Graphene Nanoplatelets Composites Research Articles

Experimental studies on the physical and mechanical properties of modified silica/graphene reinforced polyamide6/copolyester elastomer blend nanocomposites

AbstractCompatibility of epoxy extrusion and injection molding was used to create a series of polyamide6 (PA6)/ copolyester elastomer (CoPe)/nano‐silica (nS) and graphene nanoplatelets (nG) composites. The impact of surface‐modified nanofillers and loading on the composites' physical and mechanical properties were investigated. As a consequence, PA6/CoPe blend with silane‐treated nS and nG composites had a slight drop in elongation but a significant gain in strength and modulus than PA6/CoPe blend. The interlaminar shear strength of the nG‐filled PA6/CoPe blend was increased by up to 33.5%, a maximum of 37.55 MPa, with a 1.5 wt% nG loading. With the 1.5 wt% nG loading on the blend surface, the ep resin compatibilizer assisted in interfacial bonding between the matrix and nanoparticles. The impact strength of the PA6/CoPe blend was found to be greater due to the existence of a tougher PA6 matrix, which was subsequently increased by the addition of nS filler reinforcement in the PA6/CoPe/nS composite. The addition of 1.5 wt% of nG in PA6/CoPe blend improved the tensile strength and elastic modulus by 15.8% and 15.1% compared to PA6/CoPe blend, respectively. Scanning electron microscopic studies revealed that the composite had a continuous PA6 phase and a dispersed CoPe phase. The nS and nG particles were embedded in the PA6/CoPe blend exclusively at 1.5 wt% loading. Microstructure analysis reveals a strong contact between the silane‐treated nS and nG and the polar PA molecules, and it may be responsible for the increased mechanical properties.Highlights 1.5 wt% nanoplatelets (nG) boosted tensile strength by 15.8% in polyamide6/copolyester elastomer blend. nG addition increased elastic modulus by 15.1% in the composite. Nano‐silica reinforcement enhanced impact strength with tough polyamide6 matrix. Silane‐treated nano‐silica and nG improved mechanical properties via strong bonds. Slight reduction in elongation observed with nanofiller addition.

A novel approach to improving the interfacial strength of 3D printed Al–GNP composites by modifying GNP with MgO

In this study, the MgO-coated graphene nanoplatelets (GNP)-reinforced aluminum matrix AlSi10Mg composites are fabricated by mechanical alloying and a 3D printing process. The interfacial structure of GNPs–Al has been investigated using high-resolution transmission electron microscopy, and their strengthening mechanism has been analyzed. A weak amorphous Al2O3 was found at the GNP–Al interface area in the composites made with uncoated GNPs. The structure of amorphous Al2O3 becomes distorted when load transfer is initiated, causing the detachment of GNPs from the matrix. This results in quick failure at the interface between uncoated GNPs and aluminum, restricting its overall strength. Once GNPs are coated with MgO, an Al/C mixing zone forms at the contact area, resulting in increased interface strength. The MgO coating on the GNP serves as a protective barrier, preventing the creation of a weaker amorphous Al2O3 layer at the interface and facilitating direct interaction between the GNP and Al matrix. The stress–strain curve demonstrates a 27.5% enhancement in tensile strength in the MgO-coated GNP–Al composite compared to the composite with uncoated GNPs. The strength is increased while maintaining toughness through load transmission of GNPs, bridging, and enhancing dislocation storage capacity by the Mg-rich phase. This study offers a new reference for strengthening 3D-printed aluminum alloys using GNPs.

Uncovering the thermal conductivity of graphene nanoplatelet composites with interlayers using a Monte Carlo model

Abstract This paper uses Monte Carlo (MC) method to study the thermal conductivity of graphene nanoplatelet (GNP) composites. Firstly, a large number of GNPs are randomly set in a representative volume element (RVE). Then, based on the temperature field satisfying the Laplace equation in the matrix, a coated surface (CS) is set up on each GNP surface, and the temperature of CS and GNP are obtained by a Walk-on-Spheres (WoS) method. Finally, the WoS method continues to be applied to calculate the heat flux density of composite materials, further obtaining the thermal conductivity of the composite. We have incorporated the influence of interlayers in the WoS process and pointed out that walk onto the interlayer surface have a very low probability of getting to GNP due to the extremely low thermal conductivity of the interlayer. The calculated results are consistent with the experimental data. The model also studied the effects of size, orientation, and aggregation of GNP on the thermal conductivity of the composite.

Enhancing the thermal conductivity of polystyrene/polyamide 6/graphene nanoplatelets composites through elongational flow

Migration and distribution of thermal conduct fillers in polymer blend are key factors in the preparation of enhanced thermal conductivity composite. In this study, polystyrene(PS)/polyamides 6(PA6)/graphene nanoplatelets(GNPs) composites with enhanced thermal conductivity were prepared under elongational flow, and the migration and distribution of GNPs were investigated by molecular dynamics simulation and experiments. The results showed that when GNPs immigrate from PA6 phase to PS phase, the elongational flow caused the orientation of the PS phase and GNPs, reducing the migration rate of GNPs from the PA6 phase to the PS phase. At the same time, the stretching viscosity of the PS phase increases, which prevents GNPs entering the PS phase. As a result, GNPs remain within the PA6 phase near the interface of the two phases. The effective distribution density of GNPs increased, making it easier for them to interconnect and form thermal conduction paths, thereby improving the thermal conductivity of the composites. Particularly, the composite prepared under the elongational flow with the 50/50 vol ratio of PS/PA6, the in-plane thermal conductivity of PS/PA6/GNPs composites reached a maximum of 1.64 W/(m·K).

Influence of graphene nanoplatelet on carboxymethyl cellulose for enhanced electrochemical performance

Renewable and bio-based polymers are favored over conventional synthetic polymers because of their low-cost, abundance and sustainability, but due to their average electrochemical performance, sometimes their application is limited as battery material. This study investigates the electrochemical properties of nanocomposites composed of carboxymethyl cellulose (CMC) and graphene nanoplatelets (GNP) at varying GNP ratios. Four samples with GNP weight ratios ranging from 0 to 0.33 wt.% were subjected to analysis using electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy. The sample containing 0.33% GNP exhibited the most favorable electrochemical behavior, demonstrating an ionic conductivity of approximately 2.54 × 10−5 S/cm at 25 °C. Cyclic Voltammogram and Nyquist plots indicated an electrochemical process governed by diffusion processes, particularly evident with 0.33% GNP. This sample displayed the highest specific capacitance at 4.290 F/g, representing an 83.07% improvement over the Pure CMC sample, along with a favorable electrochemical window at 375 mV. Bode plot analysis underscored the influence of diffusion and charge transfer on resistance and conductivity, highlighting enhanced ion mobility in this sample. SEM micrographs revealed improved GNP dispersion in the CMC matrix at higher GNP concentrations, enhancing contact. FTIR analysis confirmed effective CMC–GNP interaction, characterized by a specific peak at 1589 cm−1. These findings provide valuable insights into the electrochemical potential of CMC–GNP composites, offering prospects for their application in diverse electrochemical devices.

Effective Young’s modulus of highly porous 3D printed mono-material and coaxial structures

The dynamic elastic response of 3D macroporous scaffolds is crucial to determine their performance under operating conditions. In this work, the elastic behaviour of 3D printed bar-shaped scaffolds of γ-Al2O3 and γ-Al2O3/graphene nanoplatelets (GNP) composites (18 vol%), fabricated by Direct Ink Writing (DIW), is investigated. Dynamic Young’s modulus (E) is studied by the Impulse Excitation Technique (IET) and compared with theoretical results obtained by Finite Element Methods (FEM) and the multi-scale material simulator GeoDict®. In addition, Resonant Ultrasound Spectroscopy (RUS) is used to characterize E of single- and bi-material coaxial struts. While additions of GNP to γ-Al2O3 lead to an increase in E, it decreases in the coaxial struts due to the development of thermal residual stresses at the core/shell interface. The suitability of combining experimental and theoretical methods for the analysis of the elastic properties and the anisotropy associated with the lattice pattern is demonstrated.

Damping and mechanical behavior of graphene nanoplatelets reinforced Al-30Zn alloy matrix bioinspired laminated composites by two steps flake powder metallurgy

Damping and mechanical properties are often incompatible in metallic materials. In this paper, bio-inspired laminated graphene nanoplatelets (GNPs) reinforced Al-30Zn alloy matrix composites with an outstanding combination of damping-mechanical properties are prepared using a flake powder metallurgy (FPM) process. The increased grain/phase boundary owing to grain refinement improves the intrinsic damping properties of the composites, while the lamellar grains promote the oriented alignment and crack deflection of GNPs. The multilayered GNPs with large specific surface area experienced repeated stretching and compression during cyclic bending deformation, leading to intense interfacial frictional slip, and GNPs' high intrinsic thermal conductivity also helped to dissipate heat quickly, which promoted mechanical energy dissipation. The improvement in mechanical properties is mainly attributed to grain refinement, the load transfer effect of GNPs and their interaction with dislocations. The Al-30Zn-0.5GNPs composites showed the best combination of damping properties and mechanical properties.

Composites with aligned and plasma-surface-modified graphene nanoplatelets and high dielectric constants

We have developed a method for designing polymer and graphene nanoplatelet (GNP) composites that show high dielectric constants over a wide range of GNP contents. GNPs are dispersed in the composites through plasma-surface modification and aligned by applying an electric field (EF). This creates a large number of microcapacitor structures of GNPs separated by the polymer. The maximum dielectric constant of the sample to which the EF is applied is approximately twice that of the sample to which the EF is not applied. Furthermore, the maximum dielectric constants of the samples with plasma-surface modified GNPs are higher than those of the samples with unmodified GNPs. The composites show high dielectric constants (∼500 at 100 Hz) over a wide range of GNP contents (6 ∼ 10 wt%) while maintaining mechanical flexibility (Young’s modulus:12 ± 4 MPa).

The Effects of Indium Additions on Tribological Behavior of Spark Plasma Sintering-Produced Graphene-Doped Alumina Matrix Composites for Self-Lubricating Applications

Alumina (Al2O3) ceramics are interesting for low-weight and mid-high temperature applications. The addition of indium (In) and graphene nanoplatelets (GNPs) can be used to reduce the density and modify the functional properties and mechanical performance of the ceramic matrix. GNP and In-reinforced Al2O3 matrix composites were prepared by the spark plasma sintering (SPS) technique. Monolithic Al2O3 and Al2O3 matrix composites with either 5 or 10 wt.% of In and 2 wt.% of GNPs (Al2O3-5In-2GNPs and Al2O3-10In-2GNPs) were compacted into disc-shaped samples. The microstructure was studied and characterized with light-optical microscopy (LOM) and scanning electron microscopy (SEM). Hardness was determined using the Vickers technique and tribological properties were studied by the ball-on-disk method. The coefficient of friction (COF) and specific wear rates were evaluated from tribological tests. Worn surfaces were studied by SEM and confocal microscopy. Interdiffusion transition regions were formed among individual microstructural constituents (Al2O3, In, GNPs) under high sintering temperatures, which were responsible for the balanced hardness and low porosity of the produced composites. The addition of In and graphene nanoplatelets resulted in smaller COF and wear rates indicating good improvement in the tribological behavior. The prepared Al2O3-5In-2GNP and Al2O3-10In-2GNP composites represent promising nanocomposites for self-lubricating applications.

THE EFFECT OF GRINDING ON OPTICAL BAND GAP AND URBACH ENERGY OF POLYPYRROLE/GRAPHENE COMPOSITES

The goal of this study is to better understand the effect of grinding on the Eg of polypyrrole (PPy)/commercial graphene nanoplatelets (xGnP) composites with varying amounts of xGnP. The Eg for direct transition as a function of the xGnP amount was calculated from the Tauc plot. While the average particle size of the composites decreased between 6% and 30%, there was a slight decrement in the Egs. These values changed between 4.02 to 3.87 eV with the increasing amount of xGnP before grinding, and they reached between 3.97 to 3.88 eV after grinding. Moreover, it was determined that the EU was inversely proportional to Eg. These findings suggest that the PPy/xGnP composites could be suitable for several applications, such as photocatalytic and optoelectronic.

Application of computer simulation to model transient vibration responses of GPLs reinforced doubly curved concrete panel under instantaneous heating

In this article for the first time, with the aid of computer simulation, transient vibration responses of the concrete doubly curved panel exposed to immediate heating are reported owing to the significance of concrete panels used in civil applications. The substrate includes spring element, shear, torsion, and substrate-structure friction factor. A novel model of a two-parameter substrate is introduced in this research with enough flexibility to involve three forms of polynomial, sinusoidal, and cosinusoidal expansion with various terms in its stiffness. With the aid of Halpin-Tsai micromechanics and the well-known rule of mixtures, the material properties of the graphene nanoplatelet (GPLs) composites reinforced doubly curved concrete panels are modeled. As well as this, for accurate modeling of the current work, the thermal conductivity of each continuous GPLs layer along with thickness direction using mathematical simulation is presented. Finally, entropy, the constitutive heat conduction equation, the Heaviside unit step function, and thermal shock loading are used in the final governing equations. The Laplace transform is employed to solve the temporal variation of the system’s response, while its spatial response is determined with the aid of the harmonic differential quadrature approach (HDQA). For more verification of the current work results and due to the lack of research in the field of the transient response of thermally induced vibrations of the panel, the results of the current work are verified with a Machine learning algorithm. Then, in the results section, some recommendations for enhancing the transient vibrations of the present concrete structure will be thoroughly examined.

A theoretical approach for thermomechanical shock analysis of doubly curved panel with respect to geometrical and physical parameters using machine-leaning-based algorithm

In this work, for the first time, bending information of the doubly curved panel under thermo-mechanical shock loading (MSL) with respect to geometrical and physical parameters via both numerically, and machine-leaning-based algorithms is presented. The graphene nanoplatelets composites are used to reinforce the current composite curved panel along with latitudinal direction. It should be note that the current curved panel is reinforced in latitudinal direction with GPLs due to thermo-MSL in the latitudinal direction. The material properties of the current doubly curved structure are obtained with the aid of role of mixture and Halpin–Tsai micromechanics model. As well as this, GPL distribution’s thermal conductivity for each pattern of GPL is considered for high accuracy of the current work’s model. Three-dimension (3D) elasticity theory, linear thermo-elasticity principle, constitutive heat conduction equation, and relaxation time equation are used to present the mathematical modeling of the current work. After obtaining the governing equations, the equations are solved via numerical solution using Chebyshev–Gauss–Lobatto function, and spatial and Laplace latitudinal methods. Deep neural networks (DNNs) as a machine learning method are used to train and test the obtained results from mathematical modeling. After predicting the results, the results are compared with the outcomes of mathematical modeling and show that with the low computational cost of DNNs algorithm, the results can be predicted instead of other high computational cost methods. Finally, some suggestions for improving the thermo-mechanical behavior of the current doubly curved panel under external shock loading.

Preparation of antistatic and biodegradable packaging of PLA/PHBV blend‐based glassy carbon and graphene nanoplatelets composites

AbstractGlassy carbon (GC) and graphene nanoplatelets (GNP) were used as fillers for the preparation of antistatic and biodegradable composites based on poly (lactic acid)/poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PLA/PHBV) blend. In this work, PLA/PHBV (80/20) blends with the addition of different GC contents (0.1, 0.3, and 0.5 wt%) were prepared by melt mixing using a twin‐screw extruder, and specimens were injection molded. Furthermore, hybrid composites were prepared with the addition of 5 wt% of GNP and different GC contents (0.1, 0.3, and 0.5 wt%) using the same processing. The effect of the addition of GC and GNP on the mechanical, electrical, and electromagnetic properties and its effect on the biodegradability of the PLA/PHVB blend was evaluated. The simultaneous addition of GC (0.3 and 0.5 wt%) and GNP (5 wt%) significantly increases the elastic modulus and decreases the electrical resistivity, becoming suitable for electrostatic discharge protection packaging applications. The hybrid composite GC0.5/GNP5 reached a maximum value of total attenuation (4.5 dB), which corresponds to 60% EMI shielding. The degree of crystallinity affects biodegradability more than the type or presence of carbon material. After 110 days of anaerobic biodegradation, the hybrid composite exhibited 10% biodegradability due to the high degree of crystallinity that hinders the biodegradability process. The hybrid composites with the addition of GC and GNP are very promising for use in antistatic packaging.

Mechanical Properties, Degradation Behavior, and Cytocompatibility of Zn–Mg–Graphene Nanoplatelets Composite for Orthopedic‐Implant Applications

Zinc (Zn)‐based materials reveal inadequate mechanical properties as orthopedic biodegradable implantable materials, which limits their biomedical applications. Herein, Zn–xMg (magnesium) composites (x = 0.5, 1.0, 1.5, and 2.0 wt%) reinforced with 0.2 wt% graphene nanoplatelets (GNP) are obtained via powder metallurgy and hot‐pressing sintering. The addition of 0.5–2.0 wt% Mg into Zn–0.2 wt% GNP composite resulted in the formation of Mg2Zn11 and MgZn2 phases without any additional intermetallic carbide phases. The hot‐pressing sintered (HPS) Zn–0.5Mg–0.2GNP composite exhibits a compressive yield strength of 169 ± 18 MPa, an ultimate compressive strength of 270 ± 39 MPa, a compressive strain of 17 ± 6%, and a microhardness of 86 ± 2 HV. Electrochemical corrosion testing reveals that corrosion resistance of HPS Zn–xMg–0.2GNP composites decreases with increasing Mg content, while immersion tests in Hanks’ balanced salt solution for 30 d indicate that the degradation rate increases from 0.032 to 0.141 mm y−1 by increasing Mg content from 0 to 2.0 wt%. In vitro cytotoxicity assessments using SaOS2 human osteoblast cells show >90% viability following exposure over 5 d to 12.5% extract concentrations of all HPS composites. The HPS Zn–0.5Mg–0.2GNP composite exhibits the appropriate material properties for biodegradable bone‐implant applications.

Study of thermal and mechanical behavior by analyzing reinforcement effect of graphene nanoplatelets on polyamide-66 composite system developed via melt-mixing technique

In the present study, graphene nanoplatelets (GNP) reinforced polyamide 6,6 (PA-66) composite was studied to investigate the thermal and mechanical properties of PA-66/GNP composite. The composites were developed by varying wt% (1, 3, 5, and 10 wt%) of GNP loading using a co-rotating, intermeshing, twin-screw extruder via melt-mixing and injection molding process. In order to understand the thermal and mechanical behavior of PA-66/GNP composite, various thermal (TGA and DSC) and mechanical (tensile, impact, and flexural) tests were carried out. The FTIR spectral analysis was done to identify the presence of different functional groups in the PA-66/GNP composite, indicating the strong enough Vander-Waals interaction between the PA-66 matrix and GNP filler contents. The TGA result shows a significant enhancement in the thermal stability of the composite by increasing wt% of GNP. The DSC analysis exhibits a significant reduction in enthalpy of fusion (∆Hm) and a decrease in the degree of crystallinity with increasing wt% of GNP, reflecting a depressed form of α-crystalline structure. Further, the significant growth in tensile modulus and tensile strength were identified under the mechanical performance of the PA-66/GNP composite. An increasing trend in tensile modulus and tensile strength characteristics was observed, and tensile modulus exhibited an enhancement of ∼96% than pure PA-66 at 10 wt% of GNP. Also, the tensile strength is found to be ∼16% higher than that of pure PA-66 matrix. Similarly, the impact test result shows a decreasing trend in impact strength on increasing wt% of GNP reinforcements, indicating the restriction to the molecular mobility due to improved brittle behavior. Further, the flexural modulus is found to be increased by ∼28% at 10 wt%, and the flexural strength is found to have an enhancement of ∼9% at 3 wt% than pure PA-66 polymer matrix of GNP loadings, respectively. The influence of GNP filler content reinforced PA-66 composite on the thermal and mechanical properties is found to be noteworthy.

Study of Galvanic Charging-Discharging Properties of Graphene Nanoplatelets Incorporated Epoxy-Carbon Fabric Composites

Polymer composites are increasing in demand in energy storage applications including in the electronic as well as electrical industries due to the ease of processing of these materials with associated advantages like light weight, corrosion resistance, and high mechanical strength. In this investigation, efforts are made to enhance the charging and discharging properties of epoxy/carbon fabric composite by the addition of graphene nanoplatelets (GNPs) into the epoxy/ carbon matrix. The performance of the composites with graphene platelets of 0.5 to 5 wt. % in epoxy were characterized and 1wt.% percolation threshold was observed poor performance in gravimetric charge and discharge characteristics were observed. Based on the percolation threshold Epoxy-Carbon fabric (EC) composites and Epoxy-Carbon fabric with 1 wt. % of GNP (ECG1) composites were fabricated using a vacuum-assisted resin transfer molding technique. The electrochemical performance was studied using the Cyclovoltammetry test and 0.1 M of Na2SO4 as a supporting electrolyte. The Galvanostatic Charge-Discharge characteristics were carried-out for EC and ECG1 at a scan rate of 80 sec, 300 sec, 4000 sec with 2 runs and 8 runs. The composite EC didn’t not show GCD characteristics, but the symmetry of charge-discharge characteristics observed for ECG1 and same are discussed in this paper. These highly effective and excellent characteristics demonstrate that Epoxy-GNP-CF composites may be promising composites for practical energy storage applications.

Stitched Graphene Nanoplatelet Composites for Unitized Aerospace Structures

Lightweight composites play an important role in sustainability as their usage in aerospace vehicles translates to improved fuel consumption and reduced emissions. However, due to their low interlaminar strength, delaminations and microcracking degrade their strength and stiffness properties. Through-thickness stitching in composites enhances interlaminar properties but reduces the in-plane properties. Graphene nanoplatelets (GNPs) and carbon “thin plies” have been found to increase the mechanical properties of these composite structures. This study considers a hybrid composite that uses GNPs coupled with thin plies at the midplane to mitigate the reduction in the in-plane properties. Composite specimens [+45/−45]4s were stitched with two different seam angles (0 and 90°) and tested under uniaxial tensile loading. Surface strain fields from digital image correlation measurements show a significant decrease in strain concentrations in the hybrid specimens compared to the baseline stitched composites. An increase of 17% in tensile modulus and a reduction of 15% in strain energy density are realized due to the hybrid architecture of the stitched composite.

Microwave heating of graphene nanoplatelet polymer composites: Experimental and finite element study

AbstractCompared with contemporary electrofusion techniques that use embedded wires for Joule heating, microwave heating may facilitate the joining of thermoplastic polymer components, promising shortened fusion periods, superior heating uniformity, and reduced energy consumption. This study investigates the fabrication of multifunctional polylactide acid (PLA) composites with strong microwave absorption using graphene nanoplatelets (GNP). GNP/PLA nanocomposites were fabricated using a two‐step scalable manufacturing method, that is, solution blending and hot compression molding. The GNP content of the composites ranged from 0% to 8% by weight. The samples were characterized for dielectric permittivity, heat capacity, and electrical and thermal conductivity. Thermal imaging was used to investigate the efficacy of microwave heating in GNP/PLA nanocomposites as a function of microwave power and filler weight fractions. The microwave heating process in GNP composites was studied using multi‐physics finite element software. The experimental results were compared to numerical model predictions for maximum temperature and microwave energy absorbed. The produced nanocomposites were discovered to have strong microwave absorption characteristics and hence rapid heating, making this type of composite a prospective choice for gasket materials that facilitate fusion bonding for thermoplastic‐based components via localized heating.

Salt template-assisted construction of three-dimensional interconnected network in thermally conductive EP/PVDF/NiCo@GNP composites

In this study, graphene nanoplatelets (GNP) and nickel–cobalt (NiCo) alloy were adopted as reinforcing materials to prepare epoxy (EP) resin-based composites. NiCo particles were able to achieve uniform anchoring on GNPs’ surface under the electrostatic force due to the successful introduction of oxygen defects on GNPs. With the synergistic effect of adhesive PVDF and salt particles, the system with three-dimensionally (3D) interconnected network was successfully constructed. Benefit from the formation of mechanically stable and efficient heat conduction paths, the thermal conductivity (TC) of the EP/PVDF/NiCo@GNP composite reached 1.077 W⋅m−1⋅K−1 at a filler volume fraction of 6.82 vol%, while the counterpart’s storage modulus (E’) was up to 3.22 GPa. In addition, a scaling formula was quantitatively proposed to correlate TC with E’, and the perfect agreement between the theoretical prediction and experimental data clarified the underlying mechanism of the relationship between phonons transport and stress transfer within a system with 3D ordered structures. The establishment of relationship between AHR (average heating rate) and TC made it possible to further predict TC of composites based upon the infrared thermal imaging (ITI) data. The as-prepared GNP composites show good application prospects as thermal management materials which need to experience thermally mechanical deformation.

The Effect of Graphene Nanoplatelets Content on the Hardness of Mg6%Zn0.2%Mn Composites

The effect of graphene nanoplatelets (GNPs) content on the hardness of magnesium-based composites was studied. A magnesium-based composite, Mg6%Zn0.2%Mn with graphene nanoplatelets (GNPs), was fabricated via powder metallurgy process at room temperature and compressive pressures of 50kN for 20 minutes, which was then sintered at 500°C for 2 hours. It produced significant grain refinement microstructure. The change in microstructure was examined by 3D microscope analysis, and the hardness value was evaluated using the Vickers microhardness apparatus. This study demonstrated the importance of GNPs reinforcement with zinc and manganese for microhardness analysis in the sintered Mg-based GNPs composites. It also portrayed their influence on grain refinement of the microstructure. The hardness results agreed with the microstructure results, proving that the presence of GNPs increases the hardness of the Mg-based composites.