Silicon Carbide Particle Size Research Articles

Experimental Study on Microwave Pyrolysis of Decommissioned Wind Turbine Blades Based on Silicon Carbide Absorbents

The rapid expansion of the scale of wind power has led to a wave of efforts to decommission wind turbine blades. The pyrolysis of decommissioned wind turbine blades (DWTBs) is a promising technological solution. Microwave pyrolysis offers the benefits of fast heating rates and uniform heat transfer, making it a widely used method in various heating applications. However, there are few studies on the microwave pyrolysis of DWTBs, and pyrolysis characteristics under different boundary conditions remain unclear. In this paper, we investigate the pyrolysis characteristics of DWTBs by utilizing silicon carbide (SiC) particles as a microwave absorbent. The results demonstrated that, when the microwave heating power increased from 400 W to 600 W, the heating rate and pyrolysis final temperature of the material increased, resulting in a reduction in pyrolysis residual solid yield from 88.30% to 84.40%. At 600 W, pyrolysis gas components included C2H4, CH4, and CO, while the tar components included phenol and toluene. The highest degree of pyrolysis was achieved under the condition of an SiC particle size of 0.85 mm, with better heating performance, and the calorific value of the pyrolysis gas generated was 36.95 MJ/Nm3. The DWTBs did not undergo pyrolysis when SiC was not added. However, when the mass ratio of SiC to DWTBs was 4, the tar yield was 4.7% and the pyrolysis gas yield was 17.0%, resulting in a faster heating rate and the highest degree of pyrolysis. Based on this, an optimal process for the microwave pyrolysis of DWTBs was proposed, providing a reference for its industrial application.

Vat photopolymerization of silicon carbide strengthened alumina ceramic composites with honeycomb structure for heat insulation and oil/water separation

In this study, the effects of different silicon carbide (SiC) particle sizes on the viscosity and curing behavior of alumina (Al2O3) ceramic suspensions were thoroughly investigated. The findings revealed that increasing the size of SiC particles led to a noticeable decrease in the viscosity of the suspension. The Al2O3 ceramic suspension with 0.6 μm SiC powder demonstrated a shallower cure depth and wider excess width compared to the suspension with 1.0 μm SiC powder. Sintering tests demonstrated that the properties of the SiC–Al2O3 ceramics improved at higher sintering temperatures. Moreover, a high-performance honeycomb ceramic was successfully designed and fabricated with a porosity and compressive strength of 30.8 % and 188 MPa, respectively. Finally, the SiC–Al2O3 honeycomb ceramics were effectively applied in heat insulation and oil-water separation applications, demonstrating their remarkable capabilities.

Mechanical characteristics and deformation behavior of Al polycrystal reinforced with SiC particles

Molecular dynamics models are established to investigate the influence of silicon carbide (SiC) particle size and strain rate on the mechanical characteristics and deformation behavior of aluminum (Al)/SiC composite. The results show that the ultimate strength of the Al/SiC composite increases from 0.788 to 0.910 GPa as the SiC reinforcement particle size increases from 10 to 30 Å, due to load transfer effects and barriers to dislocation motion. Plastic deformation of Al/SiC composite decreases with increasing SiC particle size, manifested by a lower proportion of atoms subjected to high shear strain for larger SiC particles. The SiC particle size also influences the change in crystal structure during deformation, as shown by the larger particles better supporting the Al matrix in minimizing the dislocation movement. The study shows that the grain boundary and Al/SiC interface play a significant role in the mechanical properties of the composite by impeding the evolution of dislocation and stacking fault. Moreover, the higher strain rates lead to increased ultimate strength and flow stress due to a greater rate of deformation and energy storage. The distribution of shear strain in the composite shows concentrated deformation at the grain boundary, and the large shear-strain region decreases as the strain rate increases. Additionally, higher strain rate leads to more formation of hexagonal-close-packed and amorphous structures, increased dislocation density, and material failure.

An Ultra-Thin, Microwave-Absorbing Wear Layer for Pavement Deicing.

Microwave heating is widely employed in pavement deicing. However, it is difficult to improve the deicing efficiency because only a small part of the microwave energy is used and most of it is wasted. To improve the utilization efficiency of microwave energy and the deicing efficiency, we used silicon carbide (SiC)-replaced aggregates in asphalt mixtures to prepare an ultra-thin, microwave-absorbing wear layer (UML). The SiC particle size, SiC content, oil-stone ratio and thickness of the UML were determined. The effect of the UML on energy saving and material reduction was also evaluated. Results show that only a 10 mm UML was needed to melt a 2 mm ice layer within 52 s at -20 °C and rated power. In addition, the minimum layer thickness to meet the specification requirement (≥2000 με) of asphalt pavement was also 10 mm. SiC with larger particle sizes increased the temperature rise rate but decreased the temperature uniformity, instead increasing the deicing time. The deicing time of a UML with SiC particle size less than 2.36 mm was 35 s shorter than that of a UML with SiC particle size greater than 2.36 mm. Furthermore, more SiC content in the UML resulted in a higher temperature rise rate and less deicing time. The temperature rise rate and deicing time of the UML with 20% SiC were 4.4 times and 44% of those of the control group. When the target void ratio was 6%, the optimum oil-stone ratio of UML was 7.4%, and it had good road performance. Compared to overall heating, the UML saved 75% of power and SiC material under the same heating efficiency. Therefore, the UML reduces microwave deicing time and saves energy and material.

Influence of the Silicon Carbide Particle Size on Dielectric Characteristics, Thermal Conductivity, and Microwave Absorption of Pressureless-Sintered AlN–(20–50)% SiC Composites

Influence of the Silicon Carbide Particle Size on Dielectric Characteristics, Thermal Conductivity, and Microwave Absorption of Pressureless-Sintered AlN–(20–50)% SiC Composites

Fabrication and characterization of SiC-reinforced Al-4032 metal matrix composites

Aluminium metal matrix composites (AMCs) have become quite popular for light weight, low cost, and good workability. The present work reports the impact of silicon carbide (SiC) reinforcement on the physical, microstructural, and mechanical characteristics of Al-4032/SiC composites with 4, 6, 8% of SiC (particle size 54μm) fabricated through bottom pouring stir casting set-up. Density and porosity measurements of the AMC samples have been performed using the rule of mixture. The microstructure of the AMC samples has been analyzed using optical microscope (OM), x-ray diffraction analysis (XRD), and scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS). The mechanical properties, in terms of the ultimate tensile strength (UTS), elongation, micro-hardness, and impact toughness of the AMCs have also been measured according to American society for testing and materials (ASTM) standards. A maximum 1.52% increase in theoretical density, while a maximum 2.92% decrease in experimental density has been recorded for 8% reinforcement. The UTS, microhardness, and impact toughness of the AMC samples have been found to improve significantly owing to the addition of ceramic particles. The uniform distribution of SiC particles all over base Al-4032 matrix material has been noticed by SEM and OM for AMCs up to 6% reinforcement. The reinforcement particles tend to agglomerate beyond this composition.

Macro-hardness and corrosion behavior of silicon carbide or boron carbide reinforced AA5052 MMC

Metal Matrix Composites (MMCs) enhance the mechanical and tribological properties according to the composition of the particulate reinforcement of Silicon Carbide (SiC) or Boron Carbide (B4C) and AA5052 aluminum alloy matrix. The MMC samples were fabricated by stir casting method of the liquid processing route. The same weight percentages (5 wt. %) and same particle size (63μm) of both SiC and B4C particulates are used to develop two different MMC samples. The hardness and corrosion tests were conducted to estimate the enhanced properties of the fabricated composites. The macro-hardness test and the immersion corrosion test were carried out by using a Vickers hardness tester at an applied load of 5kgf in accordance with ASTM E92 and a 3.5% NaCl solution in accordance with ASTM G31, respectively. With the help of optical microscopy, the corroded surfaces were analyzed. The results obtained from the investigation show that AA5052/B4C MMC gives better hardness and AA5052/SiC MMC shows higher corrosion rate compared to the other two samples.

Wear resistance of working bodies of ground treatment machines strengthened by composite electrolytic coatings

The results of researches of influence of composite electrolytic coverings (CEP) on abrasive wear resistance of working bodies of tillage machines: paws of cultivators, disk harrows, plowshares are resulted in work. The influence of SiC (silicon carbide) filler particle sizes and their volume content in the nickel matrix on the tribological characteristics of QES applied to steel samples 45 was studied. QES with inclusions of silicon carbide fractions 28/20 and 50/40 microns, which have the least wear at all loads. The content of filler in such coatings is, respectively, 24 and 28 vol.%. Compared with galvanic nickel, such coatings have a reduction in wear of 13 and 5 times at loads of 20, 40, 60 N, respectively. Analysis of the test results showed that with increasing load, such as the coefficient of friction decreases and with increasing SiC particle size for the range of particle sizes of the filler 40… 60 μm, the coefficient of friction is minimal. For coatings with large filler particles (fraction 100/80) the coefficient of friction is higher. Thus, tribological studies show the prospects and effectiveness of CEP to increase the wear resistance of the working bodies of tillage machines.

Study on the Polishing Characteristics of the Rotating Cylinder-Based Magnetic Gel Abrasive Finishing

Magnetic gel abrasive finishing is a high-precision polishing method that uses magnetic forces to attract and restrain a gel abrasive, composed of aqueous slime gel, steel grits, and silicon carbon (SiC), for polishing workpieces. However, the magnetic adsorption performance of the gel abrasive will drop quickly when polishing non-ferromagnetic material such as stainless-steel or brass. Moreover, centrifugal force will push out the gel abrasive from the machining surface reducing the stability of polishing. Therefore, this paper developed a rotating cylinder-based magnetic finishing setup to allow the gel abrasive and workpieces to tumble and rotate together during the polishing process. To make the gel abrasive produce irregular and complicated movement paths for improving the polishing performance, this study first analyzed and compared the average surface roughness and removed material weight of workpieces using three kinds of motor operating modes; a unidirectional trapezoidal wave mode, a bidirectional sine wave mode, and a bidirectional trapezoidal wave mode. After identifying the best motor operating mode, the study further compared the polishing characteristics using several SiC particle and steel grit sizes. The experimental results showed that the rotating cylinder driven using a bidirectional trapezoidal wave could obtain better results for average surface roughness and removed material weight than the other two operating modes, while use of the larger steel grit size also obtained improved results. However, different silicon carbide particle sizes did not have a significant impact on the polishing characteristics.

The measurement threshold and limitations of an intra-oral scanner on polished human enamel

ObjectiveTo investigate the measurement threshold of an intra-oral scanner (IOS) on polished human enamel. MethodsThe optical performance of an IOS was compared to a gold-standard non contacting laser profilometer (NCLP), on a painted microscope slide, compared to increasing particle size of silicon-carbide papers (21.8–269.0 μm) and separately on polished human enamel with increasing step-heights. The enamel samples were randomised (n = 80) and scanned using the IOS and NCLP at increasing step-height depths (μm) (1.87–86.46 μm) and quantified according to ISO:5436-1. The measurement threshold of the IOS was determined using a custom designed automated lesion localisation algorithm, corroborated by Gaussian skewness (Ssk) and kurtosis (Sku) analysis, to assess the minimum step-height measured on each enamel sample. ResultsThe NCLP showed statistically increased Sq surface roughness for all silicon carbide particle sizes compared to the microscope slide, whereas, the IOS Sq roughness discriminated silicon-carbide particles above 68.0 μm compared to the glass slide (p ≤ 0.02). On polished enamel, the automated minimum detectable step-height measurable on each sample was 44 μm. No statistically significantly different step-height enamel lesion measurements were observed between NCLP and IOS above this threshold (p > 0.05). SignificanceThis study revealed the fundamental optical metrological parameters for the IOS, was step-heights above 44 μm and this reflects the data acquisition of the system. These results highlight the limitations of IOS used in this study, mandating further research to optimise the performance of other IOS systems, for measuring wear of materials or tooth wear on human unpolished natural enamel surfaces.

Effect of SiC reinforcement on the mechanical and tribological behaviour of Al6061 metal matrix composites

In the present work, the investigation of mechanical properties and specific wear rate of Al 6061 reinforced with silicon carbide (SiC) with different wt. % is carried out. The stir casting method was used for the fabrication of metal matrix composite and the SiC particle size of 25 µm was reinforced with two (C1-2.5% SiC C2-5% SiC) different weight percentages in Al6061. The SiC particles were preheated at 450 °C for 15 min and mixed with matrix at 850 °C. The mechanical properties such as tensile test, hardness, and dry sliding wear were conducted and the test specimen was prepared as per ASTM standard. The hardness value of 84 BHN was obtained for the C2 composite than the C1 composite (76 BHN). The tensile strength of the C1 composite was obtained in the order of 157 Mpa compare to the C2 composite (77 MPa). The C2 composite has shown a higher wear resistance than the C1 composite. The microstructure image of the composites was taken for ensuring the distribution of the reinforcement through SEM. The test results ensured that the reinforcement has a strong impact on the base materials, by using SiC in Al6061 can be tailored for a specific wear application.

Intensification of the fluidization performances of polypropylene by using microwave absorbent

Fluidization is an effective method to better help the transfer and conversion of fuel particles. In this study, intensification of the fluidization performances of polypropylene was experimentally investigated by using microwave absorbent. The fluidization performances of polypropylene (PP) were initially presented and the effects of microwave absorbent (SiC) particle size, mass ratio of SiC to PP, and fluidization velocity on the co-fluidization performances were studied and presented. The results showed that the PP load significantly increased the initial bed height whereas slightly increased the critical fluidization velocity and bed expansion ratio. Adding microwave absorbent (SiC) can effectively improve the fluidization performance of PP particles. The smaller SiC particles (0.25−1 mm) had better fluidization performances than the larger ones (1–1.5 mm and 1.5−2 mm). The mass ratio of silicon carbide to polypropylene decreased the critical fluidization velocity. Fluidization velocity significantly affected the co-fluidization performance. For the co-fluidization of polypropylene and silicon carbide in the designed fluidized bed, the recommended fluidization parameters were: (a) the particle size of silicon carbide of 0.25–1 mm, (b) the mass ratio of silicon carbide to polypropylene of 3:2, and (c) the fluidization velocity of 0.66 m/s.

Experimental fluidization performances of silicon carbide in a fluidized bed

A fluidized bed system was demonstrated and the fluidization performances of silicon carbide in the fluidized bed system were experimentally studied as to facilitate the further application of microwave-assisted fluidized bed. The results show that the smaller silicon carbide particles (0.25–1 mm) have better fluidization performances than larger ones (1–1.5, 1.5–2, 2–2.5 and 2.5–3 mm) due to the fact that the smaller particles are nearly spherical whereas the larger particles are irregular in shape (long and branched), and larger particles tend to form channels in fluidization. Fluidization velocity is too high, large bubbles will be generated to affect the uniformity of fluidized particles. The loading of fluidized particles should match that of the fluidized bed, and too low loading amount wastes the space of the fluidized bed, while too high loading amount will also produce large bubbles. For the fluidized bed system developed in this study, the suggested fluidization parameters were: (a) silicon carbide particle size of 0.25–1 mm, (b) fluidization velocity of 0.47–-0.71 m/s, and (c) silicon carbide particle loading of 40–50 g.

Study of silicon carbide dissociation into Fe and Fe C matrixes produced by die pressing and sintering

During the sintering process of self-lubricating steels, the dissociation of Silicon Carbide (SiC) in the iron matrix forms turbostratic graphite nodules which provide the lubricating properties of these materials. Previous works have explored the turbostratic nature of the graphite nodules and the influence of the SiC content in the microstructure and tribological properties of these materials, however, the thermodynamics and kinetics of SiC dissociation have not been fully explored yet. This study uses the versatility of die pressing to study the influence of particle sizes, sintering temperature and carbon content in the dissociation of SiC. The resulting materials were analysed by optical microscopy and scanning electron microscopy (SEM). The evolution of the size and morphology of pores and graphite nodules was investigated through image analysis software and simulations with the DICTRA® software were used to a better assessment of the kinetical aspects of SiC dissociation. Also, the thermodynamic influence of the particle size in the equilibria of the Fe–SiC system is discussed. Results indicate that SiC particle size rather than Fe/SiC size ratio governs the dissociation process, sintering temperature causes coalescence and rounding of pores as well as of graphite nodules. In addition, excessive activity of carbon in the system causes the precipitation of graphite flakes, which are not desired for technological applications.

Finite element investigation on the wave-particle interactions in ultrasonic inspection of SiCp/Al composites

While particulate-reinforced metal matrix composites are composed of two phase materials with dramatically different physical and mechanical properties, sound wave-particle interactions play an important role in their ultrasonic inspection tests. In the present work, we investigate the sound wave-particle interactions in silicon carbide (SiC) particle-reinforced aluminum (Al) matrix composites under the pulse-echo mode ultrasonic inspection by means of finite element simulations. Be consistent with experimentally observed real microstructures, the simulated SiC particles have polygon shapes and are randomly dispersed in the Al matrix. In particular, the sound wave-particle interactions are revealed, and their correlations with the A-scan signals are investigated. Furthermore, the effects of extrinsic pulse frequency and intrinsic SiC particle size on the ultrasonic inspection of the composites are addressed. Simulation results indicate that the interference of sound waves with heterogeneous SiC particles leads to more pronounced deflection, scattering and conversion of sound waves than the pure Al matrix, which in turn result in higher attenuation of sound waves in SiCp/Al composites. It is also found that the sound wave-particle interactions have a strong dependence on both pulse frequency and particle size.

Dual matrix and reinforcement particle size (SPS and DPS) composites: influence on mechanical behavior of particulate aluminum-SiC-Gr metal matrix composites

Aluminum powder reinforcing with ceramic particles makes an attractive composite material among Metal Matrix Composites (MMC). In the present research, powder reinforced composites were prepared by conventional powder metallurgy (PM) method, which comprises of powder blending, isostatic pressing and sintering process with different Silicon carbide particle sizes with varying percentages. Composite specimens were produced to net near shape for hardness, compression and tensile test as per the ASTM standard. Samples were sintered at 610°C for 120 minutes under argon atmosphere. The mechanical behavior of unreinforced Al5052 and Al7075 samples and dual amalgamation of Al5052 + Al7075 matrix along with SiC and Graphite reinforced composites prepared up to 18 weight %. These composite samples were produced using single or dual sized SiC powder particles. The study done to discern in which conditions the superlative properties would be attained. The most enhanced strength was obtained with the Specimen sample from batch 7 (Al5052+Al7075 blended with SiC 37µm of 18 weight % + Gr 6 weight %). Batch 7 constitutes of smaller size SiC particles with increasing percentage showed the most superlative result. The effective manufacture of aluminum based powder samples has influenced intensely by aluminum grade, SiC powder size and weight fraction. The overall results revealed that the Al-SiC-Gr considered as an exceptional composite combination where high strength to weight ratio are of a key significance

Effect of carbon nanotubes (CNTs) and silicon carbide (SiC) on mechanical properties of pure Al manufactured by powder metallurgy

In the present research, the effects of the size and amount of CNT and SiC particles on the mechanical properties of Al matrix composite were investigated. SiC of particle size 10μm, CNT 10–40nm, and Al powder of particle size less than 50μm and purity 99.99% were used. Composites of Al with 3, 6, 9 and 12wt.% SiC and 0.25, 0.5, 0.75, and 1wt.% CNT were manufactured by powder metallurgy technique by cold compaction and vacuum sintering. Relative density, hardness, compression and friction coefficient were studied. The results of scanning electron microscope (SEM) and optical microscope observations illustrated that the distribution of the reinforcing particles was uniform. Moreover, increasing the amount of SiC and CNT leads to decreasing the relative density and improving the hardness and compressive strength of Al–SiC and Al-CNT composites.

Multi-objective optimization of drilling of Al5059-SiC-2%MoS2 composites using NSGA-II

Abstract The drilling process is a broadly renowned conventional machining process which has the capacity to produce a hole on the components. The aluminum alloy of A15059 matrix is reinforced with the two different reinforcement particles such as silicon carbide (SiC) and molybdenum disulphide (MoS2). SiC particles are varied at three different sizes such as 10, 20 and 40 µm and three different weight percentages such as 5, 10 and 15%. MoS2 is added in all composites at a constant level of 2 wt%. The input process parameters considered for this investigation are spindle speed, feed rate, the particle size of SiC and weight percentage of SiC and output parameters such as metal removal rate (MRR) and temperature are studied. The present work is to optimize the drilling parameters of aluminium metal matrix composites using Non-dominated sorting genetic algorithm II (NSGA-II) technique. The drilling experiments are conducted based on Taguchi L27 orthogonal design. At the end, the optimal setting of drilling process parameters is found using NSGA-II that simultaneously maximizes MRR and minimizes temperature. The set of Pareto-optimal front offers flexibility to the manufacturing industries to select better drilling conditions depending on applications.

Silicon Carbide Films Prepared by Silicon Nitride Evaporation

Silicon carbide (SiC) films were synthesized on graphite substrates using silicon nitride (Si3N4) as silicon source at 1850°C, 1950°C, 2050°C and 2150°C, respectively. The characteristics of the synthesized films were analyzed by X-ray diffraction and scanning electron microscopy. The results show that the synthesis reaction can take place above 1850°C, and the SiC films were β-SiC. With the increase of temperature, the size of SiC particles increases, and when the soaking time is too short, the SiC particles are connected in a large area. Through the analysis of the films synthesis process, it is inferred that the growth of the SiC films belongs to the gas-solid growth mechanism.

Effect of manufacturing process parameters on the wear rate of Al 6061–Cu–SiCp alloy composites

In selecting the raw material for the production of machine parts, its wear resistance is considered a key parameter. Stir casting is a highly economical and effective technique for the manufacture of metal matrix composites. In the present research work, the tribological characteristics of an aluminum (Al) 6061 alloy composite reinforced with varying particle sizes of silicon carbide (SiC) (45, 53 and 63 μm) were investigated using a pin-on-disk wear-testing machine. Apart from this, the influence of pouring temperature and stirring speed during stir casting is also taken into account while characterizing the composite’s wear behavior. The analysis of variance test results indicate that the particle size of the silicon carbide reinforcement affects the wear rate of the composite samples. It was observed that the combined effect of stirring speed and pouring temperature significantly influences the wear rate of the test samples. Nevertheless, the combined effect of stirring speed and particle size of the ceramic reinforcement, as well as pouring temperature and particle size of silicon carbide, has no significance as far as the wear rate is concerned. The microstructural study of the worn samples was conducted using scanning electron microscopy analysis.