SiC Addition Research Articles

Effect of SiC addition on the microstructure and properties of Ti6Al4V by selective laser melting

The fine crystalline behavior of SiC/Ti6Al4V is revealed in this study. Titanium matrix composites (TMCs) with different types, amounts, and morphologies of second phases were prepared in situ by adding different contents of SiC. The grain refinement mechanism of multi-phase synergistic was analyzed, and the synergistic contribution of the in-situ second phases (TiC, Ti5Si3, and Ti3Si) as well as the fine grain organization to the strengthening of the materials was quantitatively evaluated. The results show that the quasi-continuous network structure formed by the in situ TiC and Ti5Si3 phases inhibits grain growth and completes the equiaxed transformation of β-grains. Meanwhile, the TiC phase provides a large number of nucleation sites for the α-Ti phase, which promotes the nucleation of the matrix phase. Finally, the aspect ratio of the α phase was reduced from 5.8 to 3.1, while the β grain size was refined from 20.0 to 1.7 µm. The matrix hardness (6.3 GPa) and compressive yield strength (1692 MPa) of TMC were increased by 37 % and 67.4 % respectively compared with Ti6Al4V. Fine grain strengthening accounted for 71.2 % of the total strengthening increase. The load-bearing strengthening caused by TiC, Ti5Si3 and Ti3Si accounted for 6.0 %, 11.6 % and 3.0 % of the total strengthening increase, respectively.

SiC addition to a dual phase high entropy ultra-high temperature ceramic

SiC addition to a dual phase high entropy ultra-high temperature ceramic

Processing and characterization of Ultra High Temperature High‐Entropy (Ti0.2Zr0.2Hf0.2Mo0.2W0.2)B2-based Ceramics: Effect of W granulometry, graphite, and SiC addition

A highly dense and single phase (Ti0.2Zr0.2Hf0.2Mo0.2W0.2)B2 ceramic product is obtained in this work at 1950°C (20 min, 20 MPa) by Spark Plasma Sintering (SPS) from powders prepared by Self-propagating High-temperature Synthesis (SHS). The formation of the (W,Mo)B2 secondary phase is avoided using fine W precursors and adding 1 wt% graphite to the SHS powders before SPS. Kinetic limitations responsible for hindering the synthesis of the high entropy boride are correspondingly eliminated. The resulting 98.5 % dense sample exhibits a homogeneous microstructure, with Vickers hardness of 26.8 GPa. The introduction of 20 vol% SiC produces an increase of the KIC values from 2.32 to 5.11 MPa m1/2. Very relevant is that the volatilization of Mo- and W-oxides occurring during sample oxidation at high temperature, which leads to its rapid degradation with the formation of a very porous oxide scale, can be strongly inhibited by the silicate phases generated in the composite ceramic.

Phase formation, microstructure and mechanical properties of TaB2–SiC composites synthesized by reaction hot pressing: Effects of SiC contents and oxygen impurity

TaB2–SiC composites with 0–20 wt% SiC contents were prepared by reaction hot pressing using Ta, B and SiC powders as starting materials. Densification, constituent phases, microstructure and mechanical properties, namely Vickers hardness, fracture toughness and flexure strength, were evaluated by means of inspection of sintering shrinkage, density measurement, XRD, SEM, TEM, HRTEM, EDS, SAED, indentation and three-point bending tests. Phase formation, including dominant (TaB2, SiC) and minor (TaC, glassy SiO2) phases, was checked by thermodynamic assessment relevant with Ta2O5 and B2O3 impurities introduced into the reaction system by the starting powders. The results showed that mixtures of Ta, B and SiC powders would initiate self-propagating combustion synthesis (SPCS) at about 900 °C; a transient hold at 800 °C for 1 h could suppress this reaction. Volatilization of B2O3 impurity in association with local high temperature due to SPCS helped reduce the TaC and glassy SiO2 minor phase formation. TaB2–SiC composites could reach 99 % relative densities with 3 wt% SiC addition and above. Compositions with <7.5 wt% SiC additions showed uniform dispersion of SiC particles at multi-TaB2 grain junctions while compositions with higher SiC content revealed SiC segregation. Bending strength of 503 MPa and fracture toughness of 6.69 MPa⋅m1/2 could be reached with 7.5–20 wt% SiC addition.

Experimental investigation of hybrid reinforced A356 aluminium alloy synthesised by stir casting technique

Abstract One of the most significant alloys to be employed in the automotive, aerospace, and military industries in recent years is A356 aluminium. Because of A356's excellent compatibility with other metals and nanoparticles, novel hybrid composites may be made using it. The characteristics of these hybrid composites are mostly the result of the additives' interaction with the A356 alloy's current elemental composition. Aluminium composites were synthesized through stir casting method by reinforcing 2%, and 4% SiC, 2% and 4 % Al2O3 and 0.5%, 1%, 1.5%, 2% and 2.5% SiC and Al2O3 both. The homogeneous distribution of SiC and Al2O3 microparticles in reinforced composite is revealed by scanning electron microscopy (SEM). The addition of SiC and Al2O3 reinforcements greatly improved the mechanical characteristics of the synthesised composites; for example, a composite with 4% SiC reinforcement reached its maximum hardness and maximum tensile strength of 165 HV and 257MPa respectively. Maximum elongation of 6.72 % was observed for 0.5% SiC and 0.5% Al2O3 reinforced composite. Minimum wear rate is observed for 4% SiC reinforced composite material. This study aims to identify gaps in the potential variations and compatibility of various additives with one another in order to create a brand-new hybrid reinforced alloy suitable for automotive braking system applications: brake rotors made of a disc or a brake pad, depending on the properties of the hybrid reinforced alloy that was made. Hence, the current work presented focuses on the preparation of hybrid reinforcement of A356 with silicon carbide and alumina powders.

Prediction of thermal conductivity in UO2 with SiC additions and related decisive features discovery

Next-generation accident-tolerant fuels for light-water reactors (LWRs) are being developed with high thermal conductivity additives. To reduce the high centerline temperatures that occur in present LWR fuel, complex fuels with improved heat dissipation capabilities are the goal. Depending on the manufacturing process, these fuels can use a variety of additives, and their microstructures vary. The thermal conductivity of UO2-SiC complex fuel is predicted using the finite element method (FEM) and machine learning (ML), as shown in this research. The method accurately predicts the corresponding complex fuel thermal conductivity and captures the characteristic value successfully. Novel anisotropic fuel pellets with higher thermal conductivity in a desired direction can be designed through the application of FEM and ML to material design. Data from published experiments with UO2-SiC complex fuel are used to validate the model and methodology. The model finally predicts the ideal characteristic parameters of the UO2-SiC based on the expected thermal conductivity.

Regulating the metabolites through SiC, ZnO, and SnO2 nano-photocatalysts for elevating efficiency of photo fermentative bioH2 from Arundo donax L.

Photo-fermentation offers a promising roadmap for hydrogen production through their ability to harness light energy, however, its lower conversion efficiency is the major bottleneck for its realization. This study investigates the catalytic role of wideband gap nano-photocatalysts (SiC, ZnO, and SnO2) in enhancing hydrogen generation from Arundo donax L. Physio-optical characteristics of SiC, ZnO, and SnO2 nano-photocatalysts were assessed through SEM, XRD, and FT-IR which confirmed that incorporated nano-photocatalysts are spherical with uniform size distribution and there is no secondary phase. Hydrogen production experiments with varying nano-photocatalyst concentrations revealed that the maximum hydrogen yield of 104 and 98.83 mL/g was achieved with SiC and ZnO, respectively, at loading concentration of 200 mg/L, whereas 69.30 mL/g were observed with 100 mg/L of SnO2. The incorporation of SIC, ZnO, and SnO2 nano-photocatalyst permitted to increase the hydrogen content in overall gas production by 41 %, 37.34 %, and 18.26 % as compared to the control group. The increase in hydrogen production is related to the enhanced e-h pair separation lifetime of SiC, confirmed from PL spectroscopy. Addition of SiC caused a longer availability of electrons that helped to increase the metabolic rate by 38 % and 40.29 % in energy conversion efficiency (ECE). ANOVA results revealed significant differences between the control and maximum values of CHP, HC%, byproducts, and ECE. Tukey pairwise comparisons showed that SiC and ZnO had non-significant differences at 200 mg/L but both significantly outperformed SnO2 at 100 mg/L. Thus, the selection of suitable catalysts photocatalysts with enhanced e-h pair separation lifetime may offer promising prospects for sustainable energy technologies by enhancing biohydrogen production.

Microstructure and mechanical properties of in-situ SiO2-reinforced mechanically alloyed CoCrFeNiMnX (X= 5, 20, 35 at.%) high-entropy alloys

The CoCrFeNiMnX (X = 5, 20, and 35 at.%) alloys, reinforced with 5 at.% SiC powder, were prepared by mechanical alloying and spark plasma sintering. This preparation method resulted in microstructural refinement of the FCC solid solution grains, while the SiC addition reacted with residual oxygen to form homogeneously distributed ultrafine SiO2 particles. Additionally, the alloys contained Cr7C3 carbides, which were significantly larger than the SiO2 particles and enriched with the alloy's elements, including Mn. Among the tested materials, the reinforced CoCrFeNiMn20 alloy exhibited the highest hardness and compressive yield strength (CYS), achieving 392 ± 9 HV30 or 476 ± 3 HVIT1 and 1024 ± 18 MPa, respectively. This alloy also maintained superior CYS (956 ± 35 MPa) even after 100 h of annealing at 800 °C. The reduction in CYS after annealing was smallest for the CoCrFeNiMn5 alloy (35 MPa) and increased with higher Mn content, highlighting Mn's significant role in diffusion-related processes. At elevated temperatures (600 and 800 °C), the CoCrFeNiMn5 alloy had the highest CYS of 190 ± 33 MPa, while the CoCrFeNiMn35 alloy had the lowest at 80 ± 6 MPa. This trend was also observed in wear rate tests, where the CoCrFeNiMn5 alloy had the lowest specific wear rate coefficient of 3.54 ± 0.09 × 10-4 mm³ N⁻1 m⁻1. This was due to matrix softening and oxide lubrication without significant spalling. Thus, the CoCrFeNiMn5 alloy demonstrated superior mechanical properties and wear resistance under various conditions, making it a promising candidate for applications requiring high strength and durability.

Microstructural evolution and high-temperature oxidation behavior of plasma sprayed SiC-YSZ TBCs

In this work, the effect of SiC addition on the microstructure, porosity, phase composition, weight gain, and thickness of TGO of the coatings after repeated oxidation at 1300 °C for various time of APS SiC-YSZ TBCs have been investigated. The phase of the as-sprayed coatings is consisted of t’-ZrO2, SiC and very little SiO2. With the increase of SiC addition, the diffraction peak intensity of SiC and SiO2 are both increased. SiC and SiO2 can fill into the pores in YSZ effectively. However, the porosity in the coatings has little changed with the increased of SiC addition. The addition of SiC during repeated oxidation at 1300 °C can limit the development of the m-ZrO2 phase while causing no ZrO2 lattice deformation. Increasing the SiC addition can impede the growth of TGO between the bonding layer and the ceramic layer, lowering the thermal weight gain rate of the SiC-YSZ coating. The lowest thermal weight gain rate occurs when the SiC composite concentration is 15 wt%. When the composite content of SiC is increased by 10 wt%, the percentage of O element at the interface between the bonding layer and the ceramic layer decreases by approximately 6.56 wt%. Increasing the SiC concentration will improve the compactness of the interface between the bonding and ceramic layers, and limit grain formation in the bonding layer. However, the SiC composite composition must match the ceramic coating's porosity. When the SiC percentage is too low, the ceramic layer's porosity increases and TGO development accelerates. When the SiC concentration is too high, it agglomerates and connects within the coating, causing the coating to fail off during high temperature service.

Enhanced fracture toughness of high entropy boride by adding SiC

The effect of SiC content (10 vol%, 20 vol% and 30 vol%) and sintering temperature (1800 °C, 1900 °C and 2000 °C) on the microstructure and mechanical properties of high entropy boride-silicon carbide (HEB-SiC) composites were systematically investigated in this work. The densification was gradually increased with the increase of SiC content and sintering temperature. More specially, the densification of HEB-30 vol% SiC composite obtained at 2000 °C was as high as 99.1 %. As for the mechanical properties, the dense HEB-30S-2000 composite possessed the highest fracture toughness (5.24 MPa m1/2) and Vickers hardness (28.5 GPa). The above significantly enhanced fracture toughness was closely pertained to the fracture modes adjusting. In details, after the addition of SiC, the branching and bridging of crack, the rupture of large SiC grain, and the deflection of crack existing near the HBE matrix and SiC particles jointly promote the improvement of fracture toughness. Besides, the Vickers hardness increased linearly with the relative density increasing. A simplified equation was established, which could effectually reflect the linear connection between the Vicker hardness and relative density (SiC content) of HEB-SiC composites. It will certainly play an important guiding role in the further development of HEB-SiC composites.

A comprehensive investigation on the effect of SiCp on microstructure and mechanical properties of Mg–5Sb-based hybrid composites

Microstructural development, strengthening mechanisms, and mechanical properties of the newly developed Mg–5Sb-xSiCp (x = 0, 1, 3, and 5) composites were studied in both as-cast and extruded states. The microstructures of composites were composed of α-Mg, in-situ Mg3Sb2, and SiCp phases. The cooling curves display that Mg3Sb2 intermetallics form as the primary phase. During solidification, the SiCp acts as heterogeneous sites for both α-Mg and intermetallics formation. The increase in SiCp content (from 0 % to 5 %) modified the as-cast grain size from 827 μm to 411 μm with the improvement of yield strength (YS) (74–97 MPa). Also, the SiC addition to as-cast facilitates the formation of a randomized texture and a significant reduction in intensity from 13.121 mrd to 6.301 mrd for SiC-Free and 5 wt% added MMCs, respectively. Grain refining and recrystallization are characterized by electron backscatter diffraction (EBSD) analysis. Grain refinement via SiCp and hot extrusion leads to substantial structural refinement, resulting in a decrease in grain size from about 411 μm down to 3.92 μm for MMC with 5 wt% of SiC. Consequently, the best combination of the ultimate tensile strength (UTS) (∼244 MPa) and total elongation (∼8.9 %) was obtained for the hot extruded composite containing 3 wt% SiCp. The prevailing strengthening mechanisms are supposed to be particle strengthening mechanism in the as-cast condition and coefficient of thermal expansion (CTE), Orowan, and Hall-Petch mechanisms in the as-extruded condition. Obviously, adding SiCp and employing hot working lead to significant increase in ultimate compressive strength (from 180 MPa to 321 MPa for 5 wt%).

High-temperature stability of wave absorption properties for SiC enhanced ZrB2–Al2O3 ceramics

To address the challenge of high-temperature microwave absorbing materials (MAM) for the hot-end components of aircraft, SiC enhanced ZrB2–Al2O3 (ZSA) ceramics are prepared by pressureless sintering. In ZSA ceramics, ZrB2 and SiC are the absorbers and Al2O3 is the matrix. The effect of the content of SiC on microwave absorption properties for the ZSA ceramics are studied. The results show that the addition of SiC enhances the MA properties and high-temperature stability of ZrB2–Al2O3 ceramics. Ceramics with an effective absorption bandwidth (EAB) of 3.9 GHz at a thickness of 1.56 mm; and a minimum reflection loss (RLmin) of −15 dB is obtained. After treatment at 1000 °C for 20 h in an air atmosphere, the EAB reduces to 3.5 GHz at the thickness of 1.56 mm, however, RLmin reaches −21 dB. ZSA ceramics consume microwaves through effect including interfacial polarization relaxation, conductive loss and multiple reflection loss. This work is expected to provide new ideas for the design and development of high-temperature microwave absorbing materials.

Structure and properties of hot-forged powder steel–bronze bimetal with SiC additives

Structure and properties of hot-forged powder steel–bronze bimetal with SiC additives

Microstructure and wear resistance of SiC strengthened laser cladded Inconel625-Nb4-SiCx composite coatings

The Inconel625-Nb4-SiCx composite coatings with SiC content ranging from 0 to 2.4 wt% were fabricated through the laser cladding technology. The microstructure of the coating was characterized and the properties of the coating were fully tested. The addition of SiC promoted the generation of M(Nb, Mo)C and Cr23C6 in the coating and improved the homogeneity of the microstructure. The microhardness distribution of the samples could be divided into four zones in order: substrate, heat affected zone, fusion zone and coatings. Similarly, the microhardness of the coatings gradually improved as the SiC content increased, and 2.4SiC coating obtained the highest microhardness, which was 58.2 % above the substrate. The friction test results indicated that the increasing SiC had a constructive impact on the friction performance of the coatings, namely, the wear rate of the coatings was decreased over the substrate by 20.7 %, 36.7 %, 44.6 %, 60.1 % and 70.1 % in order. The wear mechanism shifted from grievous adhesion, oxidation, and fatigue wear in the substrate to mild adhesion and oxidation wear in 2.4SiC coating. This work investigated SiC enhanced In625/Nb/SiC composite coatings and provided a new solution for repairing and improving the performance of In625.

Multi-objective optimization of heat treatment criteria on the corrosion and wear behaviour of ZA27/SiC/TiB2 hybrid metal matrix composite

The current study presents a methodology for examining the effect of solutionizing and aging parameters on the wear and corrosion behaviour of ZA27/SiC/TiB2, a Hybrid Metal Matrix Composite(HMMC). ZA27 alloy is widely used in applications where high bearing resistance and wear resistance properties are desired. However, its usability is limited to temperatures less than 1000 C as its properties exhibit a declining trend. The addition of SiC and TiB2 were found to contribute in circumventing this lacuna. Furthermore, no studies were reported on the process of augmenting the corrosion and wear resistance of this hybrid composite. This research gap is specifically addressed in this work. The chosen Hybrid Composite consisting of 15% of reinforcing elements(SiC + TiB2) proportioned equally among them along with 85% of ZA27 alloy matrix is produced by Mechanical Stir casting method. The experimental work has been broadly divided into two major spectrums. The first part consisting of analysing the change in properties being studied before and after heat treatment. Besides, this part of the work also involved the study of the variation in artificial aging temperature on the properties under consideration. The Potentiodynamic Polarisation tests showed that the solution heat treatment produces a significant decline in corrosion rate. Further, aging at a temperature of 1800 C has also evidently improved the properties of corrosion and wear resistance. However, results also depicted that over aging would deteriorate these properties. The final and subsequent part was completely devoted to identifying the best and optimised heat treatment parameters viz., solutionising time, aging temperature and time. Further, Taguchi L9 orthogonal array is taken to design the experiments in the second phase. Regression Equations were developed from the observations of this set of experiments. These equations were later subjected to Multi-Objective Genetic Algorithm (MOGA) which produces a pareto set of optimal solutions. The Pareto frontier was then analysed using Multi criteria decision making approaches viz., VIKOR, LINMAP and TOPSIS to arrive at the most optimal solution. This approach has culminated in an optimal solution of corrosion and Wear rates of 2.27mpy, 2.75 ˟ 10-3 mm3/m and coefficient of friction as 0.271 at the input variables of solutionizing time −5 h, aging temperature-1890 C and aging time-2 h.

Effect of SiC addition on laser-based CoNi binary alloy coatings on Ti-6Al-4V alloy

This research explores the impact of variations in laser scanning speed and the incorporation levels of SiC-Ni-Co powders on Ti-6Al-4V alloy using laser surface cladding technique. Key parameters, including a consistent laser power of 700 W, a 4 mm beam spot size, a powder feed rate of 1.0 g/min, and a gas flow rate of 3 L/min, along with fixed powder compositions, were maintained. The laser scanning speeds were adjusted to 0.4 m/min, 0.8 m/min, and 1.2 m/min. Microstructural analyses were carried out using scanning electron microscopy (SEM) while Vickers microhardness was employed to assess coating hardness, and corrosion properties were evaluated using a linear potentiodynamic polarization technique. Following the corrosion attack, the protective oxides formed were identified through SEM and X-ray diffractometer (XRD). The results revealed a strong metallurgical relationship between the clad layer and the substrate, demonstrating the effectiveness of the laser-clad technique. Particularly, the highest laser scan speed exhibited the most significant improvements in hardness and corrosion resistance. The coatings displayed an average hardness value of 1269.20 HV0.1, a notable fourfold increase compared to the substrate's value of 334 HV0.1. Concerning corrosion, a clear correlation emerged between scan speed and polarization resistance, confirming that higher scan speeds could lead to enhanced polarization resistance.

Superior ablation resistance of C/C–HfC[sbnd]SiC composite sharp leading edges above 2500 °C prepared by precursor infiltration and pyrolysis

HfCSiC-modified carbon/carbon composite (C/C–HfCSiC) sharp leading edges (SLEs) were prepared via precursor infiltration and pyrolysis for potential hypersonic applications. The effect of SiC proportion on the ablation behavior of the SLEs under oxyacetylene flames with 2.38 MW/m2 and 4.18 MW/m2 was investigated. The preferred sample with a volume ratio of HfC to SiC of 0.74 possessed almost zero degradation (linear recession rate 0.6 μm/s) up to a temperature of 2371 °C. As the temperature increases to 2527 °C in the latter condition, the SLE with less SiC (the volume ratio of HfC to SiC is 1.10) exhibited a linear recession rate of 1.03 μm/s during cyclic ablation of 3 × 40 s. Relatively more SiC addition is favorable under lower heat flux due to the better oxygen barrier performance of the scale. However, superior ablation resistance is available under higher heat flux with less SiC addition due to the higher thermal stability of the resulting oxide scale.

Preparation of coal gangue based foamed ceramics with SiC as blowing agent and study on its thermal insulation performance

The main objective of this study was to utilize coal gangue as the primary raw material and SiC as the foaming agent to successfully prepare foamed ceramics using the high-temperature foaming method. The study investigated the composition and crystal phases of the foamed ceramics formulation, the influence of sintering parameters on the microstructure and physical properties of the samples, as well as the reaction mechanisms during the foaming process. The experimental results showed that when the SiC addition amount was 2.5 wt%, the sintering temperature was 1230°C, and the sintering time was 60 min, the bulk density of the foamed ceramics reached as low as 0.414 g/cm3, with a compressive strength of 1.64 MPa and a closed porosity as high as 74.86%. Additionally, the water absorption and thermal conductivity were simultaneously reduced to 1.48% and 0.1968 W/(m·K), respectively. Besides maximizing the utilization of coal gangue, foamed ceramics also demonstrated excellent porous structure and physical properties, making them suitable for use as thermal insulation materials.

The influence of Co and SiC on the sintering, microstructure and tribological properties of (Ti1/3Zr1/3V1/3)B2 medium-entropy diboride-based ceramics

The (Ti1/3Zr1/3V1/3)B2(MEB) composite ceramics with various Co and SiC additions were prepared by spark plasma sintering technology at 1600 °C. The influence of Co and SiC on the microstructure and mechanical properties were studied. Reciprocating sliding wear experiments of boride ceramics sliding against GCr15 ceramic were also performed at 1 N, 5 N and 10 N (Temperature: 25 °C, frequency: 3 Hz, stroke: 1 mm). The result suggest that the sintering additives not only significantly reduces the sintering temperature of boride ceramic, but also refines the microstructure and improves its mechanical properties. The hardness and fracture toughness of MEB-20SiC–10Co ceramics are 27.76 GPa and 3.9 MPa m1/2, 30.6 % and 60 % higher than that of MEB, respectively. The increase in fracture toughness results from crack deflection and branching of the SiC particles. Tribological results indicates that MEB-20SiC–10Co also show the best tribological performance. The wear rate of MEB and MEB-20SiC–10Co at 10 N load are 2.17 × 10−6 mm3N−1m−1, 1.29 × 10−6 mm3N−1m−1, oxidative wear and adhesive wear are the main wear mechanisms. Analyzing of the wear tracks revealed a significant transfer of material from the counterpart to the tribo-interface. A friction film consisting mainly of titanium oxide and part of boron oxide was generated on the worn surface, which contributes to the improvement of tribological performance.

ДОСЛІДЖЕННЯ ЩІЛЬНОСТІ МАКРОСТРУКТУРИ ВИЛИВКІВ ІЗ ВТОРИННОГО СПЛАВУ СИСТЕМИ AL-SI ПРИ МОДИФІКУВАННІ ВИСОКОДИСПЕРСНИМ КАРБІДОМ КРЕМНІЮ

The study analyzes the impact of modifying a secondary aluminum casting alloy of the Al-Si system with high-dispersion silicon carbide on the density of the metal and the macrostructure of cylindrical castings. It was found that the solidification rate and the structure of the metal depend on the type of mold (metal or sand-clay) and the amount of added SiC. Alloys with a 0.1% SiC addition, cast in a metal mold, have the highest density. The macrostructure of SiC-modified castings is characterized by the presence of deep shrinkage cavities and concentrated porosity. Castings poured into a sand-clay mold with SiC modification show concentrated shrinkage and gas pores, which corresponds to a low grade on the reference scale. The study highlights the importance of choosing the casting method and alloy modification to optimize the density and structure of the castings.