SiC Addition Research Articles

The Effects of Additives, Particles Load and Current Density on Codeposition of SiC Particles in NiP Nanocomposite Coatings

In this study, electrodeposition of NiP composite coatings with the addition of SiC 100 nm was carried out on low carbon steel studying the effect of additives (sodium dodecyl sulfate, saccharin), particles load (10 or 20 g/L) and current density (1, 2 and 4 A/dm2). As a benchmark, coatings from an additive-free bath were also deposited, despite additives being essential for a good quality of the coatings. The coating’s morphology and composition were evaluated by scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS). It was shown that by addition of sodium dodecyl sulfate (SDS), pure NiP coating with a higher P content was achieved, and their morphology changed to nodular. SDS also reduced the codeposited fraction of SiC particles, while saccharin increased it. SiC loading and current density had less impact respect to the additives on codeposition of SiC particles. Finally, the microhardness of NiP coatings did not increase linearly by codeposition of SiC particles.

Utilization of SiC and Cu Particles to Enhance Thermal and Mechanical Properties of Al Matrix Composites.

In this work, SiC and Cu particles were utilized to enhance the thermal and mechanical properties of Al matrix composites. The ball-milling and cold-compact methods were applied to prepare Al matrix composites, and the uniform distribution of SiC and Cu particles in the composite confirms the validity of our preparation method. After characterizing the thermal conductivity and the compressibility of the prepared composites, results show that small particles have a higher potential to improve compressibility than large particles, which is attributed to the size effect of elastic modulus. The addition of SiC to the Al matrix will improve the compressibility behavior of Al matrix composites, and the compressibility can be enhanced by 100% when SiC content is increased from 0 to 30%. However, the addition of SiC particles has a negative effect on thermal conductivity because of the low thermal conductivity of SiC particles. The addition of Cu particles to Al-SiC MMCs could further slightly improve the compressibility behavior of Al-SiC/Cu MMCs, while the thermal conductivity could be enhanced by about 100% when the Cu content was increased from 0 to 30%. To meet the need for low density and high thermal conductivity in applications, it is more desirable to enhance the specific thermal conductivity by enlarging the preparation pressure and/or sintering temperature. This work is expected to supply some information for preparing Al matrix composites with low density but high thermal conductivity and high compressibility.

Studies on the Fischer-Tropsch synthesis over RuCo/SiC-Al2O3 structured catalyst

RuCo/SiC-Al2O3 catalysts were with enhancing thermal conductivity for the Fischer-Tropsch Synthesis (FTS) were designed and manufactured. The SiC-Al2O3 support was extruded by Lab scale extruder and then foamed by the marumerizer. Catalysts were prepared by an incipient wetness impregnation method. All the prepared catalysts were characterized by SEM-EDX, XRD, TPR, TPD, XPS, ICP and N2-physisorption techniques. The catalytic performance was evaluated at T = 210–230 °C, P = 20 bar and GHSV of 1,000 h−1 in a fixed bed reactor system. The CO conversion over RuCo/nSiC-Al2O3 catalysts was increased by 10% compared to RuCo/Al2O3 catalyst at 210 °C. Furthermore, the selectivity of methane was similar or less than RuCo/Al2O3 catalyst. It was shown that the CO conversion increased with increasing the SiC content from 5 to 15 wt%, and then decreased. The RuCo/15SiC-Al2O3 catalyst showed higher CO conversion than other catalysts under the tested conditions. This is because the 15 wt.% SiC addition ratio is the most advantageous between thermal conductivity improvement and aggregation of cobalt particles.

Mechanical and tribological characterization of aluminum metal matrix composite reinforced with micro ceramic particles (TiB2/SiC)

Abstract In this work, the effect of addition of TiB2, SiC as secondary particles on the microstructure, mechanical and tribological properties of the Al6061 MMC has been studied. The wear rate of the composite specimens has been tested using a pin on disc configuration under normal loads of 10, 20 & 30 N. Microstructural characterization was carried out for the above prepared composites to ensure homogeneous distribution of particles. The images of scanning electron microscopy reveal a uniform distribution of TiB2 particles in the Al MMC. The X-ray diffraction analysis reveal the dispersal of SiC particles and Mg2Si inter metallic compound phases in the aluminum matrix. The hardness and tribological properties of cast Al alloy with TiB2 were compared with Al alloy with SiC addition.

The Doping Effects of SiC and Carbon Nanotubes on the Manufacture of Superconducting Monofilament MgB<sub>2</sub> Wires

MgB2 superconductor is a superconductor with a critical temperature of around 39K and has the potential to replace Nb3Sn and NbTi as superconducting coils to produce high magnetic fields. In this study, monofilament wires have been made to analyze the doping effect of SiC and Carbon Nanotubes (CNT) in its manufacture using Powder-In-Tube (PIT) method. Stainless Steel (SS-316) tube was used as a tube filled with powders of starting materials of Mg, B, SiC and CNT. A total of 8 samples were prepared with variations in the addition of SiC, and CNT as much as 5, 10, and 15 wt %, and also the variations in the addition of Mg composition by 0 and 10 mol % from normal stoichiometric values. The samples were rolled and sintered at 800°C for 3 hours. The samples then were analyzed using SEM (Scanning Electron Microscopy) to analyze the surface morphology, XRD (X-Ray Diffractometer) to analyze the formed phases and crystal structures, and then resistivity versus temperature using cryogenic systems to analyze their superconductivity properties. Based on the results of the XRD analysis, the MgB2 phase is the major phase in the samples and the SiC doping causes the formation of minor phases of Mg2Si and Fe3C. The addition of SiC causes a decrease in crystalline properties of the MgB2 phase due to reaction with SiC, while the addition of CNT does not cause the formation of a new phase. Based on the results of the analysis of resistance versus temperature, it is seen that the addition of SiC causes a decrease in TC value. While the addition of CNT causes the improvement in the nature of superconductivity, but it also causes the decrease of its TC values.

Air Jet Erosion Study on Stir Casted Metal Matrix Composite Aluminum-SiC

For equipment that operates in high-speed abrasive media, erosion will be the major factor for its failure. Metal Matrix Composite (MMC) Aluminum-Silicon Carbide has been developed for improving the lifetime for such application.In this research, MMC Al-SiC has been made using Al-7075 scrap with 5%, 10%, and 15% SiC powder addition. This MMC was manufactured using stir casting technique with 1% Magnesium addition. Optical metallography has been done to know the SiC distribution homogeneity. Erosion resistance of the MMC was studied using Air Jet Erosion Test with Alumina powder as abrasives.The microstructural study showed that MMC Al-SiC has been successfully manufactured although the SiC particle distribution has not been fully homogeneous yet. Air Jet Erosion Testing revealed that the addition of 5% SiC powder was optimal in increasing its erosion resistance. The SiC addition from 10 to 15% did not improve its erosion resistance significantly.

The Effect of Variation of Nano SiC Reinforcement Particle Addition to Mechanical Properties of Mg/Nano SiC Composite by Stir Casting Method

Composites are advanced material which is being developed that contains of two materials or more in order to improve the mechanical properties. Magnesium composite is a suitable material beside aluminium and its alloy to be applicated as vehicle body structure due to its lightweight and its low density. Thus, the vehicle body structure with lightweight and good mechanical properties can be achieved. In this research, magnesium composite is fabricated by mixing magnesium as composite matrix and nano SiC as reinforcement particle with the variation of the volume fraction 0.05 %vf, 0.10 %vf, 0.15 %vf, 0.20 %vf, and 0.25 %vf with stir casting as fabrication methods. To characterize the composite product, several testing were done, which were chemical composition characterization, metallographic observation, SEM-EDS characterization, XRD characterization, hardness testing, wear testing, and impact testing. The result of this research shows that with nano SiC addition as reinforcement particle will increase mechanical properties of magnesium composite. The best mechanical properties of magnesium composite is shown by the addition of 0.15 %vf nano SiC. The result shows the brinnel hardness number of this composition is 39 HB and 0.0052 mm3/m wear rate. Mechanical properties of magnesium composite are increased due to several strengthening mechanism such as grain size reduction and Orowan strengthening mechanism.

Effect of SiC addition on the microstructures and wear resistance of ZrB2-ZrC reinforced Ni-based composite coatings

ZrB2-ZrC reinforced composite coatings with addition of SiC were prepared by plasma cladding. Effects of the addition of SiC on the microstructure, microhardness, and wear resistance of the fabricated coatings were investigated. Results showed that the coatings were mainly composed of ZrB2, ZrC and γ-Ni phases. The size of ceramic particles in the coating was affected by the SiC addition. With 20 wt% SiC addition, the microstructure of the coating was refined significantly. Compared with the coating with no SiC addition, the microhardness and wear resistance for coatings with 20 wt% SiC addition increased by about 17% and 65%, respectively. Measurement results of the wear volume verified the positive effect of SiC on the improvement of wear resistance.

Thermal stability under laser heating of hot-pressed (Hf1-X ZrX)B2/SiC powder mixtures obtained by mechano-synthesis

The paper studied ultra-refractory (Hf1-X ZrX)B2/SiC ceramics fabricated by hot-pressing (HP) of mechano-chemically assisted precursors synthesis, and tested their thermal stability under laser heating. Fully dense materials were obtained after HP. Microstructures of the sintered materials were analyzed by XRD and SEM-EDS, while 4-pt flexure strength in air at room temperature up to 1773 K was measured. The thermal stability was tested using a diode laser source. A SiC-free fully dense ZrB2 ceramic was used as benchmark to identify the potential of the laser heating technique and separate the effects related to the addition of SiC into a diboride ceramic matrix. Infrared thermo-camera and 2-color pyrometer provided the real-time variation of the surface temperature vs time. For surface temperatures below 1900 K reached by the SiC-containing samples, SiC acted as a key player and provided excellent protection to the diboride matrices against oxidation: extensive post-test microstructural analyses documented this response.

Hydrogen production from partial oxidation of propane: Effect of SiC addition on Ni/Al2O3 catalyst

One of the most attractive routes for hydrogen production for fuel cell applications is partial oxidation of hydrocarbons. However, exothermic partial oxidation reaction tends to cause local overheating of the reaction bed therefore reducing catalytic activity. In this study, hydrogen production by partial oxidationofpropane over Ni/Al2O3 based catalyst with the addition of SiC was experimentally investigated. Both packed bed mixing and bulk doping methods were introduced to study the effect of SiC for its high thermal conductivity and high temperature stability. The as-prepared samples were characterized by a variety of measurements. Due to the high temperature stability of SiC particles in the bulk regions, stacking dual porous-like structures were formed after calcination by doping SiC into Ni/Al2O3 with certain ratios. From the results, local overheating of the catalyst bed generated by the exothermic reactions was relieved by SiC addition for both cases. Ni/Al2O3-SiC (30 wt% SiC) catalyst performed a higher hydrogen production of 236 μmol/gcat.s and kept stable for 20 h at 600 °C compared to mechanical mixing method. Aggregation of Ni content and carbon deposition of the spent catalyst of SiC-containing catalysts were reduced compared to Ni/Al2O3. As can be seen from the morphological and non-isothermal kinetics, the carbon deposited on Ni/Al2O3-SiC catalyst that caused catalyst deactivation was more easily activated for removal due to SiC content with high thermal conductivity.

Effect of SiC particle additions on the corrosion resistance, thermodynamic stability and surface morphology of Mg–Al alloy in sulphate and chloride media

Application of magnesium materials continues to grow due to their high specific strength and excellent castability. However, low corrosion resistance limits their application in aqueous electrolytes. Understanding their corrosion behaviour is key to the improvement of their corrosion resistance. The effect of SiC at specific weight content on the corrosion polarization behaviour, surface morphology and thermodynamic stability of Mg–Al alloy in 0.05 M H2SO4 and 3.5% NaCl electrolytes was studied through potentiodynamic polarization, optical microscopy and open circuit potential measurement techniques. Results showed SiC additions significantly and progressively decreased the corrosion rate of Mg–Al alloy in both electrolytes due to decrease in the exposed area for the formation of porous Mg(OH)2 on the alloy surface. At 0% SiC wt content the corrosion rate values are 4.930 mm y−1 and 0.259 mm y−1 while at 10% SiC wt content the corresponding values have decreased to 0.429 mm y−1 and 0.090 mm y−1. Anodic potential displacement occurred in H2SO4 at all SiC% wt contents leading to rapid destruction of the protective oxide and absence of passivation characteristics. Mg–Al alloy demonstrated sufficient passivation after anodic polarization in NaCl solution due to the localized electrochemical action of chlorides. Morphological representations showed severe general surface deterioration on Mg–Al specimens from H2SO4 and visible localized deterioration on specimens from NaCl in the absence of SiC. The extent of deterioration on the morphology of Mg–Al alloy decreased at 2.5% and 10% SiC wt Without applied potentials Mg–Al alloy in H2SO4 with SiC was relatively more electropositive due to stability of its protective oxide compare to specimens with SiC. In NaCl solution, the reactivity of chlorides hindered the formation of the protective oxide resulting in more electronegative potential plots. However, the plots of Mg–Al at 2.5% and 10% SiC wt content where thermodynamically unstable due to visible potential transients.

Microstructural, mechanical and corrosion behaviour of Al–Si alloy reinforced with SiC metal matrix composite

The aim of the present study is to investigate the effect of Si and SiC addition on the microstructure, mechanical, and corrosion properties of Al matrix-based composites. Al–Si (2 wt% fixed) alloy reinforced SiC composites were prepared by stir-casting process using SiC reinforcement contents from 0 to 20 wt% at an interval of 5%. A uniform dispersion of SiC particles in the Al matrix was observed from the scanning electron microscopic analysis. Maximum hardness is found for composites having 15 wt% reinforcement content. Pin-on-disc wear test reveals that SiC particles increase the wear resistance of composites. Corrosion test reveals that composites reinforced with 20% reinforcement content shows the minimum i corr among all the compositions, attributing to the maximum corrosion resistance. Tribological and corrosion behaviour were found to be dependent on the reinforcement content. However, they were not interdependent on each other. It is expected that the present study would be helpful in the development of lightweight composites for aerospace and shipping industries applications.

Improvement of erosion resistance of alumina-phosphate ceramic coating on mild steel by SiC addition

This research is focused on the application of the Al2O3-phosphate ceramic coating on mild steel surface to protect mild steel from erosion in coal dust environment. Erosion resistance of mild steel could be improved by overlay it with SiC in the Al2O3-phosphate ceramic coating. As a filler, Al2O3 was mixed with 20%, 40%, and 60% SiC by using aluminium phosphate as a binder and heated at 220 °C for 5 hours. X-ray diffraction testing was conducted to observe the phase of Al2O3-SiC phosphate ceramic coating. Meanwhile, surface morphology and adhesion characteristic of Al2O3-SiC phosphate ceramic coating were analyzed by scanning electron microscope. To analyze the erosion resistance quantitatively solid particle impingement test by applying gas jets at the right angle (90°) against a sample surface has been conducted. The results showed that Al2O3-SiC phosphate ceramic coating is strongly bound to the mild steel surface without the presence of any void. The higher the SiC content can increase the ceramic coating density and its erosion resistance. The SiC 60% produces four times higher erosion resistance than uncoated mild steel. The material characterization of Al2O3-SiC phosphate ceramic coating proves that SiC gives a significant impact on the enhancement of erosion resistance of the Al2O3-SiC phosphate ceramic coating.

Synergic effect of MWCNTs and SiC addition on microstructure and mechanical properties of closed-cell Al–SiC-MWCNTs HCFs

AlSi12Cu1Mg1–SiC-MWCNTs hybrid composite foam (HCFs) of varying relative densities (R.D.) were made through stir casting technique using CaH2 as a foaming agent. Varying wt.% of SiC and multi-wall carbon nanotubes (MWCNTs) were used as reinforcing as well as thickening agents. Uniform distribution of SiC and MWCNTs in the matrix was confirmed by FESEM images and Raman analysis. It was observed that the elastic modulus (E), plastic collapse stress (σpc), plateau stress (σpl), and energy absorption (Eab) of HCFs increase significantly when both (MWCNTs and SiC) were added together. But, when SiC and MWCNTs added individually, the extent of improvement in these properties is relatively low. However, densification strain varies marginally with the variation in reinforcement. Irrespective of reinforcement, the σpl, the E, and the Eab increased with increment in R.D. The different values also followed the existing relations, when the fraction of cell edge materials varied with R.D., the deformation mechanism was understood from photographs taken during deformation.

Analysis of thermo-physical properties of materials suitable for thermal stabilization of superconducting tapes for high-voltage superconducting fault current limiters

High-temperature superconducting coated conductors (CC) are attractive materials for high-voltage resistive fault current limiters. Commercially produced CC tapes cannot withstand electric fields over 100 V m−1, and therefore, they have to be modified by addition of thermal stabilization layer. We investigated several composite systems suitable for such thermal stabilization. As a matrix of composites, Stycast resins were used, which contain various contents of powder particles from SiC, SiO2, PbTiO3, ZrW2O8, or synthetic diamond. The thermo-physical properties such as thermal expansion, heat capacity, thermal diffusivity and direct-current electrical conductivity were measured because they are influenced by filler content in the composite. The possible highest amount of the powder can slightly increase the thermal conductivity and decrease the thermal expansion of the system to an acceptable value needed for the coating of CCs. A side effect is simultaneous drop of heat capacity; however, its value stays still high enough for the purpose of heat sinking. Overall, the best results were achieved in system with 20 vol% of SiC filler in Stycast 2850FT + Catalyst 23LV resin matrix. There the contribution of the semiconducting SiC addition to the electrical conductivity of composite was negligible.

Densification, microstructure, and mechanical properties of ZrC–SiC ceramics

AbstractZrC–SiC ceramics were fabricated by high‐energy ball milling and reactive hot pressing of ZrH2, carbon black, and varying amounts of SiC. The ceramics were composed of nominally pure ZrC containing 0 to 30 vol% SiC particles. The relative density increased as SiC content increased, from 96.8% for nominally pure ZrC to 99.3% for ZrC‐30 vol% SiC. As SiC content increased from 0 to 30 vol%, Young's modulus increased from 404 ± 11 to 420 ± 9 GPa and Vickers hardness increased from 18.5 ± 0.7 to 23.0 ± 0.5 GPa due to a combination of the higher relative density of ceramics with higher SiC content and the higher Young's modulus and hardness of SiC compared to ZrC. Flexure strength was 308 ± 11 MPa for pure ZrC, but increased to 576 ± 49 MPa for a SiC content of 30 vol%. Fracture toughness was 2.3 ± 0.2 MPa·m1/2 for pure ZrC and increased to about 3.0 ± 0.1 MPa·m1/2 for compositions containing SiC additions. The combination of high‐energy ball milling and reactive hot pressing was able to produce ZrC–SiC ceramics with sub‐micron grain sizes and high relative densities with higher strengths than previously reported for similar materials.

Grain refinements of magnesium alloys inoculated by additions of external SiC particles

A homogeneous microstructure of as-cast magnesium alloys is desired to improve the formability during their subsequent thermomechanical processing. Owing to its similar crystal structure to Mg, the part of Zr formed by peritectic reaction during solidification was considered to be the most effective nucleants for alpha-Mg. However, regarding the Al-containing magnesium alloys, up to now no suitable and effective external nucleants were found for them. Recently, it was demonstrated that the additions of SiC worked in refining both the Mg-Al and Mg-Zn alloys. The SiC particles acted as nucleants in magnesium alloys are attracting more attentions. The present work investigated and compared the effects of external SiC particle additions on the grain refinements of Mg-Al and Al-free Mg-Zn (Mn) alloys. Their microstructures were characterized using XRD, SEM and TEM. It was found that the additions of SiC particles could refine the grains of both Mg-Al and Mg-Zn alloys. The SiC particles cannot act as a direct heterogeneous nucleant for the nucleation of alpha-Mg in both Mg-Al and Mg-Zn (Mn) alloys. The responsible mechanisms for their grain refinements are different. Regarding for Mg-Al alloys, the grain refinement caused by the addition of SiC particles is attributed to the formation of a ternary intermetallics Al2MgC2, which has a very similar crystal structure to that of Mg. As for Mg-Zn (Mn) alloys, the grain refinement is attributed to the formation of a (Mn, Si)-enriched intermetallics by the interactions between SiC and impurity Mn in alloys.

Strengthening of Al-4.5%Cu alloy with the addition of Silicon Carbide and Bamboo Leaf Ash

PurposeThe purpose of this paper is to determine the use of BLA along with SiC as economical reinforcements to enhance the mechanical behavior of hybrid composite. The purpose of this research is the development of cost-effective aluminum hybrid metal matrix composites.Design/methodology/approachThe present research work investigation evaluated the mechanical properties of Al-4.5%Cu alloy, Al-4.5Cu/10SiC, Al-4.5Cu/10SiC/2BLA and Al-4.5Cu/10SiC/4BLA composites by the Stir casting method. The fabricated composites were analyzed using optical microscopy (OM), scanning electron microscopy (SEM), and hardness and tensile test.FindingsThe microstructure modification with the addition of reinforcement particles in the matrix alloy and clear interface in between matrix and particles are observed. The density of the composite increased with the addition of SiC and decreased with the addition of BLA in comparison with that of matrix alloy. The hardness and tensile strength of the single-reinforced composite and hybrid composites improved with the addition of reinforcement particles. The strengthening of composites was due to load-bearing capacity of reinforcement particles over the matrix alloy and increased dislocation density of composites materials. The tensile failure mechanism of the composites is reveled with SEM analysis.Practical implicationsThe papers reports the development of cost-effective and light weight aluminum hybrid composites with remarkable enhancement in the mechanical and tribological properties with the addition of BLA as economical reinforcement along with SiC.Originality/valueThe density, hardness and tensile values of fabricated aluminium composites were presented in this paper for the use in the engineering applications where the weight and cost are consider as a primary factors.

Microstructure And Mechanical Properties Of Synthesized Aluminium Composite Using Stir Casting Process

Aluminium is one of the most common metals in the world and its use is increasing day by day in many industries mostly in space industry and automobile industry because of its light weight and high strength capabilities. Aluminium-based alloys have great potential for cost saving application due to their light weight combine with high specific strength and corrosion resistance, as well as good castability. This paper mainly emphasis with the fabrication of Aluminium composites with SiC particles and jute ash particles. Hardness and tensile properties of the prepared Aluminium composite were determined before and after addition of SiC and Jute Ash particulates to find the extent in improvement of properties. SEM images have shown the grain boundaries formation. Results shows that the tensile strength is maximum in case of composite with SiC with value of 123MPA when compared to unreinforced 6061Al matrix with strength of 64MPa.

Effects of SiC and SiC-GNP additions on the mechanical properties and oxidation behavior of NbB2

ABSTRACTMonolithic NbB2, NbB2-SiC, and NbB2-SiC-GNP samples were produced by spark plasma sintering (SPS), and the effects of additives on the mechanical and thermal properties, microstructures, and oxidation behavior of the samples were investigated. The addition of SiC up to 30 vol% decreased the Vickers hardness of the binary composites due to microcrack formation. The fracture toughness and oxidation resistance of NbB2 were improved with the incorporation of SiC. Fracture toughness was higher for all the composites in comparison to monolithic NbB2, moreover the highest value of ~5.2 MPa·m1/2 exhibited by 3 vol% GNP-containing composite. A strong interface and homogeneous distribution of GNPs enhanced the thermal transfer properties and improved the oxidation resistance of selected NbB2-SiC ceramics in oxidation studies at 1200°C. A combination of high mechanical properties, high thermal conductivity, and low mass gain was achieved for the NbB2-SiC-GNP samples with 1 and 3 vol% GNPs.