Electroless Coating Research Articles

Improved EMI Shielding Behavior of Barium Ferrite Coated Carbon Fibers in Low‐Density Polyethylene Composites with an Optimized Electroless Coating Process

AbstractThis study describes using carbon fibers coated with magnetic material as a filler in polyethylene for EMI shielding. It investigates how to utilize barium ferrite (BaFeO3) as a conducting filler in a polyethylene matrix by optimizing the conditions for its electroless deposition onto carbon fibers. Various polymer nanocomposite samples were prepared using varying concentrations of BFO@CF. Scanning electron microscopy is used to assess the surface appearance of the composite and the distribution of BFO@CF within the polymer matrix. Including MWCNT/graphene nanoplatelets exhibit superior shielding properties, and the polymer composite with the BFO@CF demonstrates enhanced mechanical properties. The 8.2 to 12.4 GHz frequency range is used to study the EMI shielding properties. For the composition ratio of LDPE: MWCNT: GNP: BFO@CF (50 : 5 : 47.5 : 2.5), a maximum shielding of 67 dB was attained. After BFO@CF was added to the matrix, the absorption mechanism rather than the reflection mechanism dominated the shielding mechanism. A thorough evaluation and discussion of the shielding mechanism and parameters are presented.

Tribological Behavior of Ni-P Electroless Coating of Inconel 625 with Multiwall Nano Carbon Tubes

An attempt was taken to study the wear rate of coated Inconel 625 using 0.3 gm of multiwall carbon tubes (MWCNT).The coating was carried out by the Ni-P electroless coating method. The Ni-P-MWCNT coating was prepared by using nickel phosphorous solution. The sliding wear test was conducted using pin on discs tribometer. The wear rate behavior was investigated at various levels of pin on discs tribometer factors, and a predictive model was developed using regression equations. The wear test experiment was carried out based on the L27 orthogonal array. The wear process parameters load, sliding velocity, and sliding distance were chosen. It was observed that the rate of wear increased as the load increases, whereas increase in sliding velocity and sliding distance reduces the rate of wear. The developed regression model was validated with the measured wear rate. The percentage error was observed within 0.99%.

The Effect of Heat Treatment on Wear Properties of Ni-B-CNT Electroless Coating with Different Carbon Nanotube Concentration on AISI 4340 Steel

Study wear resistance for heat treatment of Ni-B-CNT electroless coatings. Different concentrations for CNT (0 ,0.35 and 0.7 g/l Ni-B-CNT composite coatings deposition on 4340 steel. After the procedure of coating, all samples were heat treatment. The test wear of a coating was valued with pin on disk technique. Preparation of Ni–B–CNT electroless coatings are with using nickel chloride in alkaline bath, borohydride and Multi walled carbon nanotubes. characterization with FESEM, micro hardness, XRD and surface roughness. Study for surfaces of worn with EDS and FESEM. Micro hardness results are show that the larger hardness1010 HV is gained by heat treatment for coating (Ni-B- 0.35 g/L CNT) because of concentration CNT caused structure conversion for coating Ni-B from amorphous to crystalline. Also, CNT prevent maximum heat production and decrease of the friction coefficient during test wear. CNT aggregation was noted result the presence for more particles (Ni-B - 0.7g/l CNT) that occur create roughness and also lead to increase in rate of wear because of big particles with weakly joined in matrix of Ni.

Evaluating the Effect of Laser Surface Modification on the Corrosion Behavior of Ni-P-SiC Electroless Coating Deposited on Al356 Alloy

Regarding their higher wear/corrosion resistance than conventional coatings, nickelphosphorus based composite coatings can reduce components’ costs and degradation. This study employed laser surface modification of Ni-P-SiC electroless coatings deposited on Al356 substrate, followed by investigating their microstructural changes and corrosion behavior. The results showed that increasing the laser power increases surface defects and causes substrate diffusion to the coating, which significantly reduces the corrosion resistance of the coating. In contrast, low-power laser operations can improve the corrosion resistance of Ni-P-SiC composite coatings by creating stable nickel phosphide phases, more uniform element distribution, and enhanced SiC particle-substrate coherence. All these factors increase the wear and corrosion resistance simultaneously.

Microstructural Evaluation of Graphene-Reinforced Nickel Matrix Ni-P-Gr Coating on Ti-6Al-4V Alloy by the Electroless Coating Method

Titanium alloys are widely used in many industrial applications, from aerospace to automotive, and from defense to medical, as they combine superior properties such as high strength and low density. Still, titanium and its alloys are insufficient in environments with friction and wear because of their weak tribological properties. In the literature, numerous research works on improving the surface quality of titanium alloys have been conducted. Electroless coatings, on the other hand, are one of the most widely used surface improvement methods due to its homogeneous thickness achievement, high hardness, and good corrosion resistance. The autocatalytic reduction in the coating process enhances the surface quality of the material or alloy considerably. In addition, many studies in the literature aim to carry the properties of electroless coatings to a higher point by creating a composite coating with the addition of extra particles. In this study, graphene-reinforced nickel matrix Ni-P-Gr coating was applied to the surface of Ti-6Al-4V alloy, in order to enhance weak tribological behaviors, by the electroless coating method. Moreover, the coated and uncoated, heat-treated, and non-heat-treated specimens were subjected to abrasion in linear reciprocating ball-on-plate configuration to observe tribological properties. Microstructure examination of the samples was performed using a scanning Electron Microscope (SEM), X-ray Diffractometer (XRD), X-ray Photon Spectrometry (XPS), and Raman Spectroscopy. Specific wear rates of specimens were calculated using microstructural analysis and the hardness of the produced samples was measured using the Vickers hardness test. Results indicate that both the coating and the heat treatment improved the microstructure and tribological properties significantly. With the graphene-reinforced Ni-P coating via electroless coating process, the hardness of the substrate increased by about 34%, while it increased by approximately 73% using subjected heat treatment. Furthermore, the wear rate of the Ti-6Al-4V substrate was approximately 98% higher than that of the heat-treated nanocomposite coating. The highest wear resistance was obtained at the heat-treated nanocomposite coating.

A Comparison between the Effect of Heat Treatment and Plasma on the Wear Activities and Corrosion Resistance of Ni-B Electroless Coating with AISI 4340 Steel

The study the hardness, wear corrosion resistance of as-coating, heat treatment and plasma-nitriding of Ni- B electroless coatings was deposit on 4340 steel. After the procees of coating, samples were plasma-nitriding in percentage hydrogen/nitrogen ratio (50%), in the temperature 400°C, at 4 hours were compared with heat treatment. characterization by of FESEM, XRD, microhardness, Corrosion Resistance and surface roughness measurements. Microhardness was show highest hardness of 1050 HV was obtained for Ni-B plasma-nitriding formula whereas the greatest hardness of 800 HV was become for sample of Ni-B heat treated. Ni-B coating is used in the enhancement of properties of the corrosion of AISI 4340 steel is due to the thickness of electroless deposition, which is uniform, and the cold of Ni-B coating to act as an active barrier between corrosion media and metal, it should be noted that the value of Ecorr is less negative and the rate of corrosion and Icorr is lower on the plated sample than on the uncoated sample. The rate of the wear for samples is decrement by plasma-nitriding with deposition time at (4h) and the temperature 400°C. Rate of wear for the materials depends not just into condition of wear test, but also with several properties of material and features as topography, hardness and friction coefficient.

Effect of the Plating Time on Nickel Electroless Coating Properties Deposited on the Super Duplex Stainless Steel UNS S 32750

Effect of the Plating Time on Nickel Electroless Coating Properties Deposited on the Super Duplex Stainless Steel UNS S 32750

Effect of Heat Treatment and Applied Load on Mechanical and Tribological Properties of Ni-B-CeO2 Composite Electroless Coating

Cerium oxide (CeO2) particle reinforced Ni-B composite coating was produced by electroless coating method from a Ni-B coating bath containing CeO2 particles. In the electroless plating bath, nickel sulfate hexahydrate ((NiSO4.6H2O) was used as nickel source, dimethylamine borane ((CH3)2NHBH3) as reducing agent, thiourea (CH4N2S) as stabilizer and sodium acetate (CH3COONa) as complexing agent. The aim of the study is to investigate the structural characterization of CeO2 particle reinforced coating and the effects of wear test conditions on its tribological properties. The surface morphology of the coating was performed by scanning electron microscope (SEM), and phase structure analysis was performed by X-ray diffraction (XRD). Nanohardness measurements were carried out with a nanoindenter device, and wear tests were done with a ball-on-disk test device. Worn surface analyzes were made using a 3D profilometer. Experimental results showed that the hardness of the coating increased with heat treatment; however, its tribological behavior changed depending on different loads

The Effect of Mechanical Properties on the Ultrasonic Velocity Of Ceramic Based Composites Fabricated By Electroless Coating Technique

The scope of the present study is to investigate the change of ultrasonic velocity with the physical and mechanical properties of Ni-Ti-WC composites. Since the materials used in the aerospace and automotive industries are exposed to high temperatures, friction and high stresses, the need for metal matrix composite materials used in manufacturing applications such as cutting discs and inserts has increased rapidly. Ni-Ti metal matrix composites reinforced with WC were circularly shaped in uniaxial hydraulic press. A mixture of 30% Ni, 2% Ti and 68% WC powders was sintered at 1000°C-1400°C with argon atmosphere in a tube furnace and were fabricated by electroless plating technique. XRD (X-Ray diffraction, SEM (Scanning Electron Microscope), compressive testing, hardness and ultrasonic velocity measurements were employed to investigated the mechanical and physical properties of specimens. Experimental results showed that ultrasound velocity values increased polynomial linearly with increasing sintering temperature. In addition, the fact that the highest sintering temperature resulted in 429.1HV hardness at 1400°C is an indication that the structure has become more robust and compact. The change in ultrasonic velocities with increasing sintering temperature is evidence of a better bonding of the structure.

ZrO2–CeO2 assimilated electroless Ni–P anti-corrosion coatings

ZrO2–CeO2 nanocomposites are well known for their superior mechanical, thermal and tribological properties. On the other hand, Ni–P electroless coatings are in widespread industrial usage. In this work, we attempted to assimilate the lab-made ZrO2–CeO2 nanocomposite into Ni–P electroless coating to achieve synergistic property enhancement through composition optimization. Several techniques thoroughly characterized both the as-prepared nanocomposite powder and the Ni–P–ZrO2–CeO2 composite coating. The results proved that the nanocomposite assimilation refined coating surface morphology and boosted mechanical, tribological and corrosion resistance properties. Post-high-temperature annealing at 350 °C, significantly improved the coating performance, which was attributed to the annealing induced morphology refinement and crystallization.

Experimental study of quenching agents on Al6061–Al2O3 composite: Effects of quenching treatment to microstructure and hardness characteristics

Aluminium based composite or well known as Aluminium Matrix Composites (AMC) can be improved in terms of mechanical properties with heat treatment. The quenching process parameters such as cooling rate, cooling agent and cooling temperature are predicted to affect the mechanical properties of the AMC. This study presents the results of a series of laboratory experiment to observe hardness ability of the Al6061–Al2O3 composites subjected to quenching agent and particle surface treatment. There are 3 variations of quenching agent and 2 types of reinforcement particle treatment. The quenching agent using water, oil, salt solution (brine), and 0% and 10% weight fraction of Al2O3 reinforcement. The hardness testing is conducted to the Rockwell B scale according to regulation of ASTM E−18. Obtained results indicated that the biggest distortion occurred as influences of quenching brine agent on each variation. The hardness of the 10E specimens (with treatment of Electroless Coating) is higher than the 10 N specimens (with treatment of Non-Electroless Coating). Based on this finding, it can be concluded that quenching agent and electroless coating treatment explicitly affected the hardness of Al6061–Al2O3 composites.

Effect of Particle Size and Coating Parameters on the Uniformity of Ni-P Electroless Coating Applied on SiC Particles

Effect of Particle Size and Coating Parameters on the Uniformity of Ni-P Electroless Coating Applied on SiC Particles

Microwave-Mediated Electroless Coating of Copper on Hollow Fly Ash Microspheres

Hollow fly ash microspheres (FAMs) were successfully coated with copper (Cu) deposits via microwave (MW) irradiation. Ascorbic acid was used to reduce Cu2+ ions from copper sulphate pentahydrate solution. Subsequently, metallic Cu wasdeposited on FAMs within 2 to 6 min of MW irradiation. Microstructural examinations revealed that the sizes of the Cu coating on FAMs increased as MW time increased. The average approximate sizes increased from 1.56 μm to 4.04 μm as the MW processing time increased from 2 min to 6 min. Therefore, coating size could be controlled by adjusting MW irradiation time. Furthermore, EDX and XRD results confirmed the presence of Cu coating on FAMs, which agreed with the findings from the microstructural characterization. The results presented here showed that MW irradiation could be used to provide rapid and uniform heating of reactants to deposit Cu on FAMs within a short time. These Cu-coated FAMs have potential use as electrical conducting fillers in composite materials.

Comparing the Effect of Heat Treatment and Plasma-Nitriding on Corrosion Resistance of Ni-B-CNT Electroless Coating with Different CNT Concentration on AISI 4340 Steel

Comparing the Effect of Heat Treatment and Plasma-Nitriding on Corrosion Resistance of Ni-B-CNT Electroless Coating with Different CNT Concentration on AISI 4340 Steel

Corrosion and Wear Characteristics of Electroless Ni–P, Ni–P–W and Composite Ni–P–W/Al2O3 Coatings on AZ91 Sheet

Electroless Ni–P–W was coated on AZ91 sheets with various W contents and both the corrosion and wear resistance characteristics of these coatings were observed. The increase in W content resulted in a decrease in P content and an increase in the crystallinity of the electroless coatings. The corrosion resistance of the electroless coatings increased upon increase in W content of the electroless coatings up to approximately 5%. Above this content, however, the corrosion resistance tended to decrease due to the disturbed grain structure of the electroless coating. But both the surface hardness and wear resistance increased concurrently due to the positive contribution of W solid solution hardening. The applied heat treatment resulted in a decrease in the corrosion resistance due to the disappearance of the amorphous structure and increase in both the surface hardness and wear resistance due to the precipitation hardening. Al2O3 dispersion was better with the nonionic surfactant, as compared to the anionic and cationic surfactants. Composite coating reduced the corrosion resistance and increased the wear resistance of the electroless Ni–P–W coatings. The applied heat treatment was observed to have positive contribution to Ni–P–W coatings in getting the optimum corrosion and wear resistance combination.

Estimation of Zwitterionic Surfactant Response in Electroless Composite Coating and Properties of Ni–P–CuO (Nano)Coating

Electroless Ni–P and Ni–P–CuO coating on mild steel was developed successfully with the addition of Zwitterionic surfactant. The usage of nano-CuO in electroless coating was intermittent though the cost is low with high catalytic activity. Zwitterionic surfactant was introduced into the composite coating for the first time to increase the suspension of nanoparticles effectively during the coating process. Surfactant helps to reduce the intermolecular attraction between the solid and liquid interfaces and hence binding of nanoparticles with the hydrogen gas bubbles was eliminated. Also agglomeration of nanoparticles was controlled by stirring the electrolyte continuously using magnetic stirrer. The characterization and tribological properties were tested for the newly developed composites. Scanning electron microscope micrograph reveals the deposits are produced without any defects and the presence of CuO nanoparticles in the deposit. Energy-dispersive spectroscopy measurement shows the changes of weight percentage of elements available in the substrate. The surface roughness of the deposit was improved with the addition of CuO, it packs the gap between two grains and offers smooth finish and as the result the surface properties are modified. Microhardness of the substrate was improved for the substrate added with nano-CuO. The corrosion resistance of the substrate was improved when compared to the substrate produced using electroless Ni–P binary coating. Zwitterionic surfactant reduces the agglomeration of nanoparticles during chemical reaction and allows the particles to coat only on the target. Similarly, this technique can be implemented in the production of other composites in electroless coatings.

Duplex Ni-Zn-Cu-P/Ni-P electroless coating on magnesium alloy via maleic acid pretreatment

In this work, the duplex Ni-Zn-Cu-P/Ni-P electroless coating was applied on the AM60B magnesium alloy via new maleic acid pretreatment for potential applications in automobile industry. Also, the binary Ni-P coating was applied using the same pretreatment in order to compare the results. Scanning Electron Microscopy (SEM) images revealed that a cracked conversion film was created on the AM60B alloy after pretreatment in maleic acid solution. The binary Ni-P and duplex Ni-Zn-Cu-P/Ni-P electroless coatings with cauliflower-like micromorphology were successfully applied on the alloy surface after the maleic acid pretreatment. The duplex coating showed more regular and compact surface morphology as compared to the binary coating. The thickness of the electroless coatings were estimated by the cross-sectional SEM images which revealed that the inhibitory action of Zn2+ ions on the plating rate was fully compensated by the addition of Cu2+ ions. The microstructure and elemental composition of the electroless coatings were assessed by the X-ray Diffraction (XRD) and Energy Dispersive X-ray Spectroscopy (EDS), respectively. The binary coating demonstrated semi-amorphous microstructure while the duplex coating showed almost fully amorphous structure due to its high phosphorus (10.25wt%) and considerable zinc (7.55wt%) contents. Large ennoblement of the corrosion potential after application of the electroless coatings was revealed by Potentiodynamic Polarization (PDP) experiments in 3.5wt% NaCl solution. Also, the corrosion current density of the bare alloy was significantly diminished after the electroless plating. The duplex coating showed relatively better corrosion protection capacity than the binary coating. The results of the PDP tests were confirmed by Electrochemical Impedance Spectroscopy (EIS) experiments in the same corrosive media. The micro-hardness of the bare alloy was remarkably increased after application of both the binary and duplex electroless coatings. The duplex coating showed relatively higher micro-hardness as compared to the binary coating due to the gain refinement. The applied electroless coatings were adherent which was revealed by the thermal shock and pull-off tests.

Ultrasonic-Assisted Electroless Coating of Ni-B Alloy and Composites on Aluminum Alloy Substrates

Electroless nickel coating is one of the versatile methods to improve the physical properties of aluminium alloys. The increasing demand for high corrosion resistant surface with improved performance leads to the development of poly-alloy and composite coatings with the aid of ultrasonication. In the present study Ni-B alloy and Ni-B-CeO2 composite coatings were made on 356 aluminium alloy surfaces. The variation in structural and mechanical properties of coatings formed under both ultrasonication and magnetic stirring were investigated. Surface analysis by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) has shown the formation of more uniform coating under ultrasonication. The electrochemical polarization tests show enhanced corrosion resistance in ultrasonic assisted coatings.

Calculating of the Relative Preference of Criteria Affecting Electroless Coating of Alumina Nano Particles on Ni-B by Analytic Hierarchy Process (AHP) Method

In metallurgical engineering, there are different criteria affected on coating on surface of the material such as physical, chemical, mechanical, electrical and economical properties. In this study, using the Analytic Hierarchy Process (AHP) to calculation the performance of criteria for priority by addition of different concentration alumina (Al2O3)nanoparticles in Electrolyte and heat treatment on substrate nickel-borne electroless method has been calculated. The alumina particles with an average grain size of 50nm in different concentrations were added to a solution electroless Ni-B plating which were coated on conventional steel sample. The AHP determined that the most favorable concentration of alumina particles is 1gr/lit .

Effect of sodium sulfate on the characteristics and corrosion behavior of high phosphorus Ni-P electroless coatings

In this study, the effect of sodium sulfate on the microstructure and corrosion resistance of high phosphorus Ni–P electroless coatings has been investigated. Ni–P electroless coating was deposited on AISI 1045 steel substrate with using sodium sulfate as an additive in the plating bath (with concentration of 0–1.5 g/L). Electrochemical behavior and corrosion resistance of the coatings were investigated by evaluation of open circuit potential (OCP) and potentiodynamic polarization curves. The results showed that at an optimum concentration of sodium sulfate (∼1 g/L), deposition rate was maximum and the size and number of microporosities in the coating decreased to the minimum values. In addition, the best corrosion resistance and the most extensive passive region in potentiodynamic polarization curve was obtained at the optimum concentration of additive. Also its OCP was the same as pure nickel.