Carbon Fiber Reinforced Polyphenylene Sulfide Research Articles

Feasibility study of friction stir joining of aluminium with carbon fibre reinforced thermoplastic composite

During the last decades, environmental concerns and limited resources have set focus of research on lightweight, mechanically high-performing structures for the transportation industry, in order to reduce fuel consumptions and CO2 emissions. Friction Stir Joining (FSJ), as a variant of the Friction Stir Welding (FSW), is an innovative friction-based joining technique for metal-composite hybrid structures. Joining in the plasticized state below the melting temperature of the metal leads to a comparatively small heat-affected zone, so that only minor metallurgical changes occur. Additionally, only a short processing time and no additional weight in form of fasteners is needed. The main objective of this study is to evaluate the feasibility of metal-composite structures via FSJ, intending to enable a macro-mechanical interlocking bonding mechanism. Main focus was given to the integration of an aluminium nub inserted in a carbon fiber-reinforced polyphenylene sulfide (CF-PPS) sheet, to ensure sufficient plasticization of the aluminium part and no degradation in the polymer part. Residual stress arising from the friction stir joining process was also characterised using the Contour method. In this study, aluminium alloy 6082-T6 and CF-PPS composite sheets were used to produce long lap joints. Results have shown that the joints were created at almost constant peak temperature slightly above the melting temperature of the PPS but no physical-chemical changes were detected in the PPS. In addition, the influence of a PPS film as interlayer between the sheets was investigated in order to explore a method for preventing galvanic corrosion. Preliminary results indicate that it is not possible to integrate a metal nub to the CF-PPS without interrupting the PPS film. However, it is possible to create a nub within the PPS film.

Thermal decomposition study of carbon fiber-reinforced polyphenylene sulfide at high heating rates met under fire exposure

Thermal decomposition study of carbon fiber-reinforced polyphenylene sulfide at high heating rates met under fire exposure

Additive Manufacturing of Composite Polymers: Thermomechanical FEA and Experimental Study.

This study presents a comprehensive approach for simulating the additive manufacturing process of semi-crystalline composite polymers using Fused Deposition Modeling (FDM). By combining thermomechanical Finite Element Analysis (FEA) with experimental validation, our main objective is to comprehend and model the complex behaviors of 50 wt.% carbon fiber-reinforced Polyphenylene Sulfide (CF PPS) during FDM printing. The simulations of the FDM process encompass various theoretical aspects, including heat transfer, orthotropic thermal properties, thermal dissipation mechanisms, polymer crystallization, anisotropic viscoelasticity, and material shrinkage. We utilize Abaqus user subroutines such as UMATHT for thermal orthotropic constitutive behavior, UEPACTIVATIONVOL for progressive activation of elements, and ORIENT for material orientation. Mechanical behavior is characterized using a Maxwell model for viscoelastic materials, incorporating a dual non-isothermal crystallization kinetics model within the UMAT subroutine. Our approach is validated by comparing nodal temperature distributions obtained from both the Abaqus built-in AM Modeler and our user subroutines, showing close agreement and demonstrating the effectiveness of our simulation methods. Experimental verification further confirms the accuracy of our simulation techniques. The mechanical analysis investigates residual stresses and distortions, with particular emphasis on the critical transverse in-plane stress component. This study offers valuable insights into accurately simulating thermomechanical behaviors in additive manufacturing of composite polymers.

Carbon Fiber Polymer Reinforced 3D Printed Composites for Centrifugal Pump Impeller Manufacturing

Centrifugal pumps are used extensively in various everyday applications. The occurrence of corrosion phenomena during operation often leads to the failure of a pump’s operating components, such as the impeller. The present research study examines the utilization of composite materials for fabricating centrifugal pump components using additive manufacturing as an effort to fabricate corrosion resistant parts. To achieve the latter two nanocomposite materials, carbon fiber reinforced polyamide and carbon fiber reinforced polyphenylene sulfide were compared with two metal alloys, cast iron and brass, which are currently used in pump impeller manufacturing. The mechanical properties of the materials are extracted by performing a series of experiments, such as uniaxial tensile tests, nanoindentation and scanning electron microscope (SEM) examination of the specimen’s fracture area. Then, computational fluid dynamics (CFD) analysis is performed using various impeller designs to determine the fluid pressure exerted on the impeller’s geometry during its operation. Finally, the maximum power rating of an impeller that can be made from such composites will be determined using a static finite element model (FEM). The FEM static model is developed by integrating the data collected from the experiments with the results obtained from the CFD analysis. The current research work shows that nanocomposites can potentially be used for developing impellers with rated power of up to 9.41 kW.

Fatigue resistance of carbon fiber/polyphenylene sulfide composites engineered for automotive use

AbstractThis study comprehensively investigates a carbon fiber‐reinforced polyphenylene sulfide (CF/PPS) composite through tensile, fatigue, interlaminar shear strength (ILSS), dynamic mechanical tests (DMA), and also fractographic analysis. Prepared via hot compression molding, the CF/PPS composites exhibit a consistent quality. Tensile tests show an elastic modulus of 37.2 ± 0.2 GPa and an average tensile strength of 800 ± 73 MPa. Fatigue tests demonstrate infinite life at 1 million cycles, achieved at 80% of the maximum stress level. Fractographic analyses unveil directly attributable fiber failures (DAFFs), affirming a robust fiber/matrix interface. DMA shows a glass transition temperature of 86°C, showcasing the composite's structural integrity across varied temperatures. With an ILSS of 68.8 ± 3.5 MPa, the composite displays excellent fiber‐matrix adhesion. The results highlight the suitability of the CF/PPS composite for high‐strength and lightweight applications in the automotive sector, offering valuable insights for material selection, design, and production processes. Thus, contributing to the production of durable and efficient automotive components among the challenges of modern and safe transportation.Highlights Comprehensive study on CF/PPS composites. Varied mechanical assessments: tensile, fatigue, ILSS, DMA. Uniform preparation via hot compression molding. Detailed fractography reveals a strong fiber/matrix interface. Suitability for high‐strength and lightweight automotive applications.

The Influence of Thermal Parameters on the Self-Nucleation Behavior of Polyphenylene Sulfide (PPS) during Secondary Thermoforming.

During the secondary thermoforming of carbon fiber-reinforced polyphenylene sulfide (CF/PPS) composites, a vital material for the aerospace field, varied thermal parameters profoundly influence the crystallization behavior of the PPS matrix. Notably, PPS exhibits a distinctive self-nucleation (SN) behavior during repeated thermal cycles. This behavior not only affects its crystallization but also impacts the processing and mechanical properties of PPS and CF/PPS composites. In this article, the effects of various parameters on the SN and non-isothermal crystallization behavior of PPS during two thermal cycles were systematically investigated by differential scanning calorimetry. It was found that the SN behavior was not affected by the cooling rate in the second thermal cycle. Furthermore, the lamellar annealing resulting from the heating process in both thermal cycles affected the temperature range for forming the special SN domain, because of the refined lamellar structure, and expelled various defects. Finally, this study indicated that to control the strong melt memory effect in the first thermal cycle, both the heating rate and processing melt temperature need to be controlled simultaneously. This work reveals that through collaborative control of these parameters, the crystalline morphology, crystallization temperature and crystallization rate in two thermal cycles are controlled. Furthermore, it presents a new perspective for controlling the crystallization behavior of the thermoplastic composite matrix during the secondary thermoforming process.

Processing and characterization of high-performance thermoplastic composites manufactured by laser-assisted automated fiber placement in-situ consolidation and hot-press

Due to the short dwell time of processing temperature and pressure, the quality of the composite manufactured by AFP was not equal to the traditional processing method like autoclave or hot-press. Deeply understanding the mechanism of differences was conducive to improving the performance of the composite manufactured by AFP. In this study, the properties of high-performance carbon fiber reinforced polyphenylene sulfide (CF/PPS) thermoplastic composites manufactured by laser-assisted automated fiber placement (LAFP) in-situ consolidation and hot-press was characterized and compared. The temperature history of LAFP in situ consolidation indicated that the heating and cooling process occurred during a few seconds. And the crystallinity was only 21.6% for the laminate from LATP, while the void content was 2.75%. Due to the low crystallinity, high void content and low interlaminar bonding, the ILSS of the laminate from LAFP in situ consolidation was 34.9% lower than that of hot-press. However, the mode Ⅰ fracture toughness was 103.7% higher than hot-press.

Optimizing the buckling resistance of injection molding composite plates by manipulating gate locations

In contrast to continuous-fiber-reinforced polymer (cFRP), the random distribution of fibers in short-fiber-reinforced polymer (sFRP), which depends on the manufacturing process, has a significant impact on the mechanical properties of sFRP components. In this study, an automatic joint injection-buckling analysis framework was developed that can simulate the injection process and predict the mechanical performance in sequence. This automatic analysis framework can be directly utilized to optimize the manufacturing process to improve mechanical properties. Based on this method, it is demonstrated that an sFRP plate (consisting of carbon fiber-reinforced polyphenylene sulfide) has better buckling resistance than an aluminum alloy plate with the same design weight. The buckling resistance can be further improved by manipulating the gate location in the injection molds. The optimization scheme was verified using the conventional analysis framework. Moreover, the optimization method was improved by utilizing a tensor-similarity-based algorithm, which can substantially decrease the time required to locate the optimal solution.

Refill friction stir spot welding of thermoplastic composites: Case study on Carbon-fiber-reinforced polyphenylene sulfide

Refill Friction Stir Spot Welding (refill FSSW) is an innovative solid-state welding technique that has been successfully applied to various combinations of metallic materials. The objective of the present study is to investigate the feasibility of refill FSSW for polymer–polymer structures, with a specific emphasis on carbon-fiber-reinforced polyphenylene sulfide (CF-PPS). The influence of the key joining parameters, i.e. force, plunge depth, rotational speed, and tool diameter, has been analyzed in terms of the resulting joint microstructure, mechanical strength, and failure mechanisms. The lap shear tests revealed two primary failure modes: interfacial shear failure and nugget pull-out. Fracture surfaces exhibited broken fibers. The depth of the joint was found to play a crucial role in determining the failure mode, with interfacial shear failure resulting in higher lap shear strength. Thermal analyses conducted on the produced joints showed no evidence of thermal degradation, which aligns with the temperature measurements during the process, as they remained below the melting temperature of CF-PPS.

Effects of thermal process conditions on crystallinity and mechanical properties in material extrusion additive manufacturing of discontinuous carbon fibre reinforced polyphenylene sulphide composites

This study investigates the thermal behaviour of discontinuous carbon fibre reinforced polyphenylene sulphide (CF/PPS), additively manufactured by material extrusion, with a focus on the effects of thermal process conditions on the degree of crystallinity, oxidation crosslinking and mechanical properties of CF/PPS from filament fabrication, material extrusion to annealing treatment. The screw extrusion parameters are optimised by performing a thermal analysis of the fabricated filaments. The effect of crosslinking reactions on the crystallinity process in determining the mechanical properties of the printed samples is illustrated by investigating the influence of the printing conditions. Furthermore, the effect of annealing treatment on the semi-crystalline polyphenylene sulphide (PPS) is studied by measuring the degree of crystallinity and viscoelasticity behaviours. Results demonstrate that the flexural properties of the printed CF/PPS composites at elevated processing temperatures are determined by the oxidation crosslinking between PPS chains. These enhance the crystallisation process of semi-crystalline polymers by acting as the nucleating agent first but negatively affect the mechanical properties at higher temperatures because of the detrimental effects of the polymer inter-chain bonding. The maximum flexural strength of printed CF/PPS reached 164.65 MPa when processing at an extrusion temperature of 280°C, a printing temperature of 320°C, and an annealing temperature of 130°C for 6 h. By adjusting the thermal treatment conditions, the degree of the crystallinity and the mechanical properties of the printed CF/PPS composites can be designed, controlled and tailored.

Enhancement of interfacial properties of carbon fiber reinforced polyphenylene sulfide resin by sulfur treatment

AbstractThe properties of carbon fiber (CF) reinforced thermoplastic resin composites depend on the physical and chemical interaction between the fibers and the resins. However, surface oxidation is not always necessary. In this study, the interaction between CF and Polyphenylene sulfide (PPS) is enhanced by using an emulsion of reactive sulfur to treat the CF surface. The interlaminar shear strength (ILSS) of CF/PPS composites is experimentally investigated and found to be up to 79.7 MPa, an increase of 36.1% compared to the untreated CF. The enhancement mechanism of the modification method established is inferred. Scanning electron microscope (SEM) and X‐ray photoelectron spectroscopy (XPS) results showed that sulfur etching on the surface of CF generated new functional groups, which improved the interfacial effect, and tightened the bond between CF and PPS. This indicates that sulfur treatment along with sizing must be a simpler method than surface oxidation to promote the interfacial bonding between CF and PPS.

Applicability assessment of thermoset coating onto additively manufactured thermoplastic composite molds

Coatings can significantly enhance the surface characteristics of printed molds however, there is no guideline to assess the coating applicability for additively manufactured fiber-reinforced thermoplastic molds. Therefore, the applicability of a thermoset polymer surface coating onto additively manufactured carbon fiber-reinforced Polyphenylene Sulfide (CF-PPS) composite mold was investigated. The coating application temperature should not be higher than the maximum operable temperature of the substrate. Therefore, Dynamic Mechanical Analysis (DMA) of the printed CF-PPS was performed to characterize the dependence of the elastic modulus on temperature as well as to verify the thermal stability of the printed molds at the coating processing temperature. The cure kinetics of the coating material was characterized to guide the design of processing conditions to achieve a complete cure of the thermoset resin. The composite mold needs to withstand multiple thermal cycles for the part manufacturing process. Thermal degradation of the coating was assessed for multiple thermal cycles utilizing Thermogravimetric Analysis (TGA) and the results did not show significant degradation. To provide insights into the coefficient of thermal expansion (CTE) mismatch between the coating and the printed CF-PPS, the CTE was characterized for both material systems. Additionally, the coating adhesion was characterized via pull-off tests after multiple thermal cycles and the results revealed no significant change in the pull-off strength after ten cycles. Finally, the coating was demonstrated on a mold printed with CF-PPS which was subjected to multiple autoclave composite part manufacturing cycles. The durability of the coating and the geometrical deviation of the mold were investigated throughout the manufacturing cycles.

A water-soluble PAAs sizing agent for enhancing interfacial adhesion of carbon fiber reinforced polyphenylene sulfide composites (CF/PPS)

Due to low activity and poor wettability of carbon fiber (CF), the interaction between CF and polyphenylene sulfide (PPS) matrix is weak, which decreases the mechanical properties of CF reinforced PPS （CF/PPS） composites. In this article, the interfacial adhesion of CF/PPS composites was strengthened by using a water-soluble poly (amic acid) ammonium salt (PAAs) as sizing agent. This PAAs-based sizing agent had good compatibility with PPS and formed hydrogen bonds with CF activated by Meldrum’s acid. Significantly, the PAAs sizing agent can be soluble in water (up to 20 wt % high solid content) without organic solvents and surfactants, which shows huge potential in industrial applications. Experimental results demonstrated that the interlaminar shear strength (ILSS), flexural strengths, and moduli of modified CF/PPS composites increased by 19.5%, 24.9%, and 10.1%, respectively. According to the SEM images on fractured surfaces of composites, fiber and PPS resin were tightly packed, and the failure mechanism was interface deformation or resin breakage.

3D printing of continuous carbon fiber reinforced polyphenylene sulfide: Exploring printability and importance of fiber volume fraction

Additive manufacturing (AM) of thermoplastic polymer composites is rapidly advancing in the aerospace industry. Here, fused deposition modeling (FDM) of continuous carbon fiber reinforced polyphenylene sulfide (CCF/PPS) was explored and involved experimental filaments with nominal fiber volume fractions (V f ) ranging from 30% to 50%. The printability was evaluated using a design of experiments to quantify the contribution of process parameters to the printed filament quality, which considered microstructure, surface texture and both the thermal and mechanical properties. Results showed that nozzle height, nozzle temperature, printing speed, and flow rate were most influential parameters to the printing process; the relative importance of the printing parameters depended on the V f . The filament with 50% V f was successfully printed despite its high fiber volume fraction and achieved an average ultimate tensile strength of 1930 ± 150 MPa, which sets a new benchmark in strength for composites developed by AM. Nevertheless, there are challenges to achieving that strength in printed components. • Fused filament fabrication of an experimental continuous carbon fiber reinforced polyphenylene sulfide. • High volume fraction of fibers achieves tensile strength approaching 2GPa. • Parametric dependence in printed material quality depends on fiber volume fraction.

Effect of the cooling rate on the fracture toughness of carbon fiber reinforced thermoplastic composites

Carbon fiber (CF) reinforced thermoplastic composites have great potential in the aerospace industry. However, defects and delamination restrict the application of the composites. This study investigated the effect of cooling rate on the crystallization and inter-laminar fracture toughness of CF reinforced polyphenylene sulfide (CF/PPS) composites. Differential scanning calorimetry (DSC) results showed that the crystallinity of the composites decreased from 49.6% to 27.1% when the cooling rate increased from 2°C/min to 1000°C/min. Meanwhile, mode I and mode II fracture toughness, as measured by the double cantilever beam (DCB) and end-notched flexure (ENF) tests, increased by 486% and 52%, respectively. The fracture morphology of the composites after DCB tests showed that when the cooling rate was 2, 30, and 300°C/min, the crack propagation occurred inside the resin, which was a typical cohesive failure. Moreover, when the cooling rate was 1000°C/min, the crack propagation belonged to the combination of cohesive and adhesive failure, indicating that a high cooling rate was conducive to improving the fracture toughness. It also turned out that the contribution of the matrix deformation dominated the fracture toughness.

The Micro–Macro Interlaminar Properties of Continuous Carbon Fiber-Reinforced Polyphenylene Sulfide Laminates Made by Thermocompression to Simulate the Consolidation Process in FDM

Three-dimensional (3D) printing of continuous fiber-reinforced composites has been developed in recent decades as an alternative means to handle complex structures with excellent design flexibility and without mold forming. Although 3D printing has been increasingly used in the manufacturing industry, there is still room for the development of theories about how the process parameters affect microstructural properties to meet the mechanical requirements of the printed parts. In this paper, we investigated continuous carbon fiber-reinforced polyphenylene sulfide (CCF/PPS) as feedstock for fused deposition modeling (FDM) simulated by thermocompression. This study revealed that the samples manufactured using a layer-by-layer process have a high tensile strength up to 2041.29 MPa, which is improved by 68.8% compared with those prepared by the once-stacked method. Moreover, the mechanical–microstructure characterization relationships indicated that the compactness of the laminates is higher when the stacked CCF/PPS are separated, which can be explained based on both the void formation and the nanoindentation results. These reinforcements confirm the potential of remodeling the layer-up methods for the development of high-performance carbon fiber-reinforced thermoplastics. This study is of great significance to the improvement of the FDM process and opens broad prospects for the aerospace industry and continuous fiber-reinforced polymer matrix materials.

Effects of processing parameters on the performance of carbon fiber reinforced polyphenylene sulfide laminates manufactured by laser-assisted automated fiber placement

In situ consolidation of thermoplastic composites can be realized through laser-assisted automated fiber placement (AFP) technology, and the properties of composites were significant affected by the process parameters. In this work, the effects of process parameters on the properties of continuous carbon fiber–reinforced polyphenylene sulfide (CF/PPS) composites manufactured by laser-assisted AFP were investigated. Four-plies CF/PPS prepreg was laid under the combination of different process parameters and the morphology, void content, crystallinity, and inter-laminar shear strength (ILSS) of the composites were characterized. It turned out that the resin distribution on the surface of the composites could be significantly improved by increasing the laser temperature and compaction pressure. The highest crystallinity of the composites reached 46% at tool temperature of 120°C while the value was only 18% when the tool temperature was 40°C. Meanwhile, with the increasing compaction force ranging of 500–2000 N, the void content of the composites decreased obviously. The ILSS was evaluated through double notch tensile shear test. The results indicated that the mechanical properties of the composites were dominated by void content rather than crystallinity.

Enhancing part demolding characteristics of additively manufactured fiber-reinforced polymer composite tools via surface coating

The influence of a surface coating on the demolding characteristics of an additively manufactured fiber-reinforced polymer composite tool was investigated. An experimental setup was developed to measure the reaction force developed as a part was demolded from an additively manufactured tool. The tool used in the demolding experiments consisted of a cylindrical geometry and was additively manufactured with 50% by weight of carbon fiber reinforced polyphenylene sulfide (PPS). A commercial thermoset-based liquid coating was applied, and a composite laminate was laid on the surface of the tool and cured in an autoclave process. The force was recorded as a function of the displacement during the part demolding process of both the coated and non-coated tools. The demolding test results showed that the initial force required to demold the part and the kinetic friction coefficient between the tool and the part decreased substantially with the application of the coating. Further, the stick-slip behavior developed during the demolding process of the part was significantly reduced with the coating. Stereoscopic images of the tool surface revealed that the coating filled voids initially present at the surface of the tool, thereby producing a smoother and more homogenous surface texture than the non-coated tool. Although a significant reduction in the part demolding force was obtained with the application of the coating, the coating started to chip off upon multiple part manufacturing cycles which compromised the part demolding characteristics of the coating.

Effect of hygrothermal environment on properties of induction welding joint of carbon fiber reinforced polyphenylene sulfide laminate

The carbon fiber reinforced polyphenylene sulfide (CF/PPS) composite laminate was taken as the research object, and the induction welding method was used to weld the CF/PPS laminate. It was focused on the effect of hygrothermal on the welded joint performance of the CF/PPS laminate. The experimental results show that the PPS resin does not undergo chemical changes before and after moisture absorption. At room temperature, the shear strengths of the welded joints gradually decrease with the increase of moisture absorption time, and compared with the dry welded joints, they are reduced by 15%, 18%, 23%, 32%, and 38%, respectively. The wet stress increases at the interface of the stainless steel mesh, resin matrix and carbon fiber, which weakens the bonding performance of the welded joint interface, and affects the failure mode of the welded joint. Under the environment of 120℃, the shear strength values of the welded joints with different moisture absorption times decrease by 12%, 15%, 22%, 37% and 44%, respectively. High temperature and high humidity make the thermal stress and wet stress at the interface of the stainless steel mesh, resin matrix and carbon fiber greater, which aggravates the damage of interface bonding performance. Interface debonding is the main failure form of the welded joints.

Improve durability and surface quality of additively manufactured molds using carbon fiber prepreg

AbstractHybrid tooling is an emerging concept introduced in the aerospace industries to reduce weight and cost of traditional tools. A hybrid tool features a skin, which provides desired surface quality, durability, and a low‐density substrate to reduce the weight of the mold. The big area additive manufacturing (BAAM) technology permits rapid production of thermoplastic polymer intensive large‐scale structures. The present study features a carbon fiber reinforced polyphenylene sulfide (CF‐PPS) substrate fabricated using Oak Ridge National Laboratory's BAAM system. Carbon fiber‐bismaleimide (CF‐BMI) prepreg skin was then bonded to the BAAM tool through high‐pressure autoclave molding. Process optimization was conducted to improve the bonding between CF‐PPS and CF‐BMI (transverse tensile strength increased from 0.54 to 4.8 MPa). Durability of the mold was demonstrated from fabricating seven (7) carbon fiber‐Huntsman epoxy hand lay‐up parts utilizing the mold.