Effect Of SiC Nanoparticles Research Articles

Correction: Effect of SiC nanoparticles on properties of laser cladding IN718 coating

Correction: Effect of SiC nanoparticles on properties of laser cladding IN718 coating

Effect of SiC Nanoparticles on the Structure and Properties of Ni+W-SiC Nanocoatings

Effect of SiC Nanoparticles on the Structure and Properties of Ni+W-SiC Nanocoatings

The Effect of SiC Nanoparticles’ content on Mechanical Properties and Wear Behavior of A380 Aluminum Alloy Nanocomposite Produced by Powder Metallurgy Method

The Effect of SiC Nanoparticles’ content on Mechanical Properties and Wear Behavior of A380 Aluminum Alloy Nanocomposite Produced by Powder Metallurgy Method

Effects of SiC nanoparticles on space charge behaviors of LSR/nano-SiO2/nano-SiC composites for insulating material of HVDC cable joints

In order to develop insulating materials for high-voltage direct current (HVDC) cable joints, silicone nanocomposites are prepared by mixing liquid silicone resin (LSR) with the surface-modified nano-SiO2 and the surface-modified SiC nanoparticles, and the effects of SiC nanoparticles on space charge behaviors of the silicone nanocomposites are studied. The hydrophilic surface of the fumed nano-SiO2 is modified into a hydrophobic surface by treating with an alkyl silane coupling agent in order to be uniformly dispersed in LSR, and the surface of the SiC nanoparticles is modified with a vinyl silane coupling agent in order to improve the interfacial characteristics through covalent bonds between SiC nanoparticles and LSR. LSR is mixed with the modified nano-SiO2 (20 wt%) and the modified SiC nanoparticle (0 wt%-9 wt%). To observe the even dispersion of the modified nano-particles in LSR matrixes, a transmission electron microscope is employed and it is found that nano-SiO2 and nano-SiC particles are somewhat uniformly dispersed regardless of their content. When an appropriate amount of semiconductive nano-SiC particles is uniformly dispersed in the LSR/SiO2 nanocomposite, space charges are evenly dispersed. Therefore, the HVDC breakdown strength of the LSR nanocomposite would increase. However, if nano-SiC is mixed in excess, the conduction paths are formed, therefore the HVDC breakdown strength would decrease. HVDC breakdown strength under positive polarity condition shows the maximum value, 99.8 kV/2 mm in the nanocomposite with 3 wt% nano-SiC, which means that the space charge distribution is optimal in the 3 wt% nano-SiC system. However, excessive nano-SiC adversely affects the HVDC breakdown strength.

Effects of SiC nanoparticles on the dissimilar friction stir weldability of low-density polyethylene (LDPE) and AA7075 aluminum alloy

Abstract Linear dissimilar friction stir welding (FSW) of metals and polymers displayed some attractive applications for crucial lightweight industries such as automotive. The substantial dissimilarity between these, unlike materials in terms of physical and mechanical properties, can affect the feasibility of this solid-state joining in an exceptionally challenging manner. In this article, an interesting approach is proposed to reduce such a tricky significant difference by strengthening the polymer during FSW treatment as the dissimilar weldment's weakest counterpart. A very soft polymer as low-density polyethylene (LDPE) and a relatively hard aluminum alloy as AA7075 were assessed under investigation for shifting the situation in terms of complexity toward the most critical state. Then, by pre-placing SiC nanoparticles inside the polymer side and afterward, they were introduced into the weld nugget during dissimilar materials mixing. The FSW processing parameters were optimized to reach a sound state of nanocomposite weld formation with superior mechanical performance. The cross-sectional investigation results announced the impact of SiC nanoparticles dispersion through the polymer matrix on dissimilar weldments' subsequent mechanical performance. The distribution of these reinforcing agents and their influence were considerably varied depending on the FSW processing parameters.

The effect of SiC nanoparticles and sintering temperature on the structural and wear properties of Cu–MWCNTs–SiC hybrid nanocomposites

Abstract SiC nanoparticles play an important role in Cu–MWCNTs nanocomposites. So far, the effect of SiC volume fraction has not been considered on the properties of Cu–MWCNTs–SiC hybrid nanocomposites. Copper-based hybrid nanocomposites with 2 vol.% carbon nanotubes and 1–3 vol.% SiC nanoparticles were prepared via powder metallurgy. The composite powders were compacted and then sintered at 850, 900 and 950 °C for 1 h. Increasing the volume fraction of SiC nanoparticles restricts the grain growth, decreases the friction coefficient, and increases the hardness and wear resistance of prepared nanocomposites. The coefficient of friction and wear rate of Cu–MWCNTs–SiC hybrid nanocomposites decreased with increasing SiC content. Nanocomposites sintered at 900 °C exhibited higher hardness and wear resistance compared to other samples. The highest hardness and wear resistance were related to the Cu-2 vol.% MWCNTs-3 vol.%SiC hybrid nanocomposite sintered at 900 °C, which shows approximately 24 and 78% improvement over the pure copper specimen, respectively. Wear resistance and hardness were reduced for samples sintered at 950 °C.

Effect of SiC nanoparticles on the precipitation behavior and mechanical properties of 7075Al alloy

In terms of aluminum alloy matrix composites, the effect of reinforcement on precipitation is worth investigating. In this work, the silicon carbide nanoparticles-reinforced 7075Al (SiCnp/7075Al) composite was fabricated through a series of powder metallurgy procedures, shift-speed ball milling, hot pressing, and hot extrusion, and the precipitation behavior of SiCnp/7075Al composite was compared with that of 7075Al alloy after T6 treatment. The results show that only a small addition (1 vol%) of SiCnp modifies the morphology and dispersion of precipitates. The uniformly dispersed small precipitates (η′ phase) and increased dislocation density have a positive influence on the mechanical properties of composites. Based on the fracture surface and element composition, a fracture mode dominated by precipitated phase-induced crack initiation was proposed. This study suggests a promising approach to design the alloy matrix composites through controlling the behavior of precipitated phases with nano-reinforcement.

Effect of SiC Nanoparticles on the Dispersion of Multiwalled Carbon Nano Tubes in AA 5083 by Stir Casting Technique

Abstract Multi Walled Carbon Nanotubes (MWCNT) exhibit outstanding thermal, electrical and mechanical properties. These properties of MWCNTs motivate in the fabrication of advanced nanocomposites for a significant increase in one of these properties. In this study, Aluminum Alloy 5083 was reinforced with 5% percentage of SiC and 0, 1.66, 3.33 % of Multi-walled Carbon Nanotubes (MWCNTs). The reinforcement was done by stir casting route. The cast thus produced were tested for their tensile strength. The tensile strength increased by 18%. The distribution of the two reinforcements was analyzed by obtaining SEM micrographs of the various casts. XRD was done to obtain the various elemental compositions. There were no intermetallic compounds formed. The interactions between SiC and MWCNT was studied.

Effect of SiC nanoparticles on in-situ synthesis of SiC whiskers in corundum–mullite–SiC composites obtained by carbothermal reduction

Corundum–mullite–SiC composites were synthesised using a carbothermal reduction method. The effects of SiC nanoparticles and sintering temperatures on the phase transformation of the composites and the synthesis of SiC whiskers were studied by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Results indicated that corundum, mullite, and SiC whiskers were produced as final products at 1600–1650 °C. SiC whiskers were formed through the vapor–solid mechanism. The added SiC nanoparticles worked as nucleating agents to facilitate the carbothermal reduction of aluminosilicates and formation of SiC whiskers. The sample with the added SiC nanoparticles exhibited a high yield of β-SiC of 17.1%. Furthermore, the SiC nanoparticles decreased the formation temperature of SiC whiskers from the original 1600 °C to 1500 °C, and the porosity of the composites was increased from 56.7% to 64.7% by increasing the partial pressure of SiO gas. This study provides an insight into the more efficient synthesis of composites with SiC whiskers through the carbothermal reduction of aluminosilicates.

Effect of SiC nano particles on grain stability of friction stir processed AA7075

Friction stir processing (FSP) is a new technique to produce fine-grained microstructure with enhanced microstructure characteristics and mechanical properties compared to the base metal (BM). However, microstructures are not stable under elevated temperature. The microstructure of the friction stir processed (FSPed) metallic substrate can be improved by reinforcing the matrix with secondary phase particles. With this motivation, aluminium alloy plate of typically AA7075-T651 is reinforced with nano-particles of silicon carbide (SiCNP) and the composites were processed by FSP at the tool-rotation speed (TRS) of 1000 rpm and the tool-traverse speed (TTS) of 25 mm/min with six passes. The grain stability of the composite was studied by heat-treating to temperatures range 450 °C–500 °C for various durations range 1 h 30 min to 4 h 30 min. Micro and macrostructure of heat-treated samples are characterized using an scanning electron microscopy (SEM) and optical microscope (OM). Results showed that even after 4 h 30 min of samples subjected to heat treatment, the grains structures of the FSPed composites were stable at 450 °C. Further, for higher temperatures, i.e. 475 °C and 500 °C, composite grain structures at the stir zone (SZ) were stable up to 3 h. In comparison, abnormal grain growth (AGG) was observed in the six-pass FSPed aluminium alloy plate of AA7075-T651 without addition of SiCNP and heat-treated for 450 °C for 1 h 30 min. Thus, these experimental investigations indicate that grain boundary pinning by SiCNP has significantly increased the stability of the grains under elevated temperature and results in grain refinement with average grain size range 1.5–2 µm at the SZ of the FSPed composites.

Effect of SiC nanoparticles on the wear behaviour of squeeze-cast AZ91–2.0Ca–0.3Sb alloy

ABSTRACTThe dry sliding wear behaviour of the AZ91–2.0Ca–0.3Sb alloy and the AZ91–2.0Ca–0.3Sb–xSiCnp nanocomposites have been investigated. The wear rate is lower for all the nanocomposites compared to the alloy. All the nanocomposites demonstrate the lower specific wear rates than the alloy. Among the nanocomposites, the one containing 2.0SiCnp exhibits the best tribological performance. The values of the coefficient of friction are lower for the nanocomposites than the alloy. The abrasion, adhesion, oxidation, and delamination are the dominant wear mechanisms. The 3D topography depicts that the addition of SiCnp to the AZ91–2Ca–0.3Sb alloy results in the reduced surface roughness during the wear tests, confirming the superior wear behaviour of the nanocomposites compared to the alloy.

Effect of SiC nanoparticles on the microstructure and texture of friction stir welded AA2024/AA6061

In the present study, the effect of SiC nanoparticles on the microstructure and texture evolution of friction stir welded AA2024/AA6061 dissimilar joint investigated. The results showed that the SiC nanoparticles homogeneously dispersed in the aluminum matrix. The Al/SiC interfaces had a good quality of bonding between particles and matrix. It was found that the new recrystallized aluminum grains tend to nucleate and grow on the 11¯1 crystal plane of SiC nanoparticle (1¯1¯1Al facet on 11¯1SiC surface). The average grain size in the stirred zone (SZ) decreased to 7.4 μm owing to the grain refinement through the occurrence of both dynamic and static recrystallization. Most grains in the center of the stirred zone grown due to the occurrence of continuous grain growth (CGG) mechanism after the stirring. Moreover, the incorporation of SiC nanoparticles led to a reduction of 26% in the mean grain size of the SZ. The average size of the precipitate particles in the stirred zone was much smaller than the thermo-mechanically affected zone (TMAZ) owing to the dissolution of precipitates during stirring and reprecipitation during cooling. In addition, the grain size of the stirred zone on the advancing side was lower than the retreating side (2.6 μm vs. 9.7 μm). The results revealed a weaker texture after FSW compared to the initial samples. The SiC nanoparticles largely suppressed the rotation of the {001}〈100〉 oriented new grains through particle pinning effect. Unlike the advancing side, there was no recrystallization texture component on the retreating side.

Enhanced thermoelectric performance of BiSbTe alloy: Energy filtering effect of nanoprecipitates and the effect of SiC nanoparticles

p-type Bi0.46Sb1.54Te3 samples containing nanoprecipitates are prepared by mechanical alloying (MA) and spark plasma sintering (SPS) technique. The thermoelectric performance of Bi0.46Sb1.54Te3 is improved by the energy filtering effect induced by nanoprecipitates, leading to a high ZT value of 1.18 at 325 K. To further improve the thermoelectric performance of Bi0.46Sb1.54Te3, SiC nanoparticles are dispersed into Bi0.46Sb1.54Te3 matrix. The addition of SiC simultaneously increases the electrical conductivity and the Seebeck coefficient. Meanwhile, it also decreases the lattice thermal conductivity from 0.38 to 0.33 Wm−1K−1 for the 0.2 wt% SiC sample. Consequently, a maximum ZT value of 1.45 at 325 K is obtained for Bi0.46Sb1.54Te3 with the addition of 0.2 wt% SiC composites, which increases about 23% than the pristine sample.

Influence of SiC nanoparticles addition on the microstructure, thermal and tensile properties of Sn–Zn–Ag solder alloy

The effect of SiC nanoparticles (NPs) addition on the microstructure, thermal and tensile properties of Sn–Zn–Ag solder alloy (SZA822) was studied. Mechanical mixing technique has been utilized to disperse SiC in SZA822 at 673 K for 3 h. Microstructure analysis revealed the plain SZA822 and SZA822–0.5 SiC composite solders are mainly composed of Sn, IMCs of Ag3Sn & AgZn and Zn. But, after SiC addition, Ag3Sn particles were refined while AgZn partially dissolves in the Sn-matrix. One endothermic peak appeared in each solder alloy which confirms one-step melting. The melting temperature is maintained at the SZA822 level. Tensile results showed that the levels of the stress-strain curves were sensitive to the values of deformation temperature Td, strain rate and SiC loading. The ultimate tensile strength () increases while total strain (εT) decreases with SiC loading. So, SiC NPs act as a reinforcing agent. The strain rate sensitivity index (m) of composite solder was 0.09 and for SZA822 it was 0.11. Finally, the value of the activation energy Q of composite solder was 73.7 KJ/mole which is higher than that of SZA822 (61.7 KJ/mole). The Q values suggest that the dislocation motion mechanism is applicable in this work.

The influence of nanoparticles on dendritic grain growth in Mg alloys

Melt processing offers a cost effective method for producing metal matrix nanocomposite (MMNC) components; however, the influence of nanoparticles on the evolving microstructure during solidification is still not well understood. In this study, the effect of SiC nanoparticles on α-Mg dendrite evolution in a Mg-25Zn-7Al (wt.%) alloy was investigated through 4D (three dimensions plus time) synchrotron tomographic quantification of solidification experiments conducted at different cooling rates with and without nanoparticles. Key features of the solidifying primary α-Mg dendritic grains were quantified, including grain morphology, size distribution, and dendrite tip velocity. To obtain the high-contrast tomography dataset necessary for structure quantification, a new image reconstruction and processing methodology was implemented. The results reveal that the addition of nanoparticles increases grain nucleation whilst restricting dendritic growth and altering the dendritic grain growth morphology. Using LGK model calculations, it is shown that these changes in solidification microstructure occur as a result of nanoparticle-induced restriction in Zn's effective diffusivity ahead of the dendrite tips, reducing tip velocity. The results both suggest the key phenomena required to be simulated when numerically modelling solidifying Mg-based MMNC and provide the data required to validate those models.

Microstructural modification and strength enhancement by SiC nanoparticles in AZ31 magnesium alloy during hot rolling

Effects of SiC nanoparticles on the microstructural and textural evolutions of AZ31 matrix alloy during hot rolling were investigated. The addition of SiC nanoparticles can strongly inhibit the formation of shear bands, which are much more prevalent in matrix alloy sheets. Compared with pristine AZ31 alloy, the nanocomposite is characterized by a lamellar structure which is composed by the alternative a fine grain layer and a coarse grain layer. The lamellar structure was caused by the nanoparticle bands in as-rolled sheet. The fine grain layer was caused by the pinning effects of nanoparticles on recrystallized grain growth. Moreover, nanoparticles complicatedly altered the basal texture intensities of the matrix in the nanocomposite, instead of the reported simply weakening effect. For the mechanical strengths, the hot rolling leads to remarkable enhancement for both of nanocomposite and alloy sheets. However, the former ones always show superior value than the latter ones. Inhibited shear bands, nanoparticles bands and the associated lamellar structure do benefit the stronger mechanical properties in the nanocomposite sheets.

Effects of SiC Nanoparticles on the Properties of Titanium-Matrix Foams Processed by Powder Metallurgy

Metal-matrix foams are used widely for structural applications such as impact energy absorption, vibration resistance and weight reduction. In this study titanium nanocomposite foams with different porosity percentages were produced using TiH2, as foaming agent, by powder metallurgy technique. At first, raw materials including titanium powder and different weight percentages of SiC nanoparticles were mixed and then different amounts of TiH2 were added to the mixture. The mixture was compacted at 200 MPa. The samples were heat treated in two stages, first at 400 °C for 1 h, as a partial sintering, and then at 1050 °C for 2 h, as foaming treatment. Mechanical and structural properties such as compressive strength, energy absorption, porosity percentage and relative density of samples were measured and compared together. Thermo gravimetric analysis (TGA), differential thermal analysis (DTA), scanning electron microscopy (SEM) and X-ray diffraction (XRD) were performed on foaming agent and samples. The results showed uniform distribution of SiC nanoparticles in titanium matrix and also homogenous pore structure. It was concluded that with increasing SiC weight percent, relative density is increased to 0.43 in the sample with 1.5 wt % SiC. Besides, the measured compressive strength of samples was in the range of 14.4–32.3 MPa. Moreover, it was concluded that the energy absorption of samples increases with increasing SiC nano particles up to 33.09 MJ/m3.

Mechanical properties and morphology of aluminium metal matrix nanocomposites-stir cast products

In the present work, A356/SiC nanocomposites have been fabricated through stir casting process. Mechanical properties, morphology and effect of SiC nanoparticles on A356/SiC nanocomposites have been studied. SiC nanoparticles were varied from 1 to 5% by weight in a step of 1%. Aluminium fine powder and SiC nanoparticles were mechanically milled before mixing SiC nanoparticles into the melts. Hardness, tensile and compressive test results were enhanced with the addition of nanoparticles. Toughness, elongation and forgeability decreased with the incorporation of SiC nanoparticles. Hardness increased by 125%. The improvement of 41% in YTS and 45% in UTS and 603 MPa in compressive strength in case of A356/5%SiC nanocomposites were observed. To identify the involvement and presence of the SiC nanoparticles into the matrix alloy, fractured surfaces of the fabricated nanocomposites were examined using SEM with EDX spectrum. SEM micrographs disclosed the nature of the fractured mechanism. Proper distribution of SiC nanoparticles were attributed by SEM micrographs. The main constituents present in the nanocomposites were verified by EDX spectrum.

Fabrication and photoluminescence performance of SiC nanoparticles with different structure

ABSTRACTHighly dispersed β-SiC nanoparticles and core-shell structure nanoparticles were synthesized by sol-gel and carbothermal reduction methods, in which corn husks and tetraethoxysilane (TEOS) were respectively employed as carbon and silica precursors, with different masses of cobalt nitrate as additive. The SiC nanoparticles and core-shell structure nanoparticles have diameters of 20–80 nm. They are perfect candidates to study the structure effect of SiC nanoparticles on their optical properties. Photoluminescence properties of core-shell structure nanoparticles were different from those of traditional nanoparticles. The core-shell structure nanoparticles show an abnormal blue shift when the excitation wavelength moves from 290 to 330 nm, which is likely caused by core-shell structures and core-shell interface defects. A possible growth mechanism is proposed to interpret the synthesis process.

Effect of SiC nano-particles on microstructure and mechanical properties of the CoCrFeMnNi high entropy alloy

Abstract Novel metal matrix nanocomposites were designed exploring the CoCrFeMnNi high entropy alloy as a matrix and SiC spherical nanoparticles with a diameter of 20–50 nm as a reinforcement phase, and manufactured by mechanical alloying followed by hot isostatic sintering. After reaction at 1000 °C for 15 min the microstructure consisted of a matrix with a face centered solid solution of all elemental ingredients with traces of M 23 C 6 /M 7 C 3 carbides (where M = Cr, Fe, Co), σ-phase and SiC nano-particles distributed along grain boundaries of the matrix. Additions of 5 wt% of SiC nano-particles increased the room temperature compressive yield strength of the CoCrFeMnNi base from 1180 MPa to 1480 MPa, accompanied by a decrease in compressive strength and plasticity. The results are discussed in terms of mechanisms controlling the strengthening process in nano-composites with high entropy alloy matrix.