Behavior Of Graphite Research Articles

Macroscopic perspective on phase transition behavior of natural single-crystal graphite under different pressure environments

Comprehensive understanding of the direct transformation pathway from graphite to diamond under high temperature and high pressure has long been one of the fundamental goals in materials science. Despite considerable experimental and theoretical progress, current experimental studies have mainly focused on the local microstructural characterizations of recovered samples, which has certain limitations for high-temperature and high-pressure products, which often exhibit diversity. Here, we report on the pressure-induced phase transition behavior of natural single-crystal graphite under three distinct pressure-transmitting media from a macroscopic perspective using in situ two-dimensional Raman spectroscopy, scanning electron microscopy, and atomic force microscopy. The surface evolution process of graphite before and after the phase transition is captured, revealing that pressure-induced surface textures can impede the continuity of the phase transition process across the entire single crystal. Our results provide a fresh perspective for studying the phase transition behavior of graphite and greatly deepen our understanding of this behavior, which will be helpful in guiding further high-temperature and high-pressure syntheses of carbon allotropes.

Nanoscale friction and wear of graphite surface in ambient and underwater conditions

The tribological properties of graphite are extremely sensitive to surrounding environment, which affects its longevity and friction reduction performance. This study aims to develop a comprehensive understanding of the effects of a liquid environment on interactions at the sliding interface, thereby influencing the nanoscale tribological properties of graphite surfaces. By combining atomic force microscopy experiments and molecular dynamics simulations, we conducted a comparative analysis of friction and wear behavior of graphite under two different environmental conditions: ambient (air) and underwater condition. Our investigations explored both the step edge and interior (step-free) graphite surfaces. The experimental results revealed a notable contrast in the frictional and wear behavior of graphite at nanoscale in these two environments. The interior surface exhibited a friction coefficient (COF) of approximately 0.003 and 0.006 against a diamond-coated surface in ambient and underwater conditions, respectively. Interestingly, the underwater environment not only increased friction but also significantly compromised the wear resistance of graphene layers near the graphite surface compared to the ambient environment, as evidenced in both step edge and interior step-free regions. The interior region sustained up to ∼7400 nN load in ambient condition but failed at ∼1500 nN under water. Similarly, the step edge failed at ∼375 and ∼187.5 nN in ambient and underwater conditions, respectively. Our simulations revealed that the increased friction in underwater condition is due to resistance of surrounding water molecules during tip sliding. The presence of water at tip-graphite contact interface generated substantial localized stress, leading to the initiation of wear and revealing the pronounced effect of water on the wear characteristics of graphite in underwater condition.

3D analysis of crack propagation in nuclear graphite using DVC coupled with finite element analysis

The initiation and propagation of cracks within nuclear graphite components compromise the lifespan of advanced gas-cooled reactors and even lead to safety incidents. A thorough understanding of fracture properties in nuclear graphite is crucial for the effective management and design of graphite structural components. In this work, an in-situ test of a double cleavage drilled compression (DCDC) specimen was conducted using X-ray tomographic imaging to fully analyze the 3D crack propagation behavior in IG-11 nuclear graphite. “Subvolume Splitting” digital volume correlation (SS-DVC) was employed to accurately quantify the displacement fields surrounding the crack. The entire 3D crack propagation and crack surface around the crack front were precisely captured through 3D imaging processing of the gray level residual (GLR) field. Additionally, crack opening displacements (CODs) and stress intensity factors (SIFs) were determined using finite element (FE) analysis with extended finite element method (XFEM). Experimental results indicate that although mode I crack remains predominant throughout the whole process, complex crack propagation exists around the crack front. The utilization of irregular crack surfaces in FE analysis helps to obtain refined displacement fields and accurate SIFs of the crack front. This work provides comprehensive insights into crack propagation and reveals the influence of complex crack morphology on SIF calculations, facilitating accurate prediction of structural integrity and rational design of graphite components.

Elucidating the impact of non-spherical morphology on kinetic behavior of graphite using single-particle microelectrode

The precise assessment of the kinetic properties of graphite is crucial for the design of the material and the development of electrochemical models for lithium-ion batteries. However, conventional evaluation methods using composite electrodes fall short in excluding the influence of its porous structure and evaluating the influence of particle shape on kinetic behavior. In this work, we elucidate the impact of non-spherical morphology on kinetic behavior of single artificial graphite particle, employing the single-particle microelectrode technique. Three single artificial graphite particles with different sizes are pre-cycled and exhibit outstanding rate capability, maintaining a maximum capacity retention of 78.1 % at 200 C. Further, exchange current density and diffusion coefficients are determined through Tafel plots and the potentiostatic intermittent titration technique (PITT), respectively. It is found that the particle with a higher exposure of edge planes present elevated exchange current density and diffusion coefficients. Considering that the graphite particles typically feature an ellipsoidal rather than spherical shape, we propose an approach based on an ellipsoidal diffusion model for extracting diffusion coefficients. This model takes into account the non-spherical morphology of graphite, addressing the limitations inherent in the geometric assumptions of previous methods. The average relative error between the diffusion coefficients derived from the ellipsoidal diffusion model and the previous method using spherical assumptions is 215 %, indicating that accurately depicting the shape of ellipsoidal graphite particles in the model is crucial for obtaining correct estimates of kinetic parameters. This study offers direct experimental evidence of superior kinetic behavior of edge planes over basal planes. To leverage this characteristic, it is recommended to employ an out-of-plane aligned architecture for composite electrodes using novel techniques, e.g., 3D printing or magnetic alignment techniques.

Deciphering the Impact of Current, Composition, and Potential on the Lithiation Behavior of Graphite in Silicon-Graphite Anodes

Graphite is the most used anode material for current-generation lithium-ion batteries due to its beneficial cycle life, availability and reasonable rate capability. Still, the modest capacity of 372 mAhg-1 represents a bottleneck in the pursuit of high-energy density anodes. Enabling much higher theoretical capacities of 3600 mAhg-1 [1], silicon represents a promising candidate as anode material for next generation batteries. However, the alloying-based lithiation mechanism of silicon is accompanied by a large volumetric change of up to 300% upon cycling, leading to fast degradation due to electrode pulverization, continuous SEI formation and extensive electrolyte consumption. Even though shallow cycling of silicon anodes has been demonstrated in laboratory scale cells [2], the mixing of silicon with graphite is considered the most viable approach to lift energy density while maintaining appropriate cycle life.Due to the fundamentally different kinetics and potentials of Li insertion and extraction of both materials, the development of silicon-graphite composite electrodes is not straightforward. One of the key questions for optimization is how the incorporation of silicon impacts the (de)lithiation behavior of graphite as a function of the silicon:graphite mass ratio, operating current and electrode potential. While lithiation of graphite in composite electrodes of 15 wt% silicon has been shown to occur in a similar manner as pure graphite, higher fractions of silicon are expected to exert more stress on the graphite and represent kinetic barriers for Li diffusion. This study presents results from in-situ X-ray diffraction experiments (XRD) of silicon-graphite/Li half cells conducted at the European Synchrotron Radiation Facility (ESRF). Serving as a reference, the current-dependent (de)lithiation behavior of a pure graphite/Li half cell has been thoroughly investigated and systematically compared to the (de)lithiation behavior of two selected silicon-graphite composite anodes (silicon:graphite ratio of 30:70 and 70:30, respectively) exposed to the same formation cycle and C-rate protocol. An optimized and novel measurement setup was used, based on a perforated current collector of the anode, providing a complete picture of the graphite in-plane and interplanar structural changes as well as the evolution of semicrystalline silicon peaks which would usually be obscured by the current collector signal.By correlating the electrochemical features (voltage curve and differential capacity plot) with the in-situ diffraction data, it was possible to identify and assign the occurrence and absence of dilute-stage and ordered graphite intercalation compounds (GICs) for the respective electrodes, yielding an in-depth insight into the graphite state of charge upon (de)lithiation and how it is influenced by the silicon content and applied C-rate.As expected, the silicon is (de)lithiated within the entire potential range, whereas graphite is most electrochemically active at potentials lower than 260 mV. In both composite electrodes, graphite attains a lower lithiation degree compared to pure graphite. This is because the high theoretical capacity of silicon results in high specific currents, ultimately challenging the rate capability of graphite. Moreover, the high delithiation overpotential encountered in the composite electrodes results in a highly asymmetrical lithiation/delithiation behavior of graphite. Also, graphite lithiation is less uniform in the composite anodes, indicated by the coexistence of dilute GICs upon (de)lithiation, compared to pure graphite where dilute phases are fully consumed (formed) as (de)lithiation progresses. Surprisingly, the in-situ XRD studies did not reveal signs of structural degradation and strain of graphite as a result of mechanical interaction with silicon. Instead, the volume change of graphite is well correlated with the amorphization of crystalline, unreacted silicon and the volume evolution of silicon crystallites upon charge-discharge.To mitigate the observed effects, the work suggests nanostructuring and advanced electrode architectures towards higher utilization and more homogeneous lithiation of graphite. Overall, the study provides a demonstration of a suitable operando cell for studies of anodes for Li-based systems, and aids the rational design of silicon-graphite composite anodes.

Microwave-Assisted Morphological Evolution and Thermal Behavior of Expanded Graphite Interlayered Compounds

Microwave-Assisted Morphological Evolution and Thermal Behavior of Expanded Graphite Interlayered Compounds

Effect of carbonization methods on graphitization of soft and hard carbons

Pressurized carbonization is known to improve carbon content and create textural changes in resultant carbon compared to conventional (atmospheric) carbonization. However, further studies investigating the impact of these carbonization methods on the graphitic quality of the carbon precursors have not been explored extensively. This study investigates the influence of carbonization methods on the graphitization behavior of soft and hard carbons using a three-model system: phenolic resole (hard carbon), polyvinyl chloride (PVC) (soft carbon), and a 50:50 blend of resole and PVC. Carbonization was conducted under autogenic pressure (AGP) and atmospheric pressure (APP) at 500 °C for 5 h, followed by high-temperature treatment at varying temperatures. Various techniques, including X-ray diffraction and Raman spectroscopy showed hard carbon precursors exhibited improved properties under AGP carbonization such as larger crystallite size, sharp crystalline peaks, lower ID/IG ratio, and narrow G-full width half-maximum, an indication of improved crystallinity by lowering amorphous phase at high temperature. For soft carbon precursors, the method of carbonization did not impact the graphitization level. The most significant finding was the enhanced crystalline nature observed in hard carbon under AGP conditions, without the need for any catalyst. It shows the influence of pressure on improving the crystallinity of hard carbon precursors.

Lithium Redistribution Mechanism within Silicon-Graphite Electrodes: Multi-Method Approach and Method Validation

Li redistribution processes within Si-graphite composite (SiG) electrodes are analyzed using in situ and operando X-ray diffraction (XRD), ex situ light microscopy (LM), in situ optical microscopy of cross-sectioned full cells (CS-IOM), and 3D microstructure-resolved simulations of full cells. First, the lithiation behavior of graphite and SiG full cells (Si content 20.8 wt.-%) is analyzed. The results are used as validation of the methods (XRD, LM, CS-IOM, simulation). Second, the Li redistribution between the graphite component and Si component within SiG electrodes is investigated: By operando XRD measurements during charging in comparison with relaxed cells, a higher lithiation degree in the graphite component is found during charging compared to the relaxed state, indicating Li redistribution from graphite to Si during relaxation. The Li redistribution is directly observed by in situ and ex situ optical microscopy, where the golden LiC6 phase disappears during a 24 h relaxation period. The results are supported by simulations showing the variation in the Li concentration, not only in graphite but also within the Si component. Furthermore, all methods find that the Li redistribution is more pronounced at a higher C-rate of 0.5 C, suggesting a preference for graphite lithiation over Si lithiation.

Alkali-fluoride-salt-accelerated oxidation behavior of graphite under air atmosphere

Air ingress accident scenarios may result in the oxidation of graphite matrix materials and cause serious safety problems in molten salt reactor. However, the oxidation behavior of the molten-salt-infiltrated graphite remains elusive. In this study, the effect of alkali fluoride salts (LiF, NaF, KF and ternary salt FLiNaK) on the oxidation behavior of graphite powder under air atmosphere was investigated. Thermogravimetric analysis and oxidation tests manifest that the initial oxidation temperature of the graphite is reduced from 720 °C to 510–610 °C, because of the presence of the alkali fluoride salts. The catalytic oxidation effect follows the order of KF > NaF > LiF. Careful characterizations reveal that the pristine graphite is mainly oxidized at the graphite edges, while salt-infiltrated graphite is mainly damaged at the graphitic basal planes. Density functional theory calculations suggest that the doping of alkali metal atoms does not change the physical adsorption feature of the oxygen molecule on the graphite plane surface, but increases its adsorption energy to facilitate the graphite oxidation reactions.

Catalytic Graphitization by Nickel Nitrate and Characterization on Palm Oil Solid Waste Graphite

Abstract Catalytic graphitization of biomass has been extensively studied. The conventional graphitization method uses high temperatures and non-renewable carbon sources. Temperatures below 1000°C was used in biomass graphitization. The aim of this study is to how these variables affect the structural and morphological properties of the graphite materials produced. In graphite production process, catalyst impregnation is followed by heat treatment. The graphitization process starting with amorphous carbon nanospheres, is investigated by Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD) studies. XRD was used to examine the graphitization behavior of palm oil solid waste. Based on the result, the position of the 2 theta peak intensity on the XRD graph of the Ni graphitized sample is extremely near to that on the XRD graph of the raw material and carbon sample. The morphological changes that occur in the SEM images for materials graphitized with nickel nitrate are characterized by structures comparable to those that occur in carbon samples. The circular structures in the graphitized sample are anisotropic and structured without orientation bias.

Additive manufacturing of high-quality NiCu/diamond composites through powder bed fusion

Diamond composites exhibit exceptional hardness, chemical stability and thermal conductivity, but poor machinability limits their widespread applications. This work for the first time reported the use of electron beam melting technique for powder bed fusion (PBF) of 3D-structured NiCu/diamond composites, resulting in a high relative density (>95 %) and avoidance of graphitization, thereby offering overall excellent mechanical properties. Detailed analyses of the interactions between electron beams and NiCu/diamonds revealed that adjusting the linear energy density (LED) can control densification and local graphitization behavior. A dimensionless volumetric energy density (DVED) range derived from a semi-quantitative model has been proposed. The optimized values of DVED (4.1＜ED*＜5.1) are useful guideline for producing metal/diamond composites with complex 3D geometries for various engineering applications.

Abnormally High Graphitic Crystallization of Cellulose Nanocrystals.

Cellulose nanocrystals (CNCs) are currently of great interest for many applications, such as energy storage and nanocomposites, because of their natural abundance. A number of carbonization studies have reported abnormal graphitization behavior of CNCs, although cellulose is generally known as a precursor for hard carbon (nongraphitizable carbon). Herein, we report a spray-freeze-drying (SFD) method for CNCs and a subsequent carbonization study to ascertain the difference in the structural development between the amorphous and crystalline phases. The morphological observation by high-resolution transmission electron microscopy of the carbonized SFD-CNC clearly shows that the amorphous and crystalline phases of CNC are attributed to the formation of hard and soft carbon, respectively. The results of a reactive molecular dynamics (RMD) study also show that the amorphous cellulose phase leads to the formation of fewer carbon ring structures, indicative of hard carbon. In contrast, the pristine crystalline cellulose phase has a higher density and thermal stability, resulting in limited molecular relaxation and the formation of a highly crystalline graphitic structure (soft carbon).

Origin of the surface facet dependence in the thermal degradation of the diamond (111) and (100) surfaces in vacuum investigated by machine learning molecular dynamics simulations

We perform machine learning molecular dynamics simulations to gain an atomic-level understanding of the dependence of the graphitization and thermal degradation behavior of diamond to the (111) and (100) surface facets. The interatomic potential is constructed using graph neural network model, trained using energies and forces from spin-polarized van der Walls-corrected density functional theory calculations. Our results show that the C(111) surface is more susceptible to thermal degradation, which occurs from 2850 K through synchronized bilayer exfoliation mechanism. In comparison, the C(100) surface thermally degrade from a higher temperature of 3680 K through the formation of sp1 carbon chains and amorphous sp2-sp3 carbon network. Due to the dangling bonds at the step edges, the stepped surfaces are more susceptible to thermal degradation compared to the corresponding flat surfaces, with the stepped C(111) and C(100) surfaces thermally degrading from 1810 K and 3070 K, respectively. We propose potential applications of this study in diamond tool wear suppression, diamond polishing, and production of graphene directly from the diamond surface.

Effect of Sample Geometry on Graphitization of Polyacrylonitrile.

In this study, it is analyzed how sample geometry (spheres, nanofibers, or films) influences the graphitization behavior of polyacrylonitrile (PAN) molecules. The chemical bonding and changes in the composition of these three geometries are studied at the oxidation, carbonization, and graphitization stages via scanning electron microscopy (SEM), in situ thermogravimetric-infrared (TGA-IR) analysis, elemental analysis, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The influence of molecular alignment on the graphitization of the three sample geometries is investigated using synchrotron wide-angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM). The effects of molecular alignment at different draw rates during spinning are explored in detail.

Effects of Impurities and Additives on Interactions of Nuclear-Grade Graphite with Molten LiF-NaF-KF

It has been widely acknowledged that the presence of impurities in molten fluoride salt can alter the salt/material interactions. However, the effects of various impurities such as oxides, metal fluorides, reducing impurities, etc., on the behavior of nuclear-grade graphite in molten fluoride salts have not been reported. This study focuses on understanding the effects of various oxidizing and reducing impurities on the wetting and infiltration behavior of molten FLiNaK salt for nuclear-grade IG-110 graphite. Our results suggest that different impurities can cause different effects on nuclear graphite–molten salt interactions, with some impurities leading to significant degradation of the graphite. Our results demonstrate that certain impurities, such as Cr2O3 and CrF3, lead to a limited increase in wetting and infiltration of molten salt into nuclear graphite, while impurities such as Li2O lead to significantly increased wetting and infiltration throughout the cross section of the graphite specimen. Certain impurities, such as Li, can also lead to significant degradation of the graphite in the salt, with the extent of degradation increasing with the increase in the quantity of Li added. Our results also demonstrate that firing of IG-110 graphite at 900°C under a reducing atmosphere made the graphite surface resistant to wetting by molten FLiNaK salt, as compared to the nonfired sample.

Tuning thermal and graphitization behaviors of lignin via complexation with transition metal ions for the synthesis of multilayer graphene-based materials.

Thermal conversion of kraft lignin, an abundant renewable aromatic substrate, into advanced carbon materials including graphitic carbon and multilayer/turbostratic graphene has recently attracted great interest. Our innovative catalytic upgrading approach integrated with molecular cracking and welding (MCW) enables mass production of lignin-derived multilayer graphene-based materials. To understand the critical role of metal catalysts in the synthesis of multilayer graphene, this study was focused on investigating the effects of transition metals (i.e., molybdenum (Mo), nickel (Ni), copper (Cu), and iron (Fe)) on thermal and graphitization behaviors of lignin. During the preparation of metal-lignin (M-lignin) complexes, Fenton-like reactions were observed with the formation of Fe- and Cu-lignin complexes, while Ni ions strongly interacted with oxygen-containing surface functional groups of lignin and Mo oxyanions weakly interacted with lignin through ionic bonding. Different chelation mechanisms of transition metal ions with lignin influenced the stabilization, graphitization, and MCW steps involved in thermal upgrading. The M-lignin complex behaviors in each of the three steps were characterized. It was found that multilayer graphene-based materials with nanoplatelets can be obtained from the Fe-lignin complex via MCW operation at 1000 °C under methane (CH4). Raman spectra indicated that Fe- and Ni-lignin complexes experienced a higher degree of graphitization than Cu- and Mo-lignin complexes during thermal treatment.

Temperature Influence on the Staging Process in Carbon Materials during Anionic Intercalation

A typical set-up of a dual-carbon battery consists of a pair of carbon electrodes and an organic-based electrolyte with a broad window of electrochemical stability. When such a cell is being charged to a reasonably high voltage, two processes occur: intercalation of cations at the electrode with low potential, and intercalation of anions at the one with high potential [1-2]. Although there are significant limitations for practical application of such systems, mostly related to electrolyte decomposition and exfoliation of carbon, the concept appears to be rather inspiring for investigations, as the materials required for dual-carbon batteries would be significantly cheaper compared to those for state-of-the-art electrochemical energy storage solutions.The general idea of using carbon as a cathode material is known for many decades, however, most of the studies dedicated to it pursue the improvement of specific electrochemical characteristics through variation of the cell materials, mostly by trial and error approach [3-4]. Clearly, the results of such research are highly important, but the topic itself lacks the knowledge of electrochemical kinetics for the process of various anions being inserted into graphitic materials, which are typically used as dual-carbon battery cathodes.In our work, we attempted to overcome the limiting factor of electrolyte decomposition by selecting a relatively unusual organic sulfones as solvents. Addition of a salt reduces the melting point of the sulfone, allowing to consider the system as a classic liquid electrolyte. Such cells are known to sustain the high voltages long enough to conduct the studies on structural evolutions which occur in the graphite cathode [4]. We selected two commercial graphitic materials and subjected them to anionic intercalation in various alkali-based electrolytes. Galvanostatic cycling with intermittent titration was conducted to evaluate the diffusion coefficients of anion insertion. The best-performing system was also studied in operando X-ray diffraction cells using the synchrotron radiation facilities, so anionic diffusion was coupled to different stages of intercalation. The staging process itself appears to be completely different at evaluated temperature. Thus, the experiment with KPF6 electrolyte at 298 K showed similar results with the work [5], with subsequent formation of intercalated stages down to stage 2 (see the figure), whereas at 358 K, multiple stages are present together almost from the beginning of intercalation process.The results of the current study show a drastic influence of temperature on the structural behavior of graphite during anionic intercalation, and by electrochemical methods, the kinetics of these changes is characterized, which is necessary for further development of dual-carbon battery topic. R. T. Carlin, H. C. De Long, J. Fuller, and P. C. Trulove, J. Electrochem. Soc., 141, L73, 1994.R. Santhanam and M. Noel, J. Power Sources, 76, 147, 1998.L. Zhang, J. Li, Y. Huang, et al., Langmuir, 35(11), 3972-3979, 2019.M. Tebyetekerwa, T. T. Duignan, Z. Xu, et. Al, Adv. Energy Mater. 12, 2202450, 2022.J. A. Seel and J. R. Dahn, J. Electrochem. Soc. 147, 892, 2000. Figure 1

Determining the oxidation behavior of matrix graphite

This work presents the oxidation behavior of matrix graphite in air. Matrix graphite, graphite powder/flakes bonded by a small amount of non-graphitic carbon, surrounds coated fuel particles in order to form cylindrical fuel compacts (in prismatic core designs) or spheres (in pebble-bed reactor designs). This work focuses on oxidation tests conducted on two matrix graphite materials, one provided by Kairos Power and the other A3 matrix graphite. Some of the tests followed American Society for Testing and Materials (ASTM) oxidation testing standards using a vertical furnace system and others were performed in a thermogravimetric analyzer (TGA). It was determined that, at temperatures of 450 °C–700 °C, the oxidation rate of the Kairos matrix graphite follows the Arrhenius equation. In comparison with A3 matrix graphite, the Kairos matrix graphite shows better oxidation resistance at high temperatures (≥550 °C), but also a higher oxidation rate at low temperatures. Both the A3 matrix graphite and the Kairos matrix graphite materials may experience preferential oxidation of the partially graphitized binder. An oxygen penetration gradient was also observed when using the three characterization methods (i.e., optical microscope, x-ray tomography [XCT], and density profile by the lathe) enlisted in this research. The oxygen penetration depth increases with decreasing isothermal oxidation temperature, while the center of the oxidized samples (10% weight loss) remains almost untouched even at 500 °C.

Dynamic behavior of porous graphite under laser-induced shocks

The present study focuses on developing reliable numerical models to describe the mechanical behavior of isotropic polycrystalline graphite subjected to laser shocks. Isotropic graphite of nuclear grade, which was extensively used in Beam Intercepting Devices of particle accelerators, is characterized by a high porosity enabling effective absorption of laser-induced shockwaves. Accurate numerical models which aim at describing shockwaves traveling inside porous graphite must take into account the effect of pores on the structural response of the material. In this work the Fu Chang foam material model was calibrated to capture the behavior of R4550 graphite. Based on the foam material model, hydrodynamic simulations were developed and compared to experimental data from literature and from PHELIX experimental campaign.

Tribological performance and mechanical behavior of graphite based hybrid composites reinforced with silicon carbide particulate

This study aimed to investigate the mechanical and Tribological Characterization of aluminum metal matrix composites reinforced with silicon carbide particulates ranging from 10% to 20% and five percentage graphite. The metal matrix composites were fabricated using the stir casting technique at temperatures varying from 800 °C to 1000 °C. The Tribological characteristics were evaluated through pin-on-disk tests conducted under dry slipping conditions at room temperature and velocities of 0.979 m/s, using normal pressures ranging from 10 N to 50 N. The worn surfaces were investigated using scanning electron microscopy to elucidate the wear mechanism. Moreover, the study examined the impact of graphite volume fraction and the inclusion of graphite on the mechanical behavior, specifically hardness and tensile strength. The results indicated that the addition of graphite increased the metal matrix composites wear resistance. It was discovered that the wear rate of graphite-reinforced metal matrix composites was lower compared to silicon carbide particulates reinforced composites. Among the silicon carbide particulates reinforced composites, those with a 15% volume fraction demonstrated superior wear resistance, hardness, and tensile strength. The friction coefficients were also raised while the applied load was decreased by the addition of both 15% silicon carbide particulates and 5% graphite.