SiC Addition Research Articles

Microstructure and oxidation resistance of ZrB2–ZrC–SiC composite nanofibers fabricated via electrospinning combined with carbothermal reduction

In this work, ZrB2–ZrC–SiC composite nanofibers were prepared by electrospinning combined with the carbothermal reduction method. The morphology, phase composition, and oxidation resistance of the composite nanofibers were investigated. The results showed that ZrB2–ZrC–SiC composite nanofibers with good crystallinity were obtained after calcination at 1550 °C. The obtained fibers distributed uniformly, and the average diameter was about 375 nm. ZrB2–ZrC–SiC nanofibers were oxidized at 587 °C, which was higher than that of the ZrB2–ZrC nanofibers. It revealed that the addition of SiC could improve the oxidation resistance of ZrB2–ZrC composite nanofibers.

Improvement in Hardness and Wear Behaviour of Iron-Based Mn-Cu-Sn Matrix for Sintered Diamond Tools by Dispersion Strengthening.

The work presents the possibility of fabricating materials for use as a matrix in sintered metallic-diamond tools with increased mechanical properties and abrasion wear resistance. In this study, the effect of micro-sized SiC, Al2O3, and ZrO2 additives on the wear behaviour of dispersion-strengthened metal-matrix composites was investigated. The development of metal-matrix composites (based on Fe–Mn–Cu–Sn–C) reinforced with micro-sized particles is a new approach to the substitution of critical raw materials commonly used for the matrix in sintered diamond-impregnated tools used for the machining of abrasive stone and concrete. The composites were prepared using spark plasma sintering (SPS). Apparent density, microstructural features, phase composition, Young’s modulus, hardness, and abrasion wear resistance were determined. An increase in the hardness and wear resistance of the dispersion-strengthened composites as compared to the base material (Fe–Mn–Cu–Sn–C) and the commercial alloy Co-20% WC provides metallic-diamond tools with high-performance properties.

Additively manufactured SiC-reinforced stainless steel with excellent strength and wear resistance

Abstract Additive manufacturing enables in-situ alloying of multi-component materials for the development of novel and high-performance materials. Here laser powder bed fusion (LPBF) of SiC-reinforced 316L stainless steels metallic matrix composites (MMCs) for improved strength and wear resistance were investigated. The densification behaviour, microstructural evolution, crystallographic orientation and properties of the LPBF-processed MMCs with different SiC contents were systematically investigated. The formation mechanisms of pores and cracks are discussed. Microstructural observations reveal that the microstructure changes from equiaxed to dendritic with increasing SiC are related to the different temperature gradient and solidification rates. The SiC addition affects crystallographic orientation and causes grain refinement to 316L. In addition, micron SiC particles are refined to nano-scale after laser processing, which induces massive dislocations in the 316L matrix. The strength and tribological properties of 316L are significantly improved by SiC addition, in which the 9 vol% SiC reinforced MMC reaches a high tensile strength of about 1.3 GPa, together with a low wear rate of 0.77 × 10−5 mm3/Nm. The achieved strength and wear resistance are at the highest level among literature, and the underlying strengthening mechanisms are elucidated.

Enhanced mechanical properties of 6082 aluminum alloy via SiC addition combined with squeeze casting

In order to improve mechanical properties of 6082 aluminum alloy, the SiCp/Al 6082 composites were prepared by the addition of the micron-sized SiC particles combined with the squeeze casting. The effects of the SiCp content and squeeze casting on the microstructure and mechanical properties of the 6082 aluminum alloy were investigated by SEM, EDS, TEM, tensile testing and hardness testing analysis methods. Research results exhibited that the SiCp content and squeeze casting had a significant impact on the microstructure and mechanical properties of the 6082 aluminum alloy. The addition of the SiCp refined the grain size of the 6082 aluminum alloy while caused the increase of the porosity with increasing the SiCp content, especially in the permanent mold casting condition. Compared to the permanent mold casting, the squeeze casting obviously reduced pore defects, refined grain size and made the SiCp distribute evenly as well as bond tightly with the Al matrix. The tensile strength, yield strength, elongation, elastic modulus and hardness of the 6082 aluminum alloy obtained with the SiCp and squeeze casting were remarkably improved, and the optimal mechanical properties were obtained with a 2 wt.% SiCp, and they increased 10.73 %, 72.7 %, 193.9 %, 23.5 % and 25.2 %, respectively, compared to those of the 6082 aluminum alloy obtained without SiCp and squeeze casting. The fracture surface of the SiCp/Al 6082 composites obtained with the squeeze casting was dense and exhibited a ductile fracture mode.

Self-propagating high temperature synthesis (SHS) of porous Si3N4-based ceramics with considerable dimensions and study on mechanical properties and oxidation behavior

The aim of present work is to fabricate porous Si3N4 ceramics with considerable dimensions and homogeneous microstructure by self-propagating high temperature synthesis (SHS) using Si, Si3N4 diluent and Y2O3 as raw materials. The results indicate that Si3N4 diluent with coarse particle sizes and appropriate β-phase content is beneficial to obtain porous Si3N4 ceramics with homogeneous microstructure and excellent mechanical property by controlling the shrinkage inside the sample. The produced Si3N4 ceramics possessed excellent flexural strength of 168 MPa∼259 MPa, and high Weibull modulus of 11.0∼17.2. Additionally, BN and SiC are added as second phase to modify the properties of Si3N4-based ceramics. Optimum flexural strength of 170 MPa and 137 MPa were obtained with 10 wt.% addition of BN and SiC respectively. After oxidation at 1100 °C∼1300 °C, second phase-doped Si3N4 ceramics also presented higher residual strength than pure Si3N4 ceramics.

Glass/Caryota urens hybridized fibre-reinforced nanoclay/SiC toughened epoxy hybrid composite: mechanical, drop load impact, hydrophobicity and fatigue behaviour

Glass/Caryota urens hybridized fibre-reinforced nanoclay/SiC toughened epoxy hybrid composites were prepared and characterized for its mechanical, drop load impact toughness, hydrophobicity, and fatigue behaviour. The rapidly increasing demand in polymer matrix composites proportionally increasing the environmental pollution and now this factor is a prime concern for all researchers worldwide. Thus, this research study is aimed to prepare and investigate the natural fibre-based polymer matrix composites by keeping the environmental factors in consideration. Replacing the synthetic fibres completely by natural fibre also not a great development since, the natural fibres are inferior in useful properties. Thus, in this present investigation, a hybrid form of glass-Caryota urens fibre was introduce as primary reinforcement for nanoclay-SiC toughened epoxy resin matrix. The mechanical and drop load impact results revealed that the addition of nanoclay and SiC into the epoxy resin improved the toughness together with glass-Caryota urens hybrid fibre. Moreover the addition of nanoclay and Caryota urens fibre in epoxy resin matrix improved the fatigue life cycle up to 55,182 for 50% of ultimate tensile stress. The hydrophobicity of silane-treated reinforcements gives marginal loss in water absorption compared to bare epoxy resin. These properties improved hybrid fibre epoxy composites could be used in many engineering applications.

Interfacial microstructure evolution and properties of Sn-0.3Ag-0.7Cu–xSiC solder joints

Abstract The impacts of SiC on the wettability, mechanical properties and growth of intermetallic compound (IMC) of the low silver Sn-0.3Ag-0.7Cu (SAC0307) –xSiC composite solders paste prepared by mechanical mixing were investigated. It is found that there is an improvement in the wettability and a large reduction in the thickness of IMC with increasing SiC content, such as the contact angle shrinks by 11.48% and the thickness of IMC at the interface decreases by 63% with 0.10 wt% SiC addition. Meanwhile, according to the fracture morphology analysis, the IMC grains are refined repeatedly with increasing SiC content before less than 0.06 wt%, then agglomerated SiC and brittle phase Ag3Sn appear with further increase in SiC content. As a result, the tensile strength of solders joint increased continuously up to the maximum value of 30.49 MPa with 0.06 wt% SiC addition.

Effects of particulate reinforcements on the hardness, impact and tensile strengths of AA 6061-T6 friction stir weldments

Due to loss of structural strengthening at temperatures beyond 250°C, heat-treated aluminium alloys (e.g. AA 6061-T6) weldments are usually characterized with poor mechanical properties including hardness, tensile and impact strengths. In this work, friction stir weldments of AA 6061-T6 reinforced with the additions of SiC, B4C and Al2O3 particles at the joints were produced and investigated for improved hardness, tensile strength and impact strength over the unreinforced weldment. The results showed that the entire reinforced welded joint exhibited improved hardness because of the enhanced metal matrix grain refinement and inherent high hardness of the reinforcement particles. B4C particle addition produced hardest joint of about 81% of the base metal hardness (∼114 HV0.3). The impact energies of the SiC (16.9 J), B4C (16.5) and Al2O3 (12.2 J) reinforced weldments are closer to that of the base metal (18.6 J) compared with the unreinforced weldment (9.6 J). The reinforced weldments showed no significant improvement over the tensile strength of the unreinforced weldment. B4C and SiC reinforcements produced the highest improvements in the hardness (at the joint) and impact strength of the AA 6061-T6 friction stir weldments, respectively.

Characterization of reactive spark plasma sintered (Zr,Ti)B2–ZrC–SiC composites

This investigation aims to evaluate the influence of SiC introduction on the microstructure development, mechanical characteristics, and densification behavior of (Zr,Ti)B2–ZrC materials. Two specimens, with/without SiC addition, were manufactured from the starting materials of ZrB2 and TiC by reactive spark plasma sintering (SPS) at 1800 °C under 30 MPa for 5 min. Both samples reached relative density values higher than 99%; however, the SiC addition improved this value by ~0.5%, standing at 99.9%. The SiC incorporation into the (Zr,Ti)B2–ZrC system led to an ultrahigh temperature ceramic (UHTC) with considerable hardness and elastic modulus. The TiC additive was completely consumed over the sintering process, participating in the in-situ formation of TiB2 and ZrC as a result of a chemical reaction with the ZrB2 matrix. Thanks to the diffusion of Ti and Zr atoms into the ZrB2 and TiB2 phases, respectively, a solid-solution of (Zr,Ti)B2 formed with various compositions in different areas. Thanks to the synergistic effects of grain refinement and solid-solution formation, the (Zr,Ti)B2–ZrC–SiC sample reached excellent mechanical properties such as an elastic modulus of 495 GPa and a hardness of 31.2 GPa.

An Experimental Study on Mechanical Properties of SiC and Short Basalt Fiber Reinforced Aluminium Alloy LM 25Composite

The current investigation manages the conduct of aluminum LM25 sic composites and strengthened with basalt fiber. The first one of the composites consists of LM25 without adding any material. The second one of the composite has LM25 with 1% Basalt fiber and 1% SIC activated SIC powder state. Third one of the composite 2% basalt fiber and 2%SIC, fourth composite consists of 3%of basalt fiber and 3% of SIC, and all the composites are fabricated through ‘Stir Casting Method’. Mechanical properties like Tensile strength and effect qualities were tried essentially. The tried examples were inspected utilizing Scanning Electron magnifying instrument to separate support material and network material on the outside of composite. The Main Aim is to be results of the aluminium alloy LM25 metal are compared with aluminium alloy LM25, basalt fiber and sic based metal framework composites at relating estimations of test boundaries. The expansion of short basalt fiber and sic improves the yield quality and extreme elasticity of aluminum composite LM25 contrast with the unreinforced grid. A definitive rigidity, impact test, and microstructures of Al LM25, Ductility of composite increases with the addition of short basalt fiber and sic.

Influence of Hot Extrusion on the Microstructure, Tensile and Wear Properties of Mg–5Sb–xSiC Hybrid Composites

The structure, hardness, tensile and wear behavior of Mg–5Sb–xSiC hybrid composites experimented where the amount of SiC particles were 1, 3, and 5 wt% SiCp before and after applying hot extrusion process. Micron size SiC particles were added to Mg–5Sb alloy via stir casting technique to form both Mg3Sb2 and SiC particles in the as-cast microstructures. Although SiC addition reduced the grain size of the Mg–5%Sb in-situ metal matrix composite (MMC), no improvement was observed on ultimate tensile strength (UTS) and the ductility (EL.%) in the as-cast state. The use of the extrusion process led to a remarkable fracturing of Mg3Sb2 intermetallic along the extrusion direction, grain refinement, and reduction in the size of SiC clusters. The optimal amount of SiC was found to be 3 wt%, which reduced the grain size from ~ 827 to ~ 4 µm and promoted the UTS amounts from 120 to 244 MPa for as-cast and hot extruded composites. Besides, the enhancement of yield strength of extruded MMCs was rationalized depending on the grain size compared to the as-cast condition. The fractography of the as-cast composites revealed more cleavage planes in contrast with hot extruded composites, which proved much more dimples. It was also found that the use of hard SiC particles in hybrid composite improved wear properties just in the extruded state. According to observations, in various sliding test conditions, the abrasive, oxidation and delamination are mostly operated in combination.

3D characterization of the SiC nanoparticle distribution in ZrB2–SiC ceramics with synchrotron X-ray nanoscale computed tomography

Evaluating the dispersion of SiC nanoparticles is significant for the development of ZrB2–SiC nanocomposite ceramics. This paper reports the 3D distribution characterization of the nanosized SiC additives in ZrB2–SiC ceramics with synchrotron X-ray nanoscale computed tomography (nano-CT) and Morisita indexes. Different from the investigation with electron microscopy, the presented work implements nondestructively 3D visualization and quantitative characterization of the SiC nanoparticles distribution in ZrB2–SiC ceramics. Firstly, a ZrB2–SiC ceramic sample with a size less than 60 μm was prepared. Then, a nano-CT experiment was designed and implemented for this sample at the 4W1A beamline of Beijing Synchrotron Radiation Facility (BSRF). Next, SiC nanoparticles were extracted by applying image segmentation to the generated 3D nano-CT images of this sample and visualized by volume rendering. Finally, Morisita index was extended from 2D to 3D and applied to the corresponding nano-CT images for the quantitative characterization of SiC nanoparticle 3D distribution. The results from the Morisita index are in good agreement with the visual observation. They reveal that SiC agglomerates exist in the ZrB2 matrix and vary over the regions of interest in the investigated sample.

Effects of SiC on microstructure and properties of plasma sprayed ZrB2–ZrC composite coating

The effects of SiC on microstructure and properties of plasma sprayed ZrB2–ZrC composite coating were investigated. Plasma sprayed ZrB2–ZrC and ZrB2–ZrC–SiC composite coatings were prepared and compared. The addition of SiC could improve the density of the ZrB2–ZrC–SiC coating that lead to better mechanical properties. The reason was that SiC improved the melting state of powder feedstocks during plasma spraying process and refined grains in ZrB2–ZrC–SiC composite coating.

The effect of nanometer phase SiC addition on the microstructure and mechanical properties of Al0.6CrFe2Ni2 high entropy alloys

ABSTRACT To improve the strength of single FCC phase Al0.6CrFe2Ni2 high entropy alloy without reducing the plasticity, nano-phase SiC was selected as reinforcement phase. Aseries of as-cast SiC/Al0.6CrFe2Ni2 high entropy alloys with different SiC content (0, 1.25, 2.5, 3.75, 5 vol%) were prepared by vacuum arc melting furnace. And the effect of SiC addition on the microstructures and mechanical properties of Al0.6CrFe2Ni2 high entropy alloy was analysed by microstructure observation, element distribution analysis, compression tests and hardness tests. The results show that the Cr7C3 particles were found in the grain boundaries due to the decomposition of SiC in high temperature, the size and quantity of Cr7C3 particles grow and spread throughout the alloy gradually with the further increase of SiC content. When the added SiC content is 2.5 vol%, the alloy has better comprehensive properties, the yield strength and hardness are 618.43 MPa and 250.78 HV, respectively.

EVALUACIÓN DEL COMPORTAMIENTO MECÁNICO DE BARRERAS TÉRMICAS MEDIANTE TÉCNICAS DE EMISIÓN ACÚSTICA

To develop more efficient turbines, it is necessary to increase the inlet temperature and / or decrease the temperature losses for these reasons it is necessary to develop materials resistant to higher temperatures and with lower heat transfer coefficients. A technological solution to this problem is the implementation and subsequent improvements of thermal barriers coating (TBC). In general, these TBCs are composed of a ceramic coating and an intermetallic layer that serves as a bond coat between the ceramic and the substrate to be protected. The Y2O3 stabilized ZrO2 (Y-TZP), is one of the ceramics used as TBC. However, the thermomechanical fatigue to which these barriers are subjected causes them to deteriorate, forming cracks and / or delaminations. One way to counteract this effect is the addition of an agent that allows self-healing, that is, as a crack in the barrier occurs, at the same time, the recovery of this defect is generated as a result of temperature, diffusion and / or self-healing reaction. The aim of this work is the study by acoustic emission AE of the mechanical behavior of the TBCs with the addition of SiC in the suspension of Y-TZP / Al2O3. In the same way, a microstructural analysis and a finite elements model was carried out in order to compare results. The coatings were made by Suspension Plasma Spray (SPS) on metal plates of 70x10x2 mm, an intermetallic was deposited as a bond coating and finally a coating of Y-TZP / Al2O3 with and without 15% wt SiC. The AE becomes a fundamental tool in the study of the mechanical behavior of thermal barriers. The use of wavelet transforms streamlines the study and analysis of recorded sound spectra. The cracks generation arises at very low stress levels.

Influence of SiC Addition on Mechanical Behavior of Thermal Barriers with the Aid of Acoustic Emission

The improvement of high temperature materials with lower heat transfer coefficients lead to the development of thermal barrier coatings (TBCs). One of the most widely used materials for thermal barrier coatings is Y2O3 stabilized ZrO2 (Y-TZP) because of its excellent shock resistance, low thermal conductivity, and relatively high coefficient of thermal expansion. The aim of this work is to study the TBCs mechanical behavior with the addition of SiC into the suspension of Y-TZP/Al2O3 by acoustic emission (AE). Additionally, a microstructural analysis and a finite elements model were carried out in order to compare results. The coatings were made by suspension plasma spray (SPS) on metal plates of 70 × 12 × 2 mm3. An intermetallic was deposited as a bond coating, followed by a coating of Y-TZP/Al2O3 with and without 15 wt.% SiC, with thicknesses between 87 and 161 μm. The AE becomes a fundamental tool in the study of the mechanical behavior of thermal barriers. The use of wavelet transforms streamlines the study and analysis of recorded sound spectra. The crack generation arises at very low stress levels.

Optimization of SiC Abrasive Parameters on Machining of Ti-6Al-4V Alloy in AJM Using Taguchi-Grey Relational Method

In this research, multi response Taguchi-grey relational approach was employed to optimize the machining parameters of Ti-6Al-4V alloy in abrasive water jet process. The main aim of this present investigation was to explicate the role of adding SiC super hard ceramic into the garnet and to find out the optimal input variable, which is influencing the material removal rate and surface finish in the process. The specific input variables such as SiC volume, SiC size and abrasive flow rate were accounted as potential process variables for this present investigation. It is observed that the SiC along with garnet improves the material removal rate. According to the analysis the SiC addition of 0.5 wt.%, SiC size of 80mesh and abrasive flow rate of 2 g/s (A2B1C1) was found to be producing MRR of 48.81 mm3/s and lower surface roughness of 3.72 μm. From study the particle size was the most influential parameter for producing high MRR with low surface roughness. The confirmation study reveals the improvement of 1.91% in MRR and surface roughness on comparing with predicted mean value.

A Re-investigation: Effect of various parameter on mechanical properties of copper matrix composite fabricated by powder metallurgy

In this study, a re-investigation on metal matrix composite fabricated by powder metallurgy route has been done. Copper based metal matrix composite has the wide applications because of their good electrical, thermal and mechanical properties. Copper has good strength and resistance to corrosion. But in order to increase the properties of copper, copper matrix composite has been fabricated by powder metallurgy process. The composites materials fabricate by powder metallurgy process has various property such as hardness, tensile strength, compressive strength, toughness, fatigue strength. These properties depend on some parameter such as reinforcement, pressure during powder compaction, temperature of sintering, holding time at sintering temperature, particle size, volume fraction of reinforcement etc. This study shows investigation of effect of various parameter on mechanical property of copper-based metal matrix composites. It has shown that due to presence of secondary phase hard particle like alumina, SiC, titanium carbide, TiO2 in copper metal matrix increase hardness, strength and reduce density. Reduction in density is very important in order to fabrication of automobile and aircraft parts. The strength and hardness increase with addition of SiC but ductility is reduced. It is shown that sintering temperature and sintering time is most important parameter because it highly influences hardness and strength.

Analysing the Microstructures and Pin-on-Disc Wear Properties of 1010 Steel-Based and B<sub>4</sub>C-Added Materials Produced through Powder Metallurgy

The present study makes use of two distinct production methods. The first method involves producing 1010 steel-based materials containing SiC, MgO, H3BO3, and B4C (wt%10 - wt%30) with varying weights through powder metallurgy. This step was followed by hot pressing. In the second group, after all the chemicals were stirred, 20 ml of epoxy and epoxy hardener were added to the mixture. Then, the mixture was set aside to harden. XRD and SEM-EDS analyses were conducted on the mixture to observe the morphological impacts. Furthermore, friction coefficient values of the materials were also identified following wear tests under varying weights. The XRD analyses revealed the phase structures of Fe3C, SiC, MgO, H3BO3, B4C, and Fe2O3. As for the SEM-EDS analyses, they concluded the surface appearance of S60 and S55B20, the hot-pressed materials, dependent on liquid phase sintering. SEM of epoxy- based S60E20 and S55B20E20 revealed white spherical structures and a flat matrix structure with shallow surface holes. In the pin-on-disc wear experiment, the friction coefficient value was reduced with the addition of SiC, MgO, and H3BO3 (S60) to 1010 steel (S100). By adding various amounts of B4C, the friction coefficient was reduced even further, resulting in the improvement of wear properties.

Investigation of mechanical characteristics of materials based on refractory borides

The object of research is the effect of sintering under pressure (10 MPa–4.1 GPa) on the formation of the structure and properties of ZrB 2 , HfB 2 , and composites on their bases. It has been found that high pressure consolidation results in an improvement of mechanical characteristics. In particular, the hardness and fracture toughness of the materials sintered under 4.1 GPa pressure are higher than those of the materials obtained under hot pressing conditions at 20–30 MPa and spark-plasma sintering at 50 MPa. High-pressure sintered HfB 2 demonstrated hardness H V (9.8 N)=21.3±0.8 GPa, H V (49 N)=19.3±1.3 GPa, and H V (98 N)=19.2±0.5 GPa and fracture toughness K 1C (49 N)=7.2 MPa · m 0.5 and K 1C (98 N)=5.7 MPa · m 0.5 . The HfB 2 sintered by hot pressing at 1850 °C and 30 MPa demonstrated hardness: H V (9.8 N)= 19.0 GPa , H V (49 N)= 18.7 GPa, and H V (98 N)=18.1 GPa, K 1C (9.8 N)=7.7 MPa · m 0.5 , K 1C (49 N)=6.6 MPa · m 0.5 and K 1C (98 N)=5.3 MPa · m 0.5 . High pressure sintered ZrB 2 (a=0.3167 nm, c=0.3528 nm, γ=6.2 g/cm 3 ) demonstrated H V (9.8 N)=17.7±0.6 GPa, H V (49 N)=15.4±1.2 GPa, and H V (98 N)=15.3±0.36 GPa and K 1C (9.8 N)=4.3 MPa · m 0.5 , K 1C (49 N)=4.2 MPa · m 0.5 and K 1C (98 N)=4.0 MPa · m 0.5 . Addition of 20 wt. % of SiC to ZrB 2 and sintering under high pressure (4.1 GPa) allowed essential increase of hardness to H V (9.8 N)=24.2±0.7 GPa, H V (49 N)=16.7±0.5 GPa, and H V (98 N)=17.6±0.4 GPa and fracture toughness to K 1C (49 N)=7.1 MPa · m 0.5 , K 1C (98 N)=6.2 MPa·m 0.5 ; the material density was γ=5.03 g/cm 3 . Additions of SiC and Si 3 N 4 to ZrB 2 lead to some increase in fracture toughness (up to K 1C (98 N)=9.2 MPa · m 0.5 ). The developed ZrB 2 - and HfB 2 -based materials and composites can be used for aerospace applications, in cutting and refractory industries, etc.