Distribution Of Silicon Carbide Particles Research Articles

Nanosecond laser processing and surface quality of SiC particle-reinforced AA2024 composite, homogeneous AA2024 aluminum alloy, and SiC: A comparative experimental study

This study performed comparative experiments on ablation behavior and surface quality obtained by nanosecond laser processing of silicon carbide (SiC) particle-reinforced 2024 aluminum alloy matrix composite (SiCp/AA2024), homogeneous SiC, and 2024 aluminum alloy. A nanosecond laser with a pulse fluence range of 0.68 ∼ 6.83 J/cm2 was used at irradiate samples of these materials, which were then ablated by various numbers of scanning passes (1 to 10) at a fluence of 6.83 J/cm2. The material melting could be achieved only for homogeneous AA2024. The ablation depth for SiC exceeded that of the composite, and the former could be ablated with a pulse fluence exceeding 3.42 J/cm2. The composite ablation threshold was higher than 4.10 J/cm2. Due to the thermal transition between the reinforcement and matrix, the melting threshold of the composite’s AA2024 matrix was lower than that of homogeneous AA2024 alloy. Moreover, the ablation threshold of SiC particles exceeded that of homogeneous SiC. The ablated surface roughness for the homogeneous material showed a sudden increase because of melting or oxidization, while that of the composite exhibited a gradual increase. For homogeneous SiC, oxidization accompanied by ablation and the accumulation of oxidization products on the surface deteriorated the laser pulse processing quality, especially in multipass scanning. In contrast, the dispersed distribution of SiC particles in the composite improved the composite’s machining feasibility.

Analisis Kandungan Silikon Karbida (SiC) Sebagai Filler Terhadap Peningkatan Kekerasan Pada Metal Matrik Komposit

Metal Matrix Composite is one of the metal composites that utilize aluminum alloy as a matrix in its fabrication. MMC has better specifications than the conventional materials it forms because it is light, ductile, with better hardness properties. The aluminum alloy as the matrix in this study has good mechanical properties but relatively low hardness values, especially type 2xxx aluminum containing Al-Cu or duralumin. By adding silicon carbide (SiC) ceramic content which acts as a filler in the manufacture of MMC it aims to increase the hardness value through a strengthening mechanism by analyzing the distribution of filler particles to the matrix. Using the sintering method with temperature variations that affect the mechanical properties of MMC. From the tests carried out the MMC specimens experienced an increase of 7.06% with the highest hardness value at 300oC sintering temperature of 71.6 HRB. With a SiC content of 14.42% Wt. Then it was observed using a Scanning Electron Microscope (SEM) that the distribution of SiC particles experienced an even distribution and bonded to the aluminum matrix thereby reducing porosity and increasing the hardness value of the MMC material.

Investigation of Mechanical Properties and Microstructure of AZ31-SiC-Graphite Hybrid Nanocomposites Fabricated by Bottom Pouring-Type Stir Casting Machines

In this study, a bottom pouring-type stir casting machine was used to create AZ31 magnesium alloy hybrid nanocomposites with varying weight percentages (0, 3, 5, and 7) of silicon carbide (SiC) and graphite (Gr) particles. Investigations have been made into the mechanical characteristics and microstructural distribution of manufactured hybrid nanocomposites. The outcomes demonstrate that the mechanical characteristics and uniform distribution of SiC and Gr particles are enhanced compared to those of the base alloy. In comparison to monolithic AZ31 alloy, microhardness, ultimate tensile strength (UTS), yield strength (YS), and compressive strength (CS) were raised by about 54%, 68%, 82%, and 107%, respectively. The presence of reinforced particles, the uniform distribution of particles, and the strong interfacial connection between the matrix and reinforcement all contribute to the improvement of mechanical properties. However, the addition of 7 wt. % SiC/Gr showed good mechanical properties compared to the base alloy. The microstructure of nanocomposites was analyzed using a scanning electron microscope (SEM), and particles were described using energy-dispersive spectroscopy (EDS).

Differentiation in the SiC Filler Size Effect in the Mechanical and Tribological Properties of Friction-Spot-Welded AA5083-H116 Alloy

Ceramic reinforced friction stir spot-welding (FSSW) is one of the unique welding techniques used to fabricate spot joints. This study is intended to investigate the effect of reinforcement additive particle size in achieving higher weld strengths. AA5083-H116 aluminum alloy plates were welded with nano- and micro-sized silicon carbide (SiC) particles. Investigations of the weld joints prepared using a tool rotational speed of 1300 rpm, tool plunge rate of 25 mm/min, and dwell time of 10 s revealed that the lap shear tensile strength and hardness of the nano-SiC particles added to aluminum joints were higher than those of the micro-SiC particles added to joints. In particular, the nano-SiC particles provided 29.6% higher strength and 23.3% higher hardness than the unfilled FSSW. The uniformly dispersed fine SiC particles in the processed zone provided more nucleation sites for the re-precipitation of new grains and the precipitates in the aluminum matrix. The X-ray diffraction results confirmed that there was no evidence of a new phase (intermetallic compounds). Reinforcement of SiC particles significantly enhanced the wear characteristics, as well (26.3%). Field emission scanning electron microscopy (FESEM) evidenced the uniform distribution of SiC particles in the weld nugget zone. In addition, the fractography of the samples is presented and discussed.

Evaluation of laser texturing in fabricating cut-resistant surfaces for protective gloves

The aim of the study was to evaluate the effects of laser texturing of coated textile materials on their cut resistance. The investigated material was an aramid knitted fabric coated with a polymer layer made of an acrylic-styrene dispersion functionalized with particles of silicon carbide (SiC). The distribution of SiC particles in the coating microstructure was assessed on the basis of microscopic observations (scanning electron microscopy). The coating was laser textured, and then the cut resistance of the assembly was determined using a rectangular blade. The findings showed that laser texturing improved the cut resistance of the tested materials, causing a fourfold increase in that parameter as compared to non-modified textile materials. This fact may improve the safety of workers wearing protective gloves in terms of cut protection.

Mechanical properties and corrosion behavior of a friction stir processed magnesium alloy composite AZ31B–SiC

Abstract The optimization of friction stir processing (FSP) parameters of magnesium alloy composite (AZ31B–SiC) based on orthogonal test was researched. The results show that the distribution of silicon carbide (SiC) particles, microhardness, tensile property, and fracture mode are greatly affected by the change in process parameters. The results show that the composite was made with a rotating speed of 750 rev·min−1, a traversing speed of 30 mm·min−1, and a processing time of three; the distribution of SiC particles is even, the microhardness difference of composite is small, the tensile property is better, and the ductile fracture is the main fracture mode. Besides, the existence of SiC and the number of FSP have a certain influence on the corrosion performance of the magnesium alloy composite (AZ31B–SiC), and the corrosion resistance of the FSP sample is obviously better than that of the AZ31B magnesium alloy.

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.

Manufacturing of gradient Al/SiC composite wire by friction stir back extrusion

In the current research, the friction stir back extrusion (FSBE) process as a novel method was used to fabricate the gradient AA6063/SiC composite wires. The scanning electron microscopy equipped with EDS analysis was utilized. To investigate mechanical properties, hardness and tensile tests were used. The results revealed that the distribution of SiC particles in the matrix is dependent on volume fraction. Particle distribution of AA6063/6% SiC sample was uniform while that of AA6063/12% SiC and AA6063/18% SiC was gradient. Gradient distribution had an important effect on the mechanical properties of composites. The tensile strength of all composite samples was improved so that the tensile strength of the Al/12% SiC composite became 2 times greater than that of the base material. Interestingly, the elongation of Al/12% SiC composite slightly increased compared to the base metal. This was due to a unique gradient distribution of silicon carbide particles in the aluminum matrix. Generally, the presence of the SiC particles caused to significant improvement of mechanical properties compared to the base metal.

Numerical and experimental determination of optical properties and thermal conductivity of ceramic composites based on fumed silica and silica fiber

The thermal insulation material composed of fiber-reinforced fumed silica (in the raw and opacified with silicon carbide, zirconia or titania powders) was produced and analyzed. Optical properties (scattering and absorption coefficients) were experimentally examined in the spectral range of 0.9 – 4.7 µm by the solution of the inverse problem of radiative transfer. The inverse problem was based on the invariant embedding equation and the measured spectral directional-hemispherical reflectance. The effect of silicon carbide opacifier addition on the optical properties, effective and radiative thermal conductivity was estimated. The calculated radiative thermal conductivity of thermal insulations with various volume fractions of SiC opacifier was compared to the one deduced from the effective thermal conductivity using the calorimetric technique of conductive and radiative components separation. The effective thermal conductivity was measured by the quasi-stationary technique in the temperature range of 373 – 1173 K. The results of the inverse problem solution were compared to the calculations based on the Mie theory and the measured size distribution of silicon carbide particles. The experimental scattering coefficient was shown to be smaller than the calculated one. At the same time, absorption coefficients demonstrated mutual consent. Possible uncertainties in SiC powder size and the complex refractive index of the basic material were considered as a probable explanation of the obtained results. The size distribution of SiC opacifier was numerically optimized to obtain as low Rosseland mean radiative thermal conductivity as possible. The influence of the opacifier chemical composition was analyzed by collating radiative thermal conductivity deduced from the measured effective thermal conductivity to ones calculated using Mie theory. Finally, the effect of Fe2O3, Si3N4, TiO2, graphite, ZrO2, TiN, TiC, AlN opacifiers was numerically analyzed using Mie theory. Compounds based on titanium and an iron sesquioxide were shown to be promising opacifiers for high temperature applications.

Effect of tool diameter ratio on the microstructural characteristics of a solid-state processed aluminum based metal matrix composite

Abstract Stir cast aluminum based metal matrix composites (MMCs) with silicon carbide (SiC) reinforcement particles consist of cast product dendrites and large agglomerated reinforcements. The agglomeration of SiC particles creates a difference in properties in the composite system. Friction stir processing (FSP) is used to overcome the uneven distribution of SiC particles in the aluminum matrix. The friction stir processed (FSPed) microstructure is significantly influenced by the process parameters used for processing. In FSP, the effect of the tool diameter ratio (tool shoulder diameter to pin diameter) on material flow, material mixing, material consolidation is more predominant than other parameters. Hence, a perfect combination of shoulder diameter to pin diameter is required to produce sufficient material flow. In this investigation, the tool diameter ratio is varied from 2.0 to 4.0 for processing composite material and thus FSPed zones were subjected to micro structural characterization. It was concluded that a tool diameter ratio of 3.0 yielded a defect free stir zone with higher hardness compared to other ratios.

Fabrication and processing of aluminum alloy metal matrix composites

ABSTRACT The present article demonstrates the procedure for fabrication of aluminum alloy 2014 based metal matrix composites having particulates of silicon carbide as reinforcement. Using the stir casting route, three different compositions of aluminum alloy metal matrix composites were fabricated. Microstructure of as-cast composites revealed a homogeneous distribution of silicon carbide particles along with few agglomeration and casting defects. Friction stir processing was performed to avoid such agglomeration and casting defects present in as-cast composites. The influence of friction stir processing parameters, that is, rotational speed and transverse speed on metallurgical properties, was investigated. Two combinations of rotational speed and transverse speed were considered: (i) 270 rpm and 78 mm/min and (ii) 190 rpm and 50 mm/min, respectively. As a result of friction stir processing, the microstructure of processed composites revealed the presence of fine silicon carbide particles along with the magnificent reduction in grain size. Composites processed with a rotational speed of 270 rpm and transverse speed of 78 mm/min were found to have higher grain refinement and as a result of this, the enhancement in microhardness was also observed. Except for a few cases, the average microhardness of all processed composites under both processed conditions was still lower than that of as–cast composites.

ENHANCED MICROSTRUCTURE AND MECHANICAL PROPERTIES OF SIC PARTICLE REINFORCED ALUMINIUM ALLOY COMPOSITE MATERIALS

Aluminium6061 alloy composites containing various volume fraction (0-25%) Silicon Carbide (SiC) particles were prepared by stir casting method. In the current study, microstructures and mechanical properties of cast silicon carbide (SiC) reinforced aluminum matrix composites (AMCs) were investigated. Optical microscopic examination, SEM, tensile strength test, hardness test, and elongation test were carried out. The results showed that the addition of SiC reinforcements in aluminum6061 matrix increased hardness and tensile strength however, decreased elongation at 25% SiC reinforced AMC. Hardness and tensile strength were observed to be are maximum at 25% SiC and elongation is minimum at 25% SiC. Microstructural observation confirmed clustering and homogeneous distribution of SiC particles in the Al6061 matrix.

Influence of SiC Content on Microstructure and Tribological Properties of Friction Stir-Processed SiC/AA5083 Surface Composites

The present work aims to produce silicon carbide (SiC) particles-reinforced AA5083 surface composites through friction stir processing (FSP). The influence of SiC content on the microstructure and tribological properties of the friction stir-processed (FSPed) AA5083/SiC surface composites was investigated. The results reveal that the distribution of SiC particles within the stirred zone was homogeneous, irrespective of location, and SiC particle volume fraction. Good SiC/AA5083 interfacial bonding was obtained for all surface composites with refined grains. Electron backscattered diffraction results revealed that the stir zones comprised dynamically recrystallized, fine-grained, and equiaxed microstructures. Transmission electron microscopy revealed that dislocations rearranged to form high-angle grain boundaries upon dynamic recrystallization. The worn surface showed that an increase in SiC volume fraction transforms the wear from severe plowing, and delamination to light abrasive wear. The surface composites showed a substantial decrease in wear rate with an increase in SiC volume fraction due to the homogeneous distribution of SiC particles, grain refinement, and improved hardness. The wear debris of AA5083 alloy showed large flakes as a sign of severe plastic deformation whereas, surface composite samples comprised of fine wear debris.

Effects of Silicon Carbide (SiC) Reinforcement on the Microstructure and Mechanical Properties of Laser Deposited Al-Sn-SiC/Ti-6Al-4V Composite Coatings

Titanium and titanium alloys have a large array applications attributed to its low density, good corrosion resistance and high specific strength. Damage to the surface can be improved by surface modification for extended application. Direct laser metal deposition (DLMD) technique can be used to address the limitations associated with titanium alloy. This is mostly achieved by integration of reinforcement materials into the main matrix to form coating. Thereby inducing microstructural changes to the material. The morphology and also the hardness property of the various composite coatings were examined. The hardness of the composite coating was found to range between 450.64 and 638.22 HV, and the hardness obtained for 10% SiC reinforcement coating was 638.22 HV. For all the coatings, the hardness was established to be much higher than that of the substrate, which was averaged 304.21 HV. Hardness value increases with increase in SiC content. The enhanced hardness values were due to refined grains and intermetallics in the microstructure of the coatings. Moreover, the highest tensile and yield strengths was found at 10 wt.% SiC due to the uniform particle dispersion that can impede dislocation movement. The uniform distribution of SiC particles in the Al-Sn matrix had a good effect on its mechanical properties.

Studies on friction stir processing parameters on microstructure and micro hardness of Silicon carbide (SiC) particulate reinforced Magnesium(Mg) surface composites

Friction stir processing (FSP) is promising as a capable method for producing surface composites in aluminum and magnesium-based alloys. In FSP a specifically intended rotating cylindrical tool that includes of a pin and shoulder that have dimensions relative to the plate thickness. The pin of the rotating tool is forced into the material and the shoulder comes into contact with the surface of the sheet, and then pass through in the desired direction. The present work focused to fabricate Silicon carbide (SiC) particulate reinforced Magnesium (Mg) surface composites. The effect of FSP parameters such as tool rotational speed, processing speed and wt % SiC on microstructure and micro hardness was investigated. A groove was contrived on the 6mm thick Mg plates and packed with SiC particles. FSP was carried out using Taguchi’s L9 orthogonal array. Scanning electron microscopy and XRD were employed to study the microstructure of the fabricated surface composites. The results indicated that the selected FSP parameters significantly influenced the area of surface composite, distribution of SiC particles and microhardness of the surface composites.

Stir Casting Process Simulation by Computational Fluid Dynamics for uniform Nano particles distribution in Al Semi Solid Metal

In this present work is to study and simulate the stir casting process to achieve uniform particle distribution at different heights in the tank. In the process, the percentage of volume fraction at five different locations was studied as the stirring speed and blade angle were changing. Other stir casting process parameter that is viscosity, stirring time is maintained constant. In this work a simulation study was conducted to investigate the effect of stirring speed and blade angle on the volume fraction of the Nano particles at different locations. The results of the simulation it is concluded 300 rpm stirrer speed and 30 degrees Blade Angle is more effective in all locations. The time taken to achieve uniform particle distribution. Blade angle and speed of stirrer played a significant role in distribution of silicon-carbide particles in aluminum semi solid metal (SSM).

Microstructure and wear behavior of AA6061/SiC surface composite fabricated via friction stir processing with different pins and passes

In this investigation, the effects of pin geometry and number of passes on macrostructure, microstructure, wear rate and also microhardness profile of 6061-T6 aluminum alloy surface composites fabricated via friction stir processing (FSP) were discussed by reinforcement particles of silicon carbide (SiC). The results show that after each FSP pass, a modify distribution of SiC particles is acquired and the increase in the number of passes reduces the average grain size in stir zone (SZ). Furthermore, it is discovered that pin geometry and pass number play a dominant role in the grain size of SZ and distribution of SiC particles in SZ. It is found that after each FSP pass, wear rate is improved due to the uniform distribution of SiC particles in surface of Al/SiC composite. Additionally, the results show that the square pin and smooth (straight) cylindrical pin have the highest and lowest resistance to wear, respectively.

Friction Stir Processing Strategies for Uniform Distribution of Reinforcement in a Surface Composite

Friction stir processing (FSP) is an important technique for preparing surface composites. Fabricating defect-free surface composites with uniform particle distribution by FSP is a challenging task. In this study, silicon carbide particles reinforced AA5083 alloy surface composites was fabricated using different FSP strategies including variation in process parameters, dual-tool processing and tool offset overlapping. Material flow of the processed material with reinforcement particles demonstrated that the distribution of particles was influenced by the stirring action of the probe as well as the extrusion of the plasticized material due to the movement of the tool. Process parameters, particularly rotational speed, showed a dominant influence on the distribution of silicon carbide particles.

Influence of Ni-P Coated SiC and Laser Scan Speed on the Microstructure and Mechanical Properties of IN625 Metal Matrix Composites

Nickel based Inconel-625 (IN625) metal matrix composites (MMCs) were prepared using pre-heated nickel phosphide (Ni-P) coated silicon carbide (SiC) reinforcement particles by Direct Metal Laser Sintering (DMLS) additive manufacturing process under inert nitrogen atmosphere to obtain interface influences on MMCs. The distribution of SiC particles and microstructures were characterized using optical and scanning electron micrographs, and the mechanical behaviours were thoroughly examined. The results clearly reveal that the interface integrity between the SiC particles and the IN625 matrix, the mixed powders flowability, the SiC ceramic particles and laser beam interaction, and the hardness, and tensile characteristics of the DMLS processed MMCs were improved effectively by the use of Ni-P coated SiC particles.

Sintered Frictional SiC-Reinforced Cu-Base Composites

Lead-free frictional materials are important components in safety and power transmission parts of automobiles. In order to avoid using lead-containing friction modifiers, non-toxic ceramic particles are considered to be used as reinforcements. In this research work, copper-based friction materials have been developed by using press and sinter method. Pre-alloyed bronze (Cu-10Sn) powder was admixed with iron (Fe), graphite (C) and varied amounts of silicon carbide (SiC) powders. The admixed powders were compacted into disc-shape samples, which were then sintered at different temperatures in the range of 800-950 °C. It was found that sintered density and hardness of the sintered copper-based friction materials reduced with increasing SiC content. Microstructures of the sintered materials showed inhomogeneity due to uneven distribution of coarse Fe and SiC particles. The coarse SiC particles also prohibited bonding between metal powder particles. However, the sintered materials showed high room-temperature friction coefficients, which were in the range of 0.50-0.90, particularly the materials containing 4 wt. % of SiC particles.