SiC Particle Size Research Articles

Effect of SiC Particle Size on Microstructure, Mechanical Properties, and Oxidation Behavior of HfB2–SiC Composites Prepared by Spark Plasma Sintering

Effect of SiC Particle Size on Microstructure, Mechanical Properties, and Oxidation Behavior of HfB2–SiC Composites Prepared by Spark Plasma Sintering

Mullite Reinforced SiC/Al2O3 Composites Prepared by Microwave Sintering Based on Green Manufacturing

In the preparation process of composites, the implementation of green manufacturing technology has an important impact on improving material properties and preparation efficiency. The adopting of green manufacturing technology not only greatly reduces the energy consumption but also effectively avoids the environmental pollution. Compared with the traditional material preparation process, the material preparation process for green manufacturing is a new concept and idea. Microwave sintering is such an efficient, clean, and pollution-free preparation process, so it is widely used in the field of material preparation. By microwave sintering, the mullite reinforced SiC/Al2O3 composites with different SiC particle size were prepared from the composite powders composed of SiC particles coated with SiO2, by a sol-gel method and Al2O3 particles. The effect of SiC particle size on the microstructure, bulk density, fracture toughness, flexural strength, and thermal shock resistance of SiC/Al2O3 composites was studied. The bulk density, fracture toughness, and flexural strength were evaluated by the Archimedes method, single-side notched beam method, and three-point bending method, respectively. The thermal shock resistance of samples was investigated through the combination of water quenching and three-point bending methods. The results showed that with the increase of SiC particle size, the bulk density, fracture toughness, and flexural strength of samples all increased first and then decreased. The bulk density, fracture toughness, flexural strength, and flexural strength retention of SiC(5 μm)/Al2O3 composites were better than those of other samples, which were 2.06 g/cm3, 1.98 MPa·m1/2, 63 MPa, and 60%, respectively. The better mechanical properties and thermal shock resistance of SiC(5 μm)/Al2O3 composites are due to the formation of bridging mullite whiskers between SiC and Al2O3 particles with large length diameter ratio. Therefore, the unique sintering mechanisms of size coupling effect and local thermal aggregation effect in microwave sintering were discussed. The research results can not only provide reference for the preparation process of mullite reinforced SiC/Al2O3 composites but also for the wide application of microwave sintering technology.

ДОСЛІДЖЕННЯ СТРУКТУРИ ТА ВЛАСТИВОСТЕЙ АЛЮМІНІЄВИХ СПЛАВІВ, МОДИФІКОВАНИХ ДИСПЕРСНИМИ КОМПОЗИЦІЯМИ

The effect of modifying dispersed compositions on the grain structure and mechanical properties of industrial aluminum alloys is studied. Aluminum alloys of the Al-Mg, Al-Mg-Sc systems were modified with dispersed SiC powder with a particle size of up to 200 nm. Calculated the amount of modifier to enter into the melt. The physicochemical properties of dispersed SiC were studied. The melting of alloys AL4S, 1570, 2219, AK9ch in the initial state and with the processing of SiC melts was carried out. The dependences of the particle size and amount of the modifier on the mechanical properties of the alloys are established. The mechanism of interaction of the modifier with the aluminum melt during crystallization is established. In industrial experiments, the most effective particle size of SiC was found to increase the σт of the AK9ch alloy from 115 to 260 MPa in the cast state. The optimal SiC content (0,10%) was determined to increase the σt of aluminum alloys.

Ti6Al4V/SiC Metal Matrix Composites Additively Manufactured by Direct Laser Deposition

Nowadays, research on additive manufacturing of Ti6Al4V alloy is growing exponentially but there are just a few studies about additive manufacturing of metal matrix composite components. In this work, highly reinforced Ti6Al4V matrix composites with SiC particles have been additively manufactured by direct laser deposition (DLD). Ti6Al4V powder and SiC particles have been deposited layer by layer to form an additive thin wall structure. The geometry, microstructure, and microhardness of the samples are strongly influenced by the laser scanning speed used during de fabrication process. In addition, the effect of the SiC increment in reinforcement concentrations and the influence of SiC particle sizes in the microstructure have been evaluated, and the reaction mechanisms have been established. The percentage of reinforcement measured is lower than expected due to the reinforcement-matrix reactivity that results in partially dissolved SiC particles and the formation of a TiC and Si5Ti3 ring around them. The size and number of particles and reaction products depend on the initial size and percentage of reinforcement and the DLD scanning speed. The higher the size and percentage of SiC particles and reaction products in the matrix, the higher the hardening effect of the composite matrix.Graphic

Effect of SiC particle size and weight percentage on power consumption during turning of AA7075/ SiC composite

Power consumption has become a serious issue in current manufacturing for numerous reasons such as, financial savings and environmental protection. The correct calculation of the power consumption for various machining processes remains a challenge. This paper presents an experimental investigation of the power consumption during the turning operation of AA7075/10 wt% SiC (particle size 10–20 μm), AA7075/10 wt% SiC (particle size 20–40 μm), AA7075/15 wt% SiC (particle size 10–20 μm) and AA7075/15 wt.% SiC (particle size 20–40 μm) composite. Machining of the AA7075/ 10 wt% SiC and AA7075/ 15 wt% SiC composites bars was done by using carbide insert CNMG 120404, 08,12EM, grade 6615 at various cutting parameters. Study displays impacts of cutting parameters such as cutting speed, depth of cut, feed rate and nose radius on power consumption during the turning operation of AA7075/SiC composites. Minimum power was consumed during the turning of 04 type of AA7075/SiC composites mentioned in this research, when turning was done at cutting speed of 90 m/min, feed of 0.15 mm/rev, depth of cut of 0.20 mm and nose radius of 0.40 mm. The novelty of this research is that it contributes to the practical features of composite machining knowledge by discovering relations between the effects of SiC particle size and weight percentage on the power consumption, and pertinent power consumption characterisation AA7075/ SiC composites.

Impact of SiC particle size upon the microstructure and characteristics of Ni-SiC nanocomposites

In order to deposit the Ni–SiC nanocomposites on Q235A steel substrates, magnetic pulse electrodeposition was employed in this article. Scanning electron microscopy (SEM), triboindenter in-situ nanomechanical testing, scanning probe microscopy (SPM), and X-ray diffraction (XRD) were used to assess the composites in terms of their compositions, microstructures, and microhardness. There were three specimens in total, with SiC particle sizes of 30, 80, and 200 nm, referred to as SN-30, SN-80, and SN-200 composites. With fine nickel grains and nanoparticles of SiC, SN-30 nanocomposites have fine, compact, and homogeneous architectures. There is a substantial impact of the size of SiC particles on the spectra of XRD for the nanocomposites. For SN-200 nanocomposite, the peaks of diffraction for SiC and Ni seemed to be high and sharp. SiC nanoparticle and Ni grain sizes in SN-30 nanocomposite were measured to be 34.4 and 381.3 nm, respectively. SN-30 and SN-200 composites have final depths of roughly 15.2 μm and 24.6 μm, accordingly. Following a subsequent investigation of the corrosion and wear characteristics of Ni-SiC nano-composites, the weight loss values of SN-30, SN-80, and SN-200 composites were calculated to be 1.01, 1.48, and 1.69 g, respectively, after corrosion testing for 24 h. During wear testing, however, just a few small pits were discovered on the SN-30 nanocomposite surface, indicating optimum wear resistance.

Absorbing oxygen carrier induces phosphorus enrichment in sludge: Preparation and screening

Phosphorus recovery from sludge is considered a feasible approach. By combining the oxygen carrier gasification technology and microwave heating, an absorbing oxygen carrier (AOC) is used in this study to successfully induce phosphorus enrichment in sludge char. The AOC, which is based on iron and supported on SiC, has been prepared via ultrasonic impregnation. The effects of preparation conditions (particle size of SiC and loading of iron) on the phosphorus enrichment characteristics, thermal reaction performance of the AOC and sludge, and the wave absorption performance of the AOC were investigated. The results show that the AOC prepared using a SiC particle size of 36 mesh and iron loading of 10% can achieve a phosphorus enrichment of 91.30% in the sludge char when the temperature of the microwave reactor is 600 °C. In the thermal reaction test, AOC can effectively increase the rate and depth of sludge gasification reaction in the medium- and high-temperature reaction stages. Iron-based is loading on the SiC surface and has a good wave absorption performance (RL = -16.28 dB; effective absorption width is 3.54 GHz). Overall, this study provides a new and effective approach for utilizing sludge.

Gas production from hydrothermal and radiolytic reactions at silicon carbide-water interfaces

The present work explored the surface reactions in SiC suspensions subjected to high temperature and 60Co-gamma irradiation, respectively. We observed for the first time the pH-dependent SiC dissolution by water at 300 °C and 10 MPa produces a substantial CH4, while the formation of another product H2 is decreased by the reaction time. On the other hand, the continuous H2 production from water radiolysis is greatly enhanced by the presence of an interface possibly due to the interfacial charge transfer processes. Both of the reactions are accelerated by the increased active surface contacts that are associated with the decreased SiC particles size from 250 nm to 50 nm and rising weight percentage from 3% up to 7%. The XPS, FTIR, SEM, and XRD data found little microstructure changes by gamma irradiation, but noticeable corrosive surface during hydrothermal reactions. The study pointed out that gas release is an important factor that should be considered when SiC is applied for LWR fuel assemble.

The local deformation behaviour of MMCs – an experimental study

AbstractThe local deformation behaviour of powder metallurgy metal matrix composites (MMCs) with two different SiC particle sizes and aging conditions are investigated and compared to the behaviour of the un-reinforced matrix. In situ tensile loading experiments are carried out in a scanning electron microscope. Images taken at different deformation stages are analysed by a system for local deformation measurement. It is found that even the pure matrix material deforms inhomogeneously, showing a shear-band pattern which is independent of the loading stage. The MMCs with coarse reinforcements deform mainly due to shear bands which are induced by fractured particles. The MMCs with small particles exhibit a shear-band pattern which is controlled by the particle arrangement. The fracture of small particles does not induce far-reaching shear bands and, therefore, these materials have a higher strength and ductility.

Structural and mechanical characteristics of ZA27-7 wt.% SiC composites produced by powder metallurgy techniques

Abstract This paper describes a study of the structural and mechanical properties of Zn-matrix composites discontinuously reinforced by 7 wt.% SiC particles of size 0.7 µm. Commercial Zn-rich Zn–Al –Cu (ZA27) alloy was gas atomized, the resulting powder was mixed with a SiC powder and hot compacted into cylindrical pellets. Metal powder and powder mixture were pressed at 230°C for 60 min, under a pressure of 170 MPa. The compressive strength testing was performed in the temperature range from 20°C to 170°C with a deformation rate of 2.4 × 10 –3 s–1. Detailed microstructure characterization of samples has been evaluated by optical and scanning electron microscopy.

Effect of SiC Particle Size on Properties of SiC Porous Ceramics

Effect of SiC Particle Size on Properties of SiC Porous Ceramics

Effects of SiC particle size on flexural strength, permeability, electrical resistivity, and thermal conductivity of macroporous SiC

In this study, macroporous SiC ceramics were fabricated via in situ liquid-phase bonding using an Al 2 O 3 –Y 2 O 3 –SiO 2 bonding additive at 1500 °C. The pore size of the ceramics was successfully varied from 7.8 to 45.5 μm by increasing the SiC particle size from 37.6 to 262.6 μm, without changing the porosity. The effects of the SiC particle size and pore size on the flexural strength, permeability, and electrical resistivity of the ceramics were investigated. The pore size and SiC particle size significantly affected the properties of the macroporous SiC. With an increase in the pore size and SiC particle size, the flexural strength and electrical resistivity of the ceramics decreased significantly, while the permeability and the thermal conductivity increased considerably. The porous SiC with a pore size of 45.5 μm and a porosity of 37.8% exhibited a high permeability of 21.2 × 10 −12 m 2 , relatively high flexural strength of 20.6 MPa, moderate electrical resistivity of 3.8 × 10 5 Ω cm, and high thermal conductivity of 66.4 Wm −1 K −1 .

The effect of particle size and mass ratio on the mechanical response of Al/PTFE/SiC composite with a 23 factorial design.

In order to study the effects of different SiC mass ratios, SiC particle sizes and Al particle sizes on the mechanical response of Al/PTFE/SiC, an experiment was conducted through the full 23 factorial design. The specimens were prepared by means of molding-vacuum sintering, while the mechanical response of the materials was measured through quasi-static compression. The regression models between failure stress, failure strain and various factors were established respectively and then verified through the analysis of variance (ANOVA) and residual analysis. Besides, the relationship between factors and response as well as that between factors were analyzed using response surface plots. According to the analytical results, the ultimate compressive strength of the material can be improved either by reducing the particle size of SiC and Al or increasing the mass ratio of SiC, while the ductility of the material can be enhanced by maintaining the interaction between SiC mass ratio and SiC particle size at high levels. The interaction effects are significant and can not be ignored, especially the interaction between SiC mass ratio and SiC particle size has an important impact on the mechanical responses, which shows that SiC has a greater influence than Al particles in the material system.

Effect of SiC Content and Particle Size on the Self-healing Property of Plasma-Sprayed Environmental Barrier Coatings

Effect of SiC Content and Particle Size on the Self-healing Property of Plasma-Sprayed Environmental Barrier Coatings

Effect of SiC Particle Size on the Strength and Stiffness of Porous Si3N4-SiC Composites Fabricated Via a Low-Temperature Sintering Process

Effect of SiC Particle Size on the Strength and Stiffness of Porous Si3N4-SiC Composites Fabricated Via a Low-Temperature Sintering Process

Heat Treatments Effects on the Fatigue Behaviors of Aluminum Nano-Composite Alloys

The fatigue is one of the major reasons for fracture of materials. Aluminum 7204 AA alloy with various heat treatments and (2.0) wt % of SiC nanoparticles were prepared by stir-casting method under rotating bending loading with ratio of stress (R= -1). The composite was strengthened by SiC particles size of) 10 (nanometre. The fatigue strength and life were obtained experimentally by the family of S-N curves for different heat treatments. The endurance limits (107cycles) for 7204 AA/ 2.0wt% SiC nano-composite fatigue strength as related to untreated nanocomposite was enhanced by 72 and 78.5% for T4 and T6, respectively.The improvement of fatigue properties is due to better spreading of SiC nanoparticles and increased porosity.

Studying the process of modification of lithium aluminum alloys

The effect of modification with dispersed compositions on the grain structure and mechanical properties of industrial aluminum alloys has been studied. Aluminum alloys of the Al-Si, Al-Mg-Sc, Al-Cu-Mn systems were modified with dispersed Mg2Si powder with a particle size of up to 200 nm. The amount of modifier to be added to the melt is calculated. The physicochemical properties of dispersed Mg2Si have been studied. Melting of the AMg6, 1570, 2219, AK9ch alloys in the initial state and with the treatment of Mg2Si melts have been carried out. The action of insoluble applications, isomorphic to aluminum, the similarity of the influence of soluble elements holds only when the amount of insoluble addition exceeds the number of crystals formed arbitrarily under the same conditions. Thus, with an increase in the amount of insoluble addition, in particular silicon carbide particles, the grain size first decreases and then remains constant. The mechanism of the influence of dispersed particles of magnesium silicide on the formation of the structure of hypoeutectic aluminum alloys during crystallization is that their bulk is pushed out by the crystallization front into the liquid phase and participates in the refinement of the structural components of the alloy. To determine the optimal amount of silicon carbide modifier, industrial melting and testing were performed on specimens that underwent heat treatment according to the T6 mode (quenching and artificial aging). The quality of cast aluminum alloys during modification depends on many factors: the nature of the dispersed phase, the temperature of the melt, and the modes of its mixing with the introduction of particles. Dependences of the particle size and the amount of the modifier on the mechanical properties of the alloys have been established. The mechanism of interaction of the modifier with aluminum melt during crystallization has been established. In industrial experiments, the most effective size of SiC particles for increasing the σm of the AK9ch alloy from 115 to 260 MPa in the as-cast state has been established. The optimal content of Mg2Si (0.10 %) for increasing the σm of aluminum alloys has been determined.

An investigation on thermal shock resistance of ZrB2-SiC composites

In this research, the effect of particle size of the SiC powder was studied on the thermal resistance. In this regard, initial SiC powder was prepared in three sizes of 25 μm, 45 nm, and 80 nm. The sintering of the composites was performed at three temperatures of 1600 °C, 1700 °C, and 1800 °C, as well as at three times of 4 min, 8 min, and 12 min under the constant pressure of 40 MPa. The thermal shock resistance of the sample was investigated through fast cooling in water. Moreover, the flexural strength of the samples was measured through the three-point method. The results showed that the thermal shock resistance is improved by declining the particle size of initial SiC from micro to nano in such a way that the amount of the critical T for the samples sintered at 1700 °C and 1800 °C reaches 510 °C and 590 °C. The flexural strength reaches the highest value (about 400 MPa) using nano scale SiC particles.

Improved thermal conductivity of form-stable NaNO3: Using the skeleton of porous ceramic modified by SiC

Corrosion and low thermal conductivity are considered as two great challenges for the application of salts-based phase change materials (PCMs). To address these problems, a novel skeleton, namely SiC modified diatomite-based porous ceramic, was prepared to develop form-stable NaNO3 salt. The results showed that a good wettability and chemical compatibility existed between SiC and molten NaNO3. Thermal conductivity of composite PCMs was found to be nearly linearly related with the concentration of SiC. 20% SiC added into the skeleton helped to enhance thermal conductivity of composites by 50%, benefited by the formation of a high thermally conductive heat transfer path. A smaller particle size of SiC contributed to a higher thermal conductivity of composites by increasing the heat transfer area between PCMs and skeleton. Form-stable NaNO3 (56.6%) that had a skeleton modified by 10% SiC (only 4.3% in composites) with particle size of 50 nm possessed a thermal conductivity of 2.06 W/(m·K) at 25 °C, which was 265% higher than that of pure NaNO3. Such composites also performed quite a good stability during the 500 thermal cycles, in terms of chemical compatibility, thermal conductivity, latent heat, phase transition temperature, and mechanical strength. Therefore, the novel composite PCMs exhibited a great application prospect in thermal energy storage.

Effect of SiC Particle Contents and Size on the Microstructure and Dissolution of SiC-Hydroxyapatite Coatings

Carbon/carbon composites, when used as bone implant materials, do not adhere well to the bone tissues because of their non-bioactive characteristics. Therefore, we electro-deposited SiC-hydroxyapatite coatings (with an ultrasound-assisted step) on carbon/carbon composites. We analyzed how the content and size of the SiC particles affected the structure, morphology, bonding strength and dissolution of the SiC-hydroxyapatite coatings. The hydroxyapatite coating dissolution properties were assessed by the released Ca2+ and the weight loss. The SiC-hydroxyapatite coating on naked carbon/carbon composites showed a more compact microstructure in comparison to the hydroxyapatite coating on carbon/carbon composites. The reasons for the changes in the microstructure and the improvement in the adhesion of the coatings on C/C were discussed. Moreover, the addition of SiC particles increased the binding strengths of the hydroxyapatite coating on C/C composite, as well as reduced the dissolution rate of the hydroxyapatite coating.