Short Carbon Fiber Content Research Articles

Tailoring the additional content of short carbon fiber in the reduced graphene oxide-Cu self-lubricating composites for enhanced mechanical and tribological performance

The reduced graphene oxide-Cu self-lubricating composites with short carbon fiber fillers were fabricated by powders wet-mixing combined with hot-pressed sintering process. The impacts of short carbon fiber content on microstructure, mechanical and tribological performance of reduced graphene oxide-Cu composites were characterized. The reduced graphene oxide/carbon fiber hybrid fillers were randomly distributed in the sintered bulk compacts. The hybrid filled composites achieved enhancement in mechanical and tribological properties. With increasing carbon fiber content, hardness and compressive yield strength of the prepared composites were increased, and both friction coefficient and wear rate showed a constant decrease trend under different loads. Owing to the synergy effect of reduced graphene oxide/carbon fiber hybrid lubricant fillers during sliding together with the greatly enhanced hardness and yield strength, up to 0.6 wt% carbon fiber incorporation resulted a lowest friction coefficient and decreased wear rate. Randomly distributed reduced graphene oxide/carbon fiber hybrid fillers provided the lubrication to reduce friction and wear for Cu matrix.

Variable orientation in material extrusion of short carbon fiber reinforced polymer composites with high thermal conductivity

Controllable orientation architecture possesses tunable thermal behavior for effective heat dissipation in unidirectional product fields, meanwhile without interference with adjacent components. Herein, we proposed a variable orientation strategy in material extrusion of short carbon fiber (SCF) reinforced polymer composites framework with spatially tunable thermal properties. It was achieved due to the following reasons: (Ⅰ) Inherent shear flow in the nozzle; (Ⅱ) Increasing tensile flow by changing the ratio between the printing speed of monofilament and the feeding speed of filament (Vp/f); (Ⅲ) Further surface tension due to thinning monofilament by varying Vp/f. The SCF with different orientations and content reinforced polyether-ether-ketone (PEEK) composites were successfully fabricated. The microcosmic orientation of SCF could be programmed from a three-layer hierarchical framework to a single-layer oriented framework at different Vp/f. Benefit from variable orientation, the through-plane thermal conductivity of SCF/PEEK composites achieved a thermal conductivity enhancement of 173.9 %. In addition, the simulated application of SCF/PEEK composites in the CPU of the computer showed excellent heat transfer during heating. Further, the thermal conductivity mechanism of the synergistic influence between Vp/f and SCF content was analyzed by cross-sectional microstructure. The proposed strategy in this work for fabricating variable orientation of SCF reinforced polymer composites showcases great application prospects in electronic devices and unidirectional product fields.

Improving mechanical performances at room and elevated temperatures of 3D printed polyether-ether-ketone composites by combining optimal short carbon fiber content and annealing treatment

Development of high performance polyether-ether-ketone (PEEK)) composites is of great significance for aerospace engineering application. The fused filament fabrication (FFF)-based 3D printing process is promising for manufacturing high performance short carbon fiber (SCF) reinforced PEEK composites. However, a comprehensive investigation of the combined effects of SCF content and annealing condition has not been conducted on the mechanical performances of SCF/PEEK composites; also, elevated temperature mechanical properties that are required for aerospace engineering have not been reported for 3D printed SCF/PEEK composites. This work develops a creative strategy that combines the optimal short carbon fiber (SCF) content with annealing treatment to achieve significant improvements in the mechanical properties both at room and elevated temperatures of FFF-3D printed SCF/PEEK composites. First, the influences of SCF content on the mechanical performances of 3D printed SCF/PEEK composites are studied to determine the optimal fiber content (5 wt%) for the best mechanical performances of non-annealed PEEK composites. Then, the effects of SCF content and annealing on room temperature and elevated temperature mechanical performances are examined for both PEEK and the 5 wt% SCF/PEEK composite. It is elucidated that the increase of interface strength and crystalline region as well as the reduction of residual stress by annealing are all responsible for the observed improvements in mechanical performances. This work presents a comprehensive study of 3D printed short fiber reinforced thermoplastics and serves as a valuable reference for the 3D printing of high-performance thermoplastic composites.

Effect of short carbon fiber content on strength and toughness of Al2O3–C refractories

AbstractShort carbon fiber is a promising candidate for reinforcing carbon‐containing refractories at the macro scale due to its excellent high‐temperature stability and mechanical properties. In this work, the microstructure evolution of short carbon fiber and the effect of its addition on the properties of Al2O3–C refractories are investigated. The results show that adding short carbon fiber could affect the distribution of in situ ceramic phases, combined with the cross‐scale reinforcement effect, leading to high strength—the CMOR of short carbon fiber containing refractories could be 23.0% higher than the free ones, while the HMOR could be 22.0% higher. Furthermore, the results suggest that the short carbon fiber containing refractories treated at 1400°C possesses high resistance to the initiation of crack propagation, which could be attributed to the high bonding strength brought by carbon fiber. Noteworthy, adding short carbon fiber could improve thermal shock resistance. The short carbon fiber containing refractories treated at 1300°C could possess a higher residual strength ratio than free ones. For instance, the specimen containing 0.1 wt% short carbon fiber shows the highest residual strength ratio (87.7%).

Interlaminar fracture toughness of carbon/epoxy composites laminates toughened by short carbon fiber

AbstractIn this paper, short carbon fiber (SCF) interlaminar toughened carbon fiber reinforced epoxy resin (CF/EP) composite laminates were prepared. The effect of SCF content on the mode II interlaminar fracture toughness (GIIC) and flexural properties of CF/EP composites was investigated. It was shown that the addition of SCF between the plies had an effect on the GIIC of the composites. When the SCF content was 10 g/m2, the GIIC increased from 1506.62 J/m2 to 1995.6 J/m2, which improved by about 32.46%. When the content of SCF was 5 g/m2, the flexural strength and flexural modulus increased by 36.92% and 98.48%, respectively, showing the best performance. The toughening mechanism of SCF was observed by SEM images as SCF debonding and pulling out from the resin and SCF fracture. The present study was also compared with our previous study on short aramid fiber interlaminar toughened CF/EP composites, and the test data and SEM images of the two experiments were compared to analyze the effect of different short fibers on the interlaminar toughening effect, which provides some reference for the selection of interlaminar toughening materials.

Development of 3D printing short carbon fiber reinforced polypropylene composite filaments

In this study, the 3D printing short carbon fiber (SCF) reinforced polypropylene (PP) composite filament was developed. The micro-size SCFs were mixed with PP granules and extruded in a twin screw extruder to develop SCF/PP composite granules. The composite granules were extruded in a single screw extruder and then wound to develop SCF/PP filaments. SCF/PP filaments were produced with varying content of SCF ranging from 4 to 22 wt%. The developed composite filaments were injected by a 3D printer to produce testing samples. 3D printed SCF/PP composites with different SCF contents were investigated by analyzing their mechanical, physical, and morphological properties. The SCF/PP composites developed have shown great enhancement in their mechanical properties (tensile strength and impact toughness). The tensile strength of the 22%SCF/PP composite increased by 150% when compared to the neat PP, while the impact energy of the 22%SCF/PP composite was enhanced by 260% of the neat PP. However, the strain at break values decreased linearly in composites up to 11 wt% SCF content followed by a sudden drop in strain values in composite with 14 wt% SCF.

Strengthening Effect of Short Carbon Fiber Content and Length on Mechanical Properties of Extrusion-Based Printed Alumina Ceramics.

Extrusion-based ceramic printing is fast and convenient, but the green body strength is too low, and the application prospect is not high. An extrusion-based printing method of alumina ceramics toughened by short carbon fiber is reported in this paper. The bending strength and fracture toughness of 3D-printed alumina ceramics were improved by adding short carbon fiber. The toughening effects of four carbon fiber lengths (100 μm, 300 μm, 700 μm, and 1000 μm) and six carbon fiber contents (1, 2, 3, 4, 5, and 6 wt%) on ceramics were compared. The experimental results show that when the length of carbon fiber is 700 μm, and carbon fiber is 5 wt%, the toughening effect of fiber is the best, and the uniform distribution of fiber is an effective toughening method. Its bending strength reaches 33.426 ± 1.027 MPa, and its fracture toughness reaches 4.53 ± 0.46 MPa·m1/2. Compared with extrusion-based printed alumina ceramics without fiber, the bending strength and fracture toughness increase by 55.38% and 47.56%, respectively.

Additive manufacturing of Csf/SiC composites with high fiber content by direct ink writing and liquid silicon infiltration

Direct ink writing (DIW) provides a new route to produce SiC-based composites with complex structure. In this study, we additive manufactured short carbon fiber reinforced SiC ceramic matrix composites (Csf/SiC composites) with different short carbon fiber content through direct ink writing combined with liquid silicon infiltration (LSI). The effects of short carbon fiber content on the microstructure and mechanical properties of the DIW green parts and the final Csf/SiC composites were investigated. The results showed that the Csf content played an important role in maintaining the structure of the green parts. As the Csf content increases, the dimension deviation ratio of the sample decreased at all stages. With the Csf content of 40 vol%, the final Csf/SiC composite had low free Si content and high β-SiC content. The maximum density, tensile strength and bending strength of the Csf/SiC composites were 2.88 ± 0.06 g/cm 3 , 53.68 MPa and 253.63 MPa respectively. It is believed that this study can give some understanding for the additive manufacturing of fiber reinforced ceramic matrix composites.

Experimental and numerical modal analysis of short carbon fiber reinforced polyethersulfone composites

Damping is the resistance to the vibratory motion. Viscous dampers are generally used to resist the repetitive motion and dissipate the energy out of the vibrating system. However, material of the vibrating body itself will have ability to dissipate the vibratory energy which is often referred as material damping. Even though, material damping is very small compared to viscous damping, in many practical situations, this may also play significant role. This work was focused on the evaluation of material damping of short carbon fiber (SCF) reinforced polyethersulfone (PES) composites by adopting free vibration test methodology. In addition, Young’s modulus of the PES/SCF composites was determined through their natural frequencies. Investigation was made by reinforcing the PES with 10, 20 and 30 wt.% of SCF using twin screw extruder and injection moulding machine. Free vibration response of the clamped-free composite beam was captured through an accelerometer sensor. Free vibration test revealed that PES composites showed reduction in damping with increase in SCF content due to stiffening of the polymer. Natural frequencies of PES composites increased with increase in SCF loading. Tensile modulus enhanced by 267% with respect to neat polymer for 30 wt. % of SCF reinforcement. Also, numerical frequency analysis was carried out using Abaqus finite element package and simulated results closely fitted with the experimental data.

Effect of short carbon fiber content on the mechanical properties of TiB2‐based composites prepared by spark plasma sintering

AbstractIn this study, TiB2‐30 vol% SiC composites containing 0, 5, 10, and 15 vol% short carbon fibers (Cf) were produced by spark plasma sintering (SPS). The effect of carbon fiber content on microstructure, density, and mechanical properties (micro‐hardness and flexural strength) of the fabricated composites was studied. Scanning electron microscopy (SEM) results indicated that the fibers were uniformly dispersed in the TiB2–SiC matrix using wet ball milling before SPS process. Fully dense TiB2–SiC–Cf composites were achieved by SPS process at 1900°C for 10 min under 30 MPa. With the addition of fibers, the relative density of the composites did not change considerably. Mechanical tests revealed that microhardness was reduced about 19% by the incorporation of carbon fibers, whereas the flexural strength improved significantly. However, the flexural strength diminished by adding carbon fibers above to critical value (5 vol%) due to residual thermal stresses, nonhomogeneous structure and graphitization of carbon fibers. It was found that the composite with 5 vol% Cf had the highest flexural strength (482 MPa), which was enhanced by 20% compared with the TiB2–SiC composite.

Effect of short carbon fiber content and water absorption on tensile and impact properties of PA6/PP blend based composites

AbstractPA6 absorbs moisture, restricting its use in humid applications. The first objective of this study is to process composite parts to be used in high humid applications using PA6 blend based matrix (PA6/PP/PP‐g‐MA) and SCF (3‐15 wt%) reinforcement. The second objective is to perform tensile and impact tests in both dry and wet conditions. The third objective is to carry out the in‐depth analysis of fractography of blends and composites. For blend, more than 50% reduction in water absorption was observed in comparison to pure PA6, indicating the need to blend with PP. The tensile strength of the composite with 15 wt% SCF was 55% and 133% higher than matrix blend in dry and wet conditions respectively indicating the need to reinforce the blend with SCF. Injection molded composites with 15 wt% SCF revealed the tensile strength of 54 MPa, 46 MPa and modulus of 5 GPa, 4 GPa in dry, wet state respectively. At higher SCF content, both SCF and PP are well dispersed in PA6 matrix but fiber pull out led to fracture of dry samples. Post water absorption, tensile fractured samples showed significant fiber pull out, indicating reduction in interfacial adhesion due to water absorption.

Evaluating the Effect of Carbon Black—A Short Carbon Fiber Hybrid Filler on the Electro-Activated Shape Memory Cyanate Ester/Epoxy Composites

An electro-activated type shape memory cyanate ester-epoxy (CE-EP) composites containing short carbon fiber (SCF) and carbon black (CB) were fabricated, where SCF linked among CB particles to make the superior conductivity network in compositions. In the compositions, the content of CB was fixed at 5 wt%, while the amount of SCF was ranged from 0 to 0.9 wt%. The synergistic effects of SCF and CB on the mechanical properties test, electrical properties, SEM, DMA and the electro-activated type shape memory experiment was reviewed. The outcomes showed that when the parts of SCF is less than 0.9%, the mechanical properties and storage modulus of required compositions expand with the content of the SCF growth. But, when the SCF content reaches 0.9 wt%, the flexural strength and storage modulus of the compositions decrease slightly. With the growth of SCF content, the glass transformation temperature increases from 89 °C to 103 °C and the resistivity of the composites decreases gradually. The resistivity of the composites is only 7.37 Ω/cm with 0.9 wt% of SCF. Further, the thermal response speed and shape convalescence rate of the compositions increase greatly with the growth of SCF content.

Effect of short carbon fiber content on SCFs/AZ31 composite microstructure and mechanical properties

The magnesium matrix composites containing various content of short carbon fibers reinforcement (SCFs/AZ31) were fabricated by ball milling and solid state synthesis. Morphologies of composite, distribution of SCFs, and interface of matrix and reinforcement were analyzed. The effect of SCFs content on the mechanical properties of the composite was studied. When the content of SCFs is less than 3%, SCFs uniformly distribute in the composite and promote dynamic recrystallization, the refining effect of grain is obvious, and meanwhile SCFs can play the effect of load transfer to the matrix. With the increase of SCFs content, the degree of aggregation increases, the grain size of composite increases and mechanical properties decrease. For mechanical performance, the strengthen effects was firstly enhanced and then deteriorated with increasing SCFs content. The main strengthening mechanisms of composite are grain refinement strengthening, thermal residual stress strengthening, and load transfer strengthening.

Influence of carbon fiber content on bio-tribological performances of high-density polyethylene

The present study aims to investigate the effect of short carbon fiber (SCFs) content on wear performance of high-density polyethylene (HDPE). SCFs reinforced composites with different weight fractions (5 wt%, 10 wt%, 15 wt% and 20 wt%) were fabricated by melt compounding and compression molding. To evaluate bio- tribological performance of the samples, three different loads (20 N, 40 N and 60 N) were applied to simulate body fluid (SBF) environment against stainless steel counterface. The scanning electron microscope was used to investigate the morphology of composite granules and worn surfaces of samples. Also, the hardness test was conducted for all samples. The results show that the hardness of high-density polyethylene increases significantly depending on the short carbon fiber content. 20 wt% SCFs reinforced composite exhibited the highest hardness, which is 34% improvement compared to the pure HDPE. However, the same trend was not observed for wear resistance of composites. Composites containing 10 wt% SCFs showed best wear performance in SBF fluid conditions.

The Evolution of Interfacial Microstructure and Fracture Behavior of Short Carbon Fiber Reinforced 2024 Al Composites at High Temperature

The short carbon fiber reinforced 2024 Al composites were fabricated through powder metallurgy. The effect of short carbon fiber content on the interfacial microstructure and fracture behavior of the composites at different temperatures were investigated. The results showed that the dislocation accumulation was formed in the aluminum matrix due to the thermal expansion mismatch between carbon fiber and aluminum matrix. With the testing temperature increasing, the size of interfacial product Al4C3 and precipitates Al2Cu became larger, and the segregation of Al2Cu was found coarsening around Al4C3. The addition of short carbon fiber improved the hardness and modulus of the aluminum matrix in the vicinity of the interface between carbon fiber and aluminum matrix. Compared to the matrix 2024 Al, the yield strength and ultimate tensile strength of the composites first increased and then decreased with increasing short carbon fiber content at room temperature 423 Kand 523 K. The fracture surface of the composites at room temperature was characterized by shear failure of fiber, while the interface debonding and fiber pulled-out became predominant fracture morphologies for the fracture surface at increased temperatures.

Effects of short carbon fiber content on microstructure and mechanical property of short carbon fiber reinforced Nb/Nb5Si3 composites

The short carbon fiber reinforced Nb/Nb5Si3 composites were innovatively fabricated by ball milling and spark plasma sintering. The effects of short carbon fiber contents (0.50 wt. %, 1.0 wt. %, 1.5 wt. % and 2.0 wt. %) on the microstructure and mechanical property of short carbon fiber reinforced Nb/Nb5Si3 the composites were investigated. The results show that the content of interfacial phase Nb4C3 increases with the increase of short carbon fiber content. Compared to the matrix Nb/Nb5Si3, the mechanical properties of the composites are improved significantly owing to the addition of short carbon fiber. It is found that the increase of short carbon fiber content contributes to the enhancement of Vickers hardness, ultimate tensile strength and fracture toughness of the composites. The fracture surfaces are characterized by interface debonding and fiber pull-out, which indicate that a medium bonding strength of the interface between fiber and matrix was obtained in this composite. The interface debonding and fiber pull-out behavior play the important role in the fracture process, which are the dominant toughening mechanisms of the short carbon fiber reinforced Nb/Nb5Si3 composites.

Thermomechanical and shape memory properties of SCF/SBS/LLDPE composites

A thermally triggered shape memory polymer composite was prepared by blending short carbon fiber (SCF) into a blend of poly(styrene-b-butadiene-b-styrene) triblock copolymer (SBS)/linear low density polyethylene (LLDPE) prior to curing. These composites have excellent processability compared with other thermosets. The dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) were investigated to assess the thermomechanical properties of the SCF/SBS/LLDPE composite. Scanning electron microscope (SEM) imaging of the samples was performed to show the distribution of the SCF in the composite. The study specifically focused on the effect of SCF on the shape memory behavior of the SCF/SBS/LLDPE composite. The results indicated that the large amount of SCF significantly improved the mechanical property of the polymer composites while not damaging the shape memory performance. The SCF/SBS/LLDPE composites exhibited excellent shape memory behavior when the SCF content was less than 15.0 wt%. Moreover, the shape fixity ratio and shape recovery time of the SCF/SBS/LLDPE composites increased with the SCF content.

Fabrication and properties of Cfiber/Si3N4 composite by vacuum hot-pressing sintering

Cfiber/Si3N4 composites were fabricated by vacuum hot-pressing at 1600°C under an applied pressure of 30MPa with α-Si3N4 powders, sintering additives and short carbon fibers. The microstructure, composition, mechanical and dielectric properties of Cfiber/Si3N4 were investigated. The SEM analysis results reveal that the short carbon fibers were uniformly distributed in the composites. When the short carbon fiber content of the composites increased from 1 to 5wt%, the flexural strength of the composites decreased from 291 to 119MPa and the density of the composites decreased from 3.10 to 2.38gcm−3. The dielectric constant varied from 5 to 135 at P-band. Microwave absorption ability of Cfiber/Si3N4 composites varied greatly over the frequency range 12.4–18GHz and the peak of dielectric constant was bound up with the content of short carbon fiber.

Experimental analysis and theoretical modeling of the mechanical behavior of short glass fiber and short carbon fiber reinforced polycarbonate hybrid composites

In this research, polycarbonate (PC) composites with short glass fiber (SGF) and short carbon fiber (SCF) hybrid fiber reinforcements were compounded by single screw extruder and specimens were prepared by injection molding machine. This article aims to investigate the mechanical properties of PC hybrid composites, by means of the experimental and the theoretical methods. The composites were subjected to tensile test. Experimental results showed the improvements in tensile strength and modulus by increasing the SCF content of the hybrid composite. The theoretical tensile strength was predicted based on Kelly–Tyson model and rule of hybrid mixture. Kelly–Tyson model showed to be a good approximation to predict the tensile strength of composite. When the SCF was replaced by milled carbon fiber (MCF) to form a PC/SGF/MCF hybrid system, poorer mechanical properties are reported due to the weaker interfacial adhesion between MCF and PC, as proven by the scanning electron microscopy. POLYM. COMPOS., 37:1238–1248, 2016. © 2014 Society of Plastics Engineers

Different Content of Short Carbon Fiber Influence on the Hardness of Thermo Plastic Resin Composite Material

Using screw injecting molding method to prepare the short fiber strengthening thermo plastic resin composite material, using short carbon fiber as strengthening material and polytene resin as matrix. Study different influence of carbon fiber content to the hardness of short fiber strengthening thermo plastic resin composite material. The result shows that the hardness of short carbon fiber strengthening thermo resin composite material increase as increasing the short carbon fiber content.