coatings on H13 steel, which improved the corrosion resistance of H13 hot work mold. Design/methodology/approach CrNi, TiAlN/NiCr and CrNi–Al2O3–TiO2 coatings were fabricated on H13 hot work mold steel using a laser cladding and cathodic arc ion plating. The SSC and electrochemical performances of obtained coatings were investigated using a corrosion test chamber and electrochemical workstation, respectively. The corrosion morphologies, microstructure and phases were analyzed using an electron scanning microscope, optical microscope and X-ray diffraction, respectively, and the mechanisms of corrosion resistance were also discussed. Findings The CrNi coating is penetrated by corrosion media, producing the oxide of Fe3O4 on the coating surface; and the TiAlN coating is corroded to enter into the CrNi coating, forming the oxides of TiO and NiO, the mechanism is pitting corrosion, whereas the CrNi–Al2O3–TiO2 coating is not penetrated, with no oxides, showing the highest SSC resistance among the three kinds of coatings. The corrosion potential of CrNi coating, TiAlN/CrNi and CrNi–Al2O3–TiO2 coatings was –0.444, –0.481 and –0.334 V, respectively, and the corresponding polarization resistances were 3,074, 2,425 and 86,648 cm2, respectively. The electrochemical corrosion resistance of CrNi–Al2O3–TiO2 coating is the highest, which is enhanced by the additions of Al2O3 and TiO2. Originality/value The CrNi, TiAlN/CrNi and CrNi–Al2O3–TiO2 coatings on H13 hot work mold were firstly evaluated by the SSC and electrochemical performances.


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