Concentrations Of SiC Nanoparticles Research Articles

Influence of SiC nanoparticle contents on microstructural evolution and mechanical behavior of AZ91D magnesium matrix composites synthesised through a combination of a master pellet feeding technique and stir casting assisted by ultrasonic vibration

In this current study, an integrated approach involving a master pellet feeding technique and stir casting assisted by ultrasonic treatment processing was employed to fabricate AZ91D magnesium matrix nanocomposites reinforced with various concentrations of SiC nanoparticles (1.0, 1.5, and 2.0 wt%). The influence of the nanoparticle feeding method and the weight fraction of reinforcement on the microstructure and mechanical properties of AZ91D/SiC composites was thoroughly examined. The microstructural analysis revealed that the implementation of a master pellet feeding approach resulted in a relatively uniform dispersion of SiC nanoparticles within the primary α–Mg phase, whereas the original nanoparticle feeding method led to noticeable particle agglomeration in the microstructure. Additionally, with an increasing weight fraction of SiC nanoparticles, the primary α-Mg grain became finer and the β-Mg17Al12 intermetallic phase turned smaller. The hardness and tensile properties of AZ91D/SiC composites were significantly enhanced with increasing SiC contents. The addition of 2.0 wt% SiC reinforcements to the AZ91D magnesium alloy resulted in a maximal hardness increase of 41 %. Nevertheless, the ultimate tensile strength (UTS) and elongation (%EL) decreased when the SiC content exceeded 2.0 wt% due to the presence of increased porosity content and particle clusters in the microstructure. Notably, the AZ91D/1.5 wt% SiC composite exhibited promising tensile properties, with yield strength (YS), ultimate tensile strength (UTS), and elongation (%EL) values of 151 MPa, 192 MPa, and 4.54 %, respectively.

A study on the microhardness and corrosion behavior of the ZnO and SiC reinforced multi layer electroless nickel coating

ABSTRACT An attempt has been made to fabricate electroless duplex (Ni-P-ZnO/Ni-P-SiC) coatings on the mild steel materials. Present investigation focused on ZnO and SiC nanoparticles concentration on the corrosion resistance and microhardness of duplex coating. Coated substrates are characterised by using the X-ray diffraction analyses to know the structure of deposit. Surface morphology and element composition was evaluated by means of scanning electron microscope (SEM) attached with the energy dispersive spectrometer (EDX). Coating was heat treated for 1 hour at 400°C temperature. Microhardness of the coatings was examined by using Vickers microhardness tester. Corrosion parameters of the duplex coating were evaluated by performing the potentiodynamic polarisation studies in 3.5% NaCl solution. Experimental observations confirm that Ni-P-SiC outer layered coating offers maximum microhardness and duplex coating with Ni-P-ZnO as external layer provides maximum corrosion protection. Maximum load bearing ability of SiC nanoparticles offers superior microhardness to the Ni-P-SiC external layer coatings. Higher electrochemical resistive ZnO nanoparticles provide good corrosion protection to the Ni-P-ZnO external layer coatings. Formation of intermetallic compounds after heat treatment process enhances the both the coatings microhardness and resistance to corrosion.

Influence of Particle Concentration on the Elemental Penetration Region and Properties of Ni-P-SiC Composite Coatings Prepared through Sandblasting and Scanning Electrodeposition on 45 Steel Surfaces

Ni-P-SiC composite coating was prepared on 45 steel surfaces through sandblasting and scanning electrodeposition to explore the relationship between element penetration region and composite coating properties. The single-factor control variable method with particle concentration as the research variable was used. Results showed that with the gradually increasing concentration of SiC nanoparticles, a trend of first increasing and then gradually decreasing was observed for the surface and cross-sectional microstructure of the coating, interpenetration ability of the elements, adhesion performance, and corrosion resistance. The best deposition quality of the coating was obtained when the concentration of SiC nanoparticles was 3 g·L−1. For cross-sectional microstructure, the scratch test revealed that the maximum coating thickness was 17.3 μm, the maximum range of elemental penetration region was 28.39 μm, and the maximum adhesion of the composite coating was 36.5 N. The electrochemical test showed that the composite coating had a −0.30 V self-corrosion potential and 8.45 × 10−7 A·cm−2 self-corrosion current density, the slowest corrosion rate. In addition, the composite coating had the best corrosion resistance and the largest impedance arc radius corresponding to an equivalent impedance value R2 of 3108 Ω.

Effect of SiC addition in electrolyte on the microstructure and tribological properties of micro-arc oxidation coatings on Al-Mg-Sc alloy

sHard and wear-resistant ceramic coatings with SiC nanoparticles were in situ fabricated on Al-Mg-Sc alloy using micro-arc oxidation (MAO) method in alkaline silicate electrolyte. The microstructure, roughness, and composition of the MAO coatings were characterized by scanning electron microscopy (SEM), x-ray diffraction (XRD) and laser scanning confocal microscopy (LSCM), respectively. The microhardness of the MAO coatings was obtained microhardness tester. The wear resistance of the MAO coatings was evaluated by ball-on-disc reciprocating tribo-tester. The results showed that the phase composition of the obtained coatings with the typical pancake-like stacking structures was mainly composed of α-Al2O3 and γ-Al2O3. the porosity and roughness gradually decreased with the increment of SiC nanoparticles concentration. Al content gradually decreased from the matrix to the outside, while the Si content gradually increased. The incorporation of SiC nanoparticles further increased the microhardness of the MAO coating. Especially in alkaline silicate electrolyte with 1.5g l−1 SiC nanoparticles, the microhardness could reach 1270 HV0.5. The friction coefficient of the MAO coatings prepared in electrolyte solution with SiC addition varied from 0.4 to 0.55, and the ceramic coating with 1.5g l−1 SiC nanoparticles exhibited the best wear resistance. The wear mechanism was attributed to be the combination of abrasive wear, adhesive wear and oxidation wear.

Surfactant-free commercial electroless bath with low concentration of SiC nanoparticles to prepare the NiP-SiC nanocomposite coatings

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 test. By co-deposition of SiC nanoparticles, the hardness of heat-treated NiP is significantly increased (near 25%) and the wear loss is reduced (near 48%), especially at high sliding distance during wear test. The sample prepared through the surfactant-free electroless bath containing the 1 g l−1 SiC nanoparticle showed the best corrosion as well as wear resistance.

Effect of SiC nanoparticles concentration on novel feedstock Moringa Oleifera chemically treated with neopentylglycol and their trobological behavior

The increase in energy demand and deterioration of the petroleum products encouraged industrialists to search for environmentally friendly products. In this study, an attempt has been made to explore the potential of Moringa Oleifera oil for bio-based lubricant application. The Moringa Oleifera oil was modified through the chemical process with Neopentylglycol treatment. After chemical modification, the nanoparticles were added to the oil in different proportions. The physicochemical properties of the lubricants were tested according to the ASTM standards. The tribological application was examined using a pin on disc tribometer. For the examination of the worn surfaces, a scanning electron microscope was used. An improvement in the physicochemical properties of the lubricant was observed at 0.5% concentration. Increment in viscosity increment, relative viscosity becomes more at 1.0% nanoparticles concentration and 100 °C temperature. The proper dispersion at 0.5% nanoparticles addition was obtained and confirmed through the test. The reduction in the friction coefficient and wear of the parts was observed with chemically modified oil and optimum concentration of the 0.5% nanoparticles was found. The 1.0% concentration of nanoparticles showed higher wear of the parts due to their agglomeration on the surface. The worn surfaces during 0.5% nanoparticles addition to the lubricant also display minimum wear.

Fabrication of the Ni-W-SiC thin film by pulse electrodeposition

The present work reports the preparation of Ni-W-SiC thin films obtained by pulse current (PC) electrodeposition using a watt-type nickel plating solution, which contains SiC nanoparticles (NPs). Effects of the initial SiC NP concentration on the morphology, structure, crystal size, microhardness, and corrosion resistance of the resulting Ni-W-SiC thin films were investigated using by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), atomic force microscopy (AFM), microhardness tests, and electrochemical workstation. The results indicated that the surface of Ni-W-SiC films that were treated using 9 g/L SiC NPs had a fine-grained, smooth, and very uniform surface. Incorporating SiC NPs into the Ni-W-SiC thin-film influenced the metal grain sizes and microhardness of the layers. When the concentration of SiC NPs was 9 g/L, the average crystal size was 67 nm, and the microhardness was 881.7 HV. Moreover, the as-obtained film produced with a concentration of 9 g/L SiC had the minimum corrosion current value of 1.5 × 10−3 mA/cm2, which demonstrates its excellent corrosion resistance.

STUDY ON MICROSTRUCTURE AND WEAR PROPERTIES OF GRAPHENE AND SICP HYBRID REINFORCED ALUMINUM MATRIX COMPOSITES

Graphene and SiC nanoparticles hybrid reinforced aluminum matrix composites were prepared by ball milling and hot press sintering. The effect of graphene content on microstructure and wear properties of composites was investigated. The results show that increasing the graphene content is beneficial to maintain the structural integrity of graphene during ball milling and hot pressing sintering, and to reduce the stress concentration of SiC nanoparticles on the matrix. The wear resistance of the composite is improved with the increase of graphene content. As the graphene content increases, the wear mechanism changes from abrasive wear to delamination wear. Through the analysis of the cross-sectional morphology of the wear marks, it is found that the improvement of the wear resistance is based on the formation of a graphene-rich dry lubricating layer on the worn surface, which explains the formation mechanism of the graphene dry lubricating layer in the composite.

Nano SiC Reinforced Copper Nanocomposite by a Simple Electrodeposition Method

The Cu and Cu-SiCnanocomposite coatings were prepared by a simple electrodeposition technique from acidic copper sulphate electrolyte using SiC nanoparticles with an average particles size of 50 nm under optimized bath composition and preparation conditions for possible electrical contact material applications such as electrical switch and wiring boards where higher electrical conductivity and thermal conductivity is required. The scope of the present study is to enhance the strength, mechanical, corrosion and wear resistance properties of Cu-SiCnanocomposite compared to pure Cu coatings. The as prepared Cu and Cu-SiCnanocomposites were characterized for structural, mechanical and corrosion resistance properties by EDX, XRD, FESEM, Vickers microhardness tester and AC-impedance and Tafel polarization techniques. The elemental composition (wt% of Cu and SiC nanoparticles) of Cu-SiCnanocomposites was analyzed by EDX coupled with FESEM analysis confirms the presence of nanoSiC in the copper matrix and they were 89wt% of Cu and 11 wt% of SiC nanoparticles respectively. The surface morphology of Cu and Cu-SiCnanocomposites was studied by FESEM analysis shows that SiC nanoparticles were uniformly dispersed in the surface of the copper matrix compared to pure copper. The crystallite structure and grain size of the Cu and Cu-SiCnanocomposite electrodeposits was measured by XRD analysis. From the XRD results, the grain size calculated using Debye-Scherrer’s formula was ~35 nm for pure Cu and ~33 nm Cu-SiCnanocomposite. The crystallite structure of Cu and Cu-SiCnanocomposites was fcc (face centered cubic) and the preferred orientation of the plane was (220). The microhardness of Cu-SiCnanocomposite coating increased with increasing SiC nanoparticles concentration in the bath compared to pure Cu coating. The corrosion resistance measurements were performed for the pure Cu and Cu-SiCnanocomposite coatings by electrochemical impedance spectroscopy (EIS) and Tafel polarization techniques. It shows that, Cu-SiCnanocomposites has high corrosion resistance than pure Cu in 3.5wt% NaCl solution.

Enhanced microalgal growth and lipid accumulation by addition of different nanoparticles under xenon lamp illumination.

In this study, the growth and lipid accumulation of Scenedesmus sp. using different nanoparticles and light sources were investigated. Xenon lamp can produce a broad illumination spectrum, and exhibited better performance than light-emitting diode. SiC and g-C3N4 nanoparticles improved the biomass and lipid accumulation, whereas TiO2 and TiC nanoparticles had inhibitory influence on microalgae. Lipid production can be improved by oxidative stress produced by combination of nanoparticles and xenon lamp irradiation. At the optimal SiC nanoparticles concentration of 150 mg L-1 and photoperiod of 6:18 h, the maximum biomass concentration and total lipid content reached 3.18 g L-1 and 40.26%, respectively. The addition of SiC nanoparticles could promote the substrate utilization rate and induce stress condition, thereby enhancing the activity of acetyl-CoA carboxylase and lipid biosynthesis. This research shows that SiC nanoparticles addition combined with xenon lamp illumination is a promising strategy to promote microalgal growth and lipid accumulation.

Fabrication of PVA/NiO/SiC Nanocomposites and Studying their Dielectric Properties For Antibacterial Applications

PREPARATION of PVA/NiO/SiC nanocomposites and studying their dielectric properties for antibacterial applications have been investigated. The A.C electrical properties of nanocomposites were studied in frequency ranging (100-5×106) Hz at room temperature. The experimental results showed that the dielectric constant and dielectric loss of (PVA-NiO-SiC) nanocomposites were decreased with an increasing the frequency of applied electric field. The A.C electrical conductivity increases with increasing of frequency. The dielectric constant, dielectric loss and A.C electrical conductivity of (PVA-NiO) nanocomposites were increased with increasing of SiC nanoparticles concentrations. The antibacterial applications for (PVA-NiO-SiC) nanocomposites tested against gram-positive (S. aureus) and gram-negative (E. coli). The results showed that the inhibition zone was increased with increase the concentrations of SiC nanoparticles.

Cathode plasma electrolytic deposition of Al2O3 coatings doped with SiC particles

Semiconductor particles doped Al2O3 coatings were prepared by cathode plasma electrolytic deposition in Al(NO3)3 electrolyte dispersed with SiC micro- and nano-particles (average particle sizes of 0.5–1.7 µm and 40 nm respectively). The effects of the concentrations and particle sizes of the SiC on the microstructures and tribological performances of the composite coatings were studied. In comparison with the case of dispersing with SiC microparticles, the dispersion of SiC nanoparticles in the coatings was more uniform. When the concentration of SiC nanoparticles was 5 g/L, the surface roughness of the composite coating was reduced by 63%, compared with that of the unmodified coating. Friction results demonstrated that the addition of 5 g/L SiC nanoparticles reduced the friction coefficient from 0.60 to 0.38 and decreased the wear volume under dry friction. The current density and bath voltage were measured to analyze the effects of SiC particles on the deposition process. The results showed that the SiC particles could alter the electrical behavior of the coatings during the deposition process, weaken the bombardment of the plasma, and improve the structures of the coatings.

Influence of SiC Nano Particles on Microhardness and Corrosion Resistance of Electroless Ni–P Coatings

Silicon carbide nanoparticles were co-deposited in Ni–P matrix to form Ni–P–SiC composite coating on the mild steel substrate by using electroless coating technique. In the present study, the effect of SiC nanoparticles concentration and heat treatment temperature on microhardness and corrosion resistance of the Ni–P–SiC coating was investigated. The microhardness and corrosion resistance of the coating was further analyzed through the experiments. X-ray diffraction and scanning electron microscope attached with energy dispersive spectroscopy were used to analyze phase structure, morphology, and elemental composition of the coating. Results confirm that incorporation of SiC nanoparticles into the coating greatly influences the microhardness and corrosion resistance of the coating. The phase change from amorphous Ni to crystalline nickel and nickel phosphide at 400 °C further improves the microhardness and corrosion resistance of the composite coating.

Preparation of Ni-W/SiC nanocomposite coatings by electrochemical deposition

Ni-W/SiC nanocomposite coatings were electrodeposited in modified Ni-W electrolytes containing suspended SiC nanoparticles. Deposition parameters including SiC nanoparticles concentration in the electrolyte, current density and deposition time were optimized for the highest corrosion and wear resistance of the composite coatings: the current density 1–2 A dm−2, SiC concentration 6 g L−1 and deposition time 10–30 min. The influence of electrodeposition parameters on the morphologies, corrosion behavior, microhardness and wear resistance of the nanocomposite coatings were investigated. The nanocomposite coatings were characterized by scanning electron microscopy, energy dispersive X-ray analysis (EDX), X ray diffraction (XRD) and electrochemical technique. The results indicated that SiC content in the composite coatings increases with the increase of SiC concentration in the baths and more SiC nanoparticles will incorporated in the coatings at 2 A dm−2. SiC and W content in the deposits varied with the change of the current density, deposition time and SiC concentration in the bath. The incorporation of SiC nanoparticles alters the chemical composition of Ni-W, enhances the microhardness of the composite coatings and significantly strengthens the anti-corrosion behavior and wear resistance of the coatings. The composite coatings have a good application prospect for metal protection in harsh corrosion environment.

Thermal degradation and optical properties of SiC-infused polystyrene nanocomposites

The thermal degradation kinetics of polystyrene (PS) and various polystyrene–silicon carbide (PS/SiC) nanocomposite has been examined in detail and studied the reaction kinetics using non-isothermal thermogravimetry in nitrogen atmosphere at different heating rates. The activation energy of the thermal degradation was calculated using model-free methods of Kissinger–Akahira–Sunose and Tang, and the values are found to be compatible with each other. The kinetic analysis of the series of the prepared composites shows an increase in the average activation energy values with increase in the concentration of SiC nanoparticles, and the power law is found to be the best to describe the reaction model. The effect of various concentrations of SiC nanoparticles on the optical properties of the composites has been studied. The band gap energy of the nanocomposites decreases with SiC content. The SiC nanoparticles enhance the UV absorption of the composite film and modify overall optical behavior of the composite films. Further, the electronic structure and bonding properties of SiC-infused polystyrene molecule have been studied based on the DFT method by using the Gaussian09W simulation package to predict the stability and reactivity. The geometries have been analyzed using B3LYP/6-31G basis set .

The Correlation Among Deposition Parameters, Structure and Corrosion Behavior in ZnNi/Nano-SiC Coating

The present work explores how deposition parameters affect structural and morphological characteristics of ZnNi/nano-SiC composites in order to engineer an environmentally benign corrosion-resistant coating. In this regard, ZnNi and ZnNi coatings containing SiC nanoparticles were electrodeposited from chloride bath by direct current method, and the effects of SiC concentration, deposition current density and two types of surfactant (sodium dodecyl sulfate, SDS, and hexadecyltrimethyl ammonium bromide, HTAB) were investigated. Increasing SiC nanoparticles concentration in the electrolyte enhances the SiC content of the coating and can affect the coating composition, structure and morphology. Elevation of deposition current density may reduce SiC content of the coating, yet this decline can be compensated by the addition of HTAB. Application of 11 g/L SiC nanoparticles produced a coating with a more even surface and less porosity that had the highest corrosion resistance. The presence of nanoparticles seemingly reduces the available surface for electrochemical reactions and decelerates corrosion.

Wear and corrosion resistance and electroplating characteristics of electrodeposited Cr–SiC nano-composite coatings

Cr–SiC nanocomposite coatings with various contents of SiC nanoparticles were prepared by electrodeposition in optimized Cr plating bath containing different concentrations of SiC nanoparticles. Direct current electrocodeposition technique was used to deposit chromium layers with and without SiC nanoparticles on mild carbon steel. The effects of current density, stirring rate and concentration of nanoparticles in the plating bath were investigated. Scanning electron microscopy was used to study surface morphology. Energy dispersive analysis technique was used to verify the presence of SiC nanoparticles in the coated layers. The corrosion behaviors of coatings were investigated by potentiodynamic polarization and electrochemical impedance spectroscopy methods in 0.05 mol/L HCl, 1 mol/L NaOH and 3.5% NaCl (mass fraction), respectively. Microhardness measurements and pin-on-disc tribometer technique were used to investigate the wear behavior of the coatings.

Microhardness of Electroless Composite Coating of Ni-P with SiC Nano-Particles

A central composite rotatable orthogonal experimental design of response surface methodology (RSM) was employed to find the optimum parameters combination of microhardness of electroless composite coating of Ni-P with SiC nano-particles. Microhardness of electroless composite coating was used as response function, and three parameters, namely, coating liquid temperature, PH, the concentration of SiC nano-particles were selected as influence factors. Nano-particles were dispersed using ultrasonic. The effects of every factor on response function were analyzed, and the optimum combination for three parameters were obtained, which one was 84~86°C of coating liquid temperature, 5.3~5.7 of PH and 4.5 g/L of concentration of SiC nano-particles. The optimum result was microhardness of electroless composite coating more than 1000 HV after heat treatment.

Evaluation of Corrosion Properties of Electroless NiP/Nano-SiC Composite Coatings

Ni-P/nano- SiC composite coatings were deposited in different concentrations of SiC nano-particles in the bath. The hardness and corrosion resistance of the composite coatings with different content of SiC nano-particles were measured. Moreover, the structure of the composite coatings was investigated by means of X-ray diffraction (XRD), while their morphologies and elemental composition were analyzed using scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS). Results showed that co-deposited SiC nano-particles contributed to increase the hardness but corrosion resistance of electroless Ni-P coatings decreased due to agglomeration of nano-particles and increasing porosity of coatings.

Corrosion assessment of electroless nickel–phosphorous/nanosilicon carbide composite coatings

Electroless nickel–phosphorous (Ni–P)/nano-SiC (silicon carbide) composite coatings were deposited onto API-5L-X65 steel substrates in the absence of any surfactants at different concentrations of SiC nanoparticles in the plating bath. The hardness and corrosion resistance of the composite coatings with different content of SiC nanoparticles were measured. Moreover, the structure of the composite coatings were investigated by means of X-ray diffraction, whereas their morphologies and elemental composition were analysed using scanning electron microscope equipt with energy dispersive spectrometer. Results showed that co-deposited SiC nanoparticles contributed to increase the hardness, but the corrosion resistance of the composite coatings depends on dispersion of nanoparticles throughout the coatings and decreases because of agglomeration of nanoparticles and porosity of the coatings.