Electro-brush Plating Research Articles

Effect of pretreatment process on the performance of Ni-Co-Al2O3(sol) nanocomposite coatings via electro-brush plating on steel substrate

Effect of pretreatment process on the performance of Ni-Co-Al2O3(sol) nanocomposite coatings via electro-brush plating on steel substrate

Friction and wear mechanism analysis of the electro brush plating Ni-Mo alloy

The Ni-Mo coating as a replacement for hard chrome plating has gained popularity due to its low environmental pollution. This thesis aims to investigate the characteristics of a Ni-Mo alloy brush coating on a 45# steel base material using the brush plating process. The composition of the plating solution was varied to analyze the effects on the surface morphology, microstructure, hardness, and wear resistance of the Ni-Mo coating. The experimental results demonstrate that the surface morphology of the brush coating is significantly influenced by the composition of the plating solution. As the concentration of nickel sulfate and sodium molybdate varies, the coating exhibits a clear preferential growth tendency. Higher nickel sulfate concentration leads to the growth of coating grain along the (111) crystal plane, while higher sodium molybdate concentration encourages the growth of coating grain along the (220) crystal plane. Increased nickel sulfate concentration results in refined coating grains, while increased sodium molybdate concentration causes more distortion and dislocation of the coating layer. It was observed that the brush plating coating of Ni-Mo alloy, with a nickel sulfate concentration of 400–500 g/L and a sodium molybdate concentration of 25–30 g/L, exhibits not only good surface morphology but also higher micro-hardness and wear resistance. Overall, the analysis of the effects of plating composition on the characteristics of Ni-Mo coating is crucial in developing a high-quality and effective coating for industrial applications.

Electro-brush plating Ni-Graphene oxide composite coating enhanced corrosion resistance of fluoride ion

Ni-Graphene Oxide(GO) composite coating was prepared on Q235 steel plate by electro-brush plating technique to reduce the corrosion of fluoride ion. In this study, SEM, XRD and Raman tests were performed to analyze the morphologies and structures of the coatings, then electrochemical characterization was evaluated to determine the corrosion resistance. The results showed that GO provided more nucleation sites, and the surface of coatings looked more uniform and much denser because GO and Ni atoms were co-deposited on coating surface. The composite coating showed a better corrosion resistance than the pure nickel and there was an optimal addition amount of GO (Ni-GO/0.75 coating). In detail, the corrosion voltage increased from −0.61187 V to −0.52542 V, and the corrosion current correspondingly decreased from 26.6 μA·cm−2 to 6.8 μA·cm−2, correspondingly. The charge transfer resistance was also increased from 558.6 Ω to 1769.0 Ω. Moreover, the immersion testing demonstrated that the weight loss of Ni-GO/0.75 composite coating was only 22.2% of the pure nickel. In addition, XPS spectra indicated that the fluoride ions in the corrosive medium preferentially bonded with nickel atoms, preventing the medium from entering the active area. In conclusion, Ni-GO composite coating exhibited excellent corrosion resistance to fluoride ion due to the impermeability and high conductivity of GO.

Effect of Heat Treatment on Microstructure and Performance of Nano-WC Particle-Strengthened Ni Composite Coatings by Electrobrush Plating

Electrobrush plating technology has been widely used in surface remanufacturing and reinforcement and could be used to repair and reconstruct waste machinery and other products. In this paper, the effect of heat treatment on microstructure, wear resistance and thermal shock resistance of nano-WC particle-strengthened Ni composite electrobrush plating coatings was investigated using phase analysis, morphological observation, microhardness testing and coating lifetime evaluation. After heat treatment at 550°C, the cauliflower structure became more compact and the interface between coating and substrate was strengthened due to element diffusion, which led to an increase in the microhardness and coating lifetime. As the heating temperature increased, the microstructure of the coatings and substrate grew abnormally, which resulted in degradation of the coating properties. The extension of the thermal shock lifetime of the coatings after heat treatment contributed to microstructure improvement, element diffusion and new phase formation, which prolonged the times for crack initiation and propagation.

Preparation, deposited behavior and hydrophobic property of modified graphene oxide reinforced Ni composite coatings by magnetic field assisted electro-brush plating

Graphene oxide (GO) as nano reinforcement has been extensively used to improve the overall performance of metal-based composite coatings. In this work, GO nanosheets with surface modification and magnetic field (MF) assisted electro-brush plating (EBP) technique were employed to construct Ni-based composite coatings with biomimetic structure to improve the corrosion resistance of coatings. The preparation, deposited behavior and some properties of coatings were investigated. The results showed that after surface modification, GO surface carried numerous Co7Fe3 magnetic nanoparticles with the size of 40–50 nm. During the MF assisted EBP process, the co-deposition of CoFe@GO magnetic powders with the reduced Ni atoms contributed to the formation of Ni-CoFe@GO composite coatings with stripe-like structure that resembled the surface morphology of conch. Besides, induced by the synergistic action of MF and electric field, most magnetic powders were distributed regularly in the stripe-like areas. After two weeks exposure to air, Ni-CoFe@GO composite coatings changed spontaneously from hydrophilic for fresh coatings to hydrophobic. This transformation was mainly attributed to the high surface roughness and the adsorption of a lot of hydrocarbons on the stripe-like surface. Moreover, air pockets that resulted from these hydrocarbons formed on the coating surface impeded the diffusion of corrosive media into coatings. Consequently, Ni-CoFe@GO composite coatings exhibited good corrosion resistance. Therefore, the preparation proposed in this work is desirable and has a prospect in further improving the corrosion resistance of GO reinforced Ni-based composite coatings.

Microstructure and Properties of Cr-Fe2B Composite Coatings Prepared by Pack-Preboronizing Combined with Electro Brush-Plating

Cr-Fe2B composite coatings were prepared on carbon steels by pack-boronizing followed by electro brush-plating. The microstructure and properties of the coatings annealed at different temperatures were studied. The coatings show a gradient structure composed of a Cr-layer and a Fe2B-layer and have excellent thermal stability, and no new layers and/or transition layers are formed in the coating during annealing up to 1000 °C. The Cr-layer has an amorphous structure and is transformed into nanosized grains when the annealing temperature increases to 700 °C. As the annealing temperature is further increased, the nanograins grow rapidly. The microcracks in the Cr-layer increase sharply after annealing at 550 °C and then decrease significantly with any further increase of the annealing temperature. The pre-deposited Fe2B-layer prevents the formation of carbon-poor zones in the steel substrate during annealing. It is considered that high-temperature (>700 °C) annealing helps to eliminate coating defects, increase the coating density and obtain better wear resistance and corrosion resistance. Surprisingly, the as-plated and low temperature annealed samples also show good wear resistance and corrosion resistance, which may be related to their amorphous structure and nanocrystalline structure.

Comparison of MWCNTs and GO reinforced electro-brush plated Ni nanocomposite coatings: structural variations of carbon-based reinforcements and tribological behavior

Abstract As reinforcements, carbonaceous nanomaterials (CNMs) especially multi-walled carbon nanotubes (MWCNTs) and graphene oxide (GO), have attracted increasing attention in the application of electrodeposition. In this work, Ni-based nanocomposite coatings with MWCNTs and GO were prepared by electro-brush plating technique (EBP). The results showed that adding MWCNTs and adding GO both significantly improved the compactness of Ni coatings, however, the latter contributed more uniform microstructure and morphology of nanocomposite coatings owing to the excellent dispersion of GO. In addition, MWCNTs and GO could not only provide numerous nucleation sites for Ni primary crystals contributing the grain refinement, but also co-deposited with Ni atoms to form a strong interfacial bonding with Ni matrix. The addition of MWCNTs and GO can significantly reduce the worn volume of coatings from 7.52 × 107 μm3 to 3.49 × 107 μm3 and 2.82 × 107 μm3, respectively. Moreover, Ni nanocomposite coatings adding GO exhibited better wear resistance and friction stability than that of adding MWCNTs. Microstructural characterizations revealed that during wear testing, the agglomerated MWCNTs in nanocomposite coatings were destroyed severely and transformed into the shorten MWCNTs or the unfolded sidewalls, thereby leading to the instability of the wear process. In contrast, the damage degree of rGO was relatively slight. The nanosheets of rGO uniformly distributed in nanocomposite coatings became smaller and some of them were stacked between each other, which promoted the stability of friction process.

Parameter optimization and wear characteristics of nano CuO/Ni composite coating by brush plating technique

The development of deposition of different metal processes established on electrodeposition of nickel, different alloy and composite coatings on different surfaces has attested an upsurge in interest among researchers. In latter years, these coatings have exhibited promising corrosion and wear resistance properties. Also, huge number of modern developments became most critical from macro to nano level applications. It is well known that one may shape the microstructure and the phase present in the material to recover the mechanical properties of highly pure materials, specifically metals. Co-deposition of fine particles inside a metal matrix to generate composite coatings has treated as a practical strategy to acquire enhanced mechanical properties like wear resistance, corrosion resistance and lubrication. In this work, CuO/Ni composite coatings are processed on the small cylindrical pin by electro brush plating to evaluate the wear and corrosion resistance. To examine the effects about the different parameters of processes on wear loss of CuO/Ni composite coating, L16(44) orthogonal experiment is designed and conducted with four process parameters (voltage, concentration of nanoCuO particles in g/l, temperature and thickness) which are selected as factors. Design of experiment is employed to resolve the effects of process parameters on the wear loss of composite coatings. It is concluded that concentration of CuO nanoparticle and voltage are the most significant factors for the wear loss.

Microstructure, deposition mechanism and tribological performance of graphene oxide reinforced Fe composite coatings by electro-brush plating technique

Enhancement of mechanical performances is a challenging issue for Fe-based coatings prepared by electro-brush plating technique (EBP), and graphene oxide (GO) has been regarded as a promising additive currently. Thus, in this work, GO sheets were used to improve the microstructure and mechanical properties of electro-brush plated Fe coatings. The results showed that GO was reduced to the reduced graphene oxide (rGO) undergoing the electrochemical reduction, and the rGO sheets were co-deposited with those metal atoms during EBP. As expected, the defects number of Fe coatings was decreased obviously with the addition of GO, which is attributed to that the co-deposition process of GO with Fe atoms could facilitate the emission of hydrogen atoms away from the cathode, avoiding the formation of hydrogen-induced defects in coatings. In addition, the grains of Fe-GO composite coatings were remarkably refined as the rGO sheets provided heterogeneous nucleation sites for the primary Fe crystals. Improved micro-hardness and wear resistance were achieved after adding GO. Compared with Fe coatings, the average friction coefficient and weight loss of Fe-GO composite coatings were decreased by 49.5% and 39.7%, respectively, due to the effect of self-lubrication and reinforcement of rGO sheets.

Reduced friction and wear of electro-brush plated nickel composite coatings reinforced by graphene oxide

The nano-scale studies in the literature have revealed the excellent anti-friction properties of graphene and its great potential as a nano solid lubricant. However, for macro-scale applications the integrity and durability are main problems for most graphene-based surface coatings. One way to mediate the durability issue while exploiting the tribology of graphene is graphene-based composites. In this work, nickel-graphene oxide (GO) composite coatings were fabricated on steel by electro-brush plating. The effects of GO on the tribological properties were investigated. The results show that the composite coatings possess much lower friction than GO-free nickel coating (up to 47% less against a bearing steel ball, and 30% less against an alumina ball). As the GO load increases from 0 to 4 mg/ml, the wear rate of the resulting composite can be reduced significantly by approximately 90%. Detailed post-test studies of the wear tracks and the counterpart were conducted using SEM, EDS, Raman and FIB/SEM. The improved tribological properties can be attributed to the strengthening effect, the retention of oxide tribo-films and the formation of GO rolls during sliding. The tribological behaviour of the Ni-GO nano-composite coating and a Ni-graphite composite coating was compared, and their different wear mechanisms have been discussed.

Fabrication of Adhesive Resistance Surface with Low Wettability on Ti6Al4V Alloys by Electro-Brush Plating.

Anti-adhesive Ni coatings with low wettability were successfully fabricated on Ti6Al4V substrates via an electro-brush plating method, and subsequently modified with a fluoroalkylsilane (FAS) film. The surface morphology, chemical compositions, and wettability of the as-prepared coatings were measured using scanning electron microscopy (SEM), X-ray diffractometer (XRD), Fourier transform infrared spectrophotometry (FTIR), and contact angle measurements. The results showed that the surface of Ti6Al4V substrate was endowed with flower-like structures. Each flower-like cluster was constituted by a large number of Ni ions. After surface modification of FAS, the as-prepared Ti6Al4V surface had a water contact angle as high as 151.5°, a sliding angle close to 2.1°, and a solid surface energy as low as 0.97 mJ/m2. Potentiodynamic polarization tests showed that the Ni coating could provide a stable corrosion protection. In addition, the effects of processing conditions, such as working voltage, relative velocity, electrolyte concentration, and processing time, were investigated. The mechanism of the adhesive resistance was proposed, and the low wettability of Ti6Al4V surfaces was explained by Cassie–Baxter model. As a result, it was necessary to reduce the fraction of the solid–liquid interface in order to achieve anti-adhesive surface.

Two–step fabrication of superhydrophobic surfaces with anti–adhesion

A self–cleaning property with anti–adhesion and superhydrophobicity was fabricated on aluminum alloy surface via a facile and low–cost method coupling electro–brush plating and laser processing. The surface morphology, chemical composition, wettability, anti–adhesion and self–cleaning effect were analyzed by multiple ways. The results indicated that an array of micro–scale grooves and typical hierarchical protrusion structure were covered on the surface, and the edge of the groove was covered by micro–scale sputtering particles. The special composite structures played an important role in amplifying the hydrophobic property of surface. The surface showed excellent superhydrophobic properties. The contact angle was as high as 156.3° and the sliding angle was 4.8°. The water droplet has approached onto the superhydrophobic surface and completely bounced back to the tip of the needle on the coupling surface. The adhesion between the coupling surface and the water droplet is very weakly, the surface has excellent anti–adhesion property. Through the comparative test, the composite method also has excellent low adhesion property to the polyethylene material. In this case, the low adhesion led to a rolling and self–cleaning behavior. The approach presented in this study provides a facile, low–cost and efficient method to fabricate superhydrophobic surfaces on all types of metallic materials for commercial applications.

Study on Repairing Technologies and Repairing Experiment by Electro-Brush Plating of Camshaft

The surface failure of engine camshaft was introduced. The surface repairing technologies of failure camshaft such as thermal spraying, laser cladding and electro-brush plating were analyzed comparatively. The characteristics of the process of repairing camshaft by electro-brush plating technology were introduced. The effects of plating solutions of rapid nickel, Ni-Co, Ni-Wu and nano Al2O3/Ni on surface properties of camshaft coatings were experimentally studied. It is concluded that the electro-brush plating technology can be applied to repair failure camshafts due to simple equipment, fast repairing speed and high bonding strength between substrate and coatings. The surface morphology of the nano Al2O3/Ni coating is the most uniform and compact, and the hardness of the coating is higher than substrate’s. The hardness of the rapid nickel coating is the highest, but the coating surface morphology is relatively coarse and uneven. Nano particles have a significant refining effect on coatings. Using nano Al2O3/Ni electro-brush plating technology to repair surface failure camshaft can improve surface hardness and make it remanufactured and utilized.

Microstructure and Performance of Nano-WC Particle-Strengthened Ni Coatings by Electro-brush Plating

Nano-WC particle-strengthened Ni composite coatings were prepared by electro-brush plating. A series of artificial neural network models was developed for the analysis and prediction of the coating performance. The microstructure and phase structure were studied with SEM, XRD and EDS. Nano-WC particles as the hard phase were distributed evenly and dispersed in the coatings, which was conducive to the hardness enhancement of the coatings. Additionally, nano-WC particles as microballs inserted in the coatings could reduce the friction when wear of the coating surface occurred. Furthermore, the addition of nano-WC particles delayed the time of crack initiation and propagation in the coatings, which increased the service lifetime when they worked in a thermal shock environment.

Thermal stability of Ni-B/La2O3 coatings by electro-brush plating technique

The metastable materials have attracted the attention of researchers due to their promising physicochemical properties, but the thermal stability limits their practical application. In this paper, Ni-B/La2O3 amorphous/nanocrystalline composite coatings were prepared on AISI 1045 steel substrate by electro-brush plating technique. The surface morphology, component and the phase structure of coatings were observed by Scanning Electron Microscope (SEM), Energy Dispersive X-Ray Spectroscopy (EDS) and X-Ray Diffraction (XRD), respectively. The coatings were further analyzed by Transmission Electron Microscope (TEM). Then the thermal stability of coatings with different content of La2O3 was also analyzed under different annealing temperature. It was found that the coating had a unique microstructure consisting of amorphous and nanocrystalline structures. The addition of La2O3 does improve the thermal stability of metastable Ni-B coatings when the annealing temperature is over 355°C. In addition, the thermal stability of the amorphous/nanocrystalline coatings depends on the percentage of amorphous phase and grain sizes.

Microstructure and mechanical properties of electro-brush plated Fe/MWCNTs composite coatings

Fe/MWCNTs (multi walled carbon nanotubes) composite coatings with varying-content MWCNTs (0, 0.1, 0.2, 0.5 and 0.9 g/L) on the surface of AISI 1045 steel were produced by electro-brush plating technique. The effect of MWCNTs concentration in the plating solution on the microstructures and of the composite coatings was discussed in detail. The co-deposition of MWCNTs with Fe atom occurs in the Fe-based coating, which can decrease the number of through-wall cracks and increase the deposition velocity whereas the phase structure of the composite coatings cannot be affected. When the content of MWCNTs added in the plating solution is 0.2 g/L, the microhardness (612 HV0.3) of coating is much higher than that of pure Fe coating (489 HV0.3). The friction coefficient and weight loss of all Fe/MWCNTs composite coatings are significantly lower than that of pure Fe coating, which is attributed to the effect of reinforcement and lubrication of MWCNTs.

Effect of Annealing Treatment on Microstructure and Properties of Cr-Coatings Deposited on AISI 5140 Steel by Brush-Plating

Cr-coating was deposited on AISI 5140 steel by electro brush-plating, followed by annealing treatment at different temperatures, from 300 to 1100 °C. The microstructure evolution of the Cr-coating was characterized by backscattered electron imaging (BSEI) and energy dispersive spectrometry (EDS). The results show that the brush-plated sample has a nodular shaped microstructure, which is very stable at 300 °C of annealing. At 500 °C of annealing, the constitution of the microstructure changes from nodules to grains. As the annealing temperature further increases, the grains grow significantly. When the temperature reaches 1100 °C, a Cr-Fe solid-solution layer is formed within the original pure Cr-coatings. With increasing annealing temperature, the number of micro-cracks in the coating increases first and then decreases, reaching a maximum at 500 °C. The hardness and wear-resistance of the coating are improved when the annealing temperature increases to 1100 °C, owing to the decrease of micro-cracks that formed during brush-plating.

Wear Resistance Properties Reinforcement Using Nano-Al/Cu Composite Coating in Sliding Bearing Maintenance.

Sliding bearing maintenance is crucial for reducing the cost and extending the service life. An efficient and practical solution is to coat a restorative agent onto the worn/damaged bearings. Traditional pure-copper (Cu) coating results in a soft surface and poor abrasion resistance. To address this issue, this paper presents a nano-composite repairing coating method. A series of nano-Al/Cu coatings were prepared on the surface of 45 steel by composite electro-brush plating (EBP). Their micro-hardness was examined by a MHV-2000 Vickers hardness tester, and tribological properties by a UMT-2M Micro-friction tester, 3D profiler and SEM. Then, the influence of processing parameters such as nano-particle concentration and coating thickness on the micro-hardness of nano-Al/Cu coating was analyzed. The experimental analysis results demonstrate that, when the nano-Al particle concentration in electrolyte was 10 g/L, the micro-hardness of the composite coating was 1.1 times as much as that of pure-Cu coating. When the Al nano-particle concentration in electrolyte was 20 g/L, the micro-hardness of the composite coating reached its maximum value (i.e., 231.6 HV). Compared with the pure-Cu coating, the hardness and wear resistance of the nano-composite coating were increased, and the friction coefficient and wear volume were decreased, because of the grain strengthening and dispersion strengthening. The development in this work may provide a feasible and effective nano-composite EBP method for sliding bearing repair.

Fabrication and characterisation of electro-brush plated nickel-graphene oxide nano-composite coatings

The extraordinary mechanical and anti-corrosion properties of graphene call for facile fabrication of graphene-based coatings with high uniformity and in large area. This research was aimed at exploring the use of an electro-brush plating technique for the production of graphene-metal nano-composite coatings. Graphene oxide (GO) was introduced into the nickel plating solution at varied concentrations and composite coatings were fabricated on stainless steel surfaces by brush plating under the same conditions. The morphology and microstructure of the obtained Ni-GO composite coatings were fully characterised and compared with neat Ni coating. The results confirm that GO sheets have been incorporated into the nickel matrix homogeneously, leading to a considerably reduced average crystallite size. Nanoindentation measurements demonstrated that GO can not only improve the hardness and reduce the plasticity of the composite matrix, but also enhance the thermal stability of the composite coating effectively. It has also been revealed by polarisation and electrochemical impedance spectroscopy (EIS) analysis that GO can increase the corrosion resistance of the composite coating owing to its barrier effect. However, it was also noticed that excessive GO content resulted in a degradation of both mechanical and corrosion properties, likely due to a more defective microstructure.

Fabricated composite structure with hydrophobicity and anti-corrosion by sandblasting and electro-brush plating

The micro-nano composite structure on carbon steel substrate can be fabricated, and the composite structure not only has the property of hydrophobicity, but also has the property of corrosion resistance, which can be fabricated by combining a sandblasting technology and electro-brush plating method. The micro-nano composite structure fabricated by combining methods have been studied by the different preparation technology parameters, and then the different surface morphologies were obtained, at the same time, the different micro surface structures were formed. The parameters of the brush plating voltage plays an important part in this preparation process, so we can select the best parameters by changing the parameters of the brush plating voltage during the preparation process, and after the preparation process, hydrophobic surface has a bigger static contact angle than before, which is up to 149.3°±2.5° without any modification. In this paper, the qualitative and quantitative ananlysis of various properties of the fabricated surface with the composite structure were studied by advanced techniques. The hydrophobic surface morphologies were investigated by means of scanning electron microscope (SEM), and the wettability of the surface were investigated by water contact angle measurements (WCA), the corrosion resistance of the fabricated surface on carbon steel substrate was investigated by potentiodynamic measurements. Through the above analysis, we can get a lot of corresponding results, and the results what we get showed that the micro-nano composite structure that constructed on the surface of carbon steel not only has the property of hydrophobic on the surface, and the hydrophobic surface also has the property of corrosion resistance by combining the technology of sand blasting and electro-brush plating. Moreover, based on potentiodynamic polarization measurement in 3.5 wt% NaCl solution, the average corrosion current density of the sample surface that was fabricated by combining methods on carbon steel substrate is decreased by 1–2 orders of magnitude, and which is also less 1–2 orders of magnitude than the bare carbon steel, and because of that, the corrosion rate is also decreased, and the corrosion electric potential has an ascending tendency because of the average corrosion current density decreased. So its corrosion resistance is improved after this preparation process. It is seen that, through the method that design of combining sandblasting technology and electro-brush plating method constructed on the surface of carbon steel, the micro-nano composite structure was obtained excellent properties which included hydrophobic and corrosion resistance.