Carbon Fiber-reinforced Polyetheretherketone Research Articles

Development and Evaluation of an MRI Artifact-Free Aneurysm Clip.

The digital subtraction angiography is still the gold standard in the follow-up after aneurysm surgery, although it remains a repeating invasive technique with accumulating X-ray exposure. An alternative magnetic resonance angiography has the disadvantage of metal-related artifacts. A metal-free aneurysm clip could overcome this problem. Recent advances in manufacturing technologies of fiber-reinforced plastics might allow developing a prototype of a metal-free clip. The prototype was formed out of carbon fiber-reinforced polyetheretherketone (CF-PEEK) in accordance with the standard clip design. In vivo and in vitro studies were performed to analyze the central nervous system biocompatibility. The prototype was tested in a phantom in a 3 T MRI scanner and microtomography scanner. For in vivo assessment, the left renal artery of rats was either ligated with a suture, clipped with a regular titanium clip or with the CF-PEEK prototype clip. The animals underwent standard MRI sequences and magnetic resonance angiography and assessment by a blinded neuroradiologist. Phantom studies showed no signs of artifacts. The prototype showed a reliable clamping and reopening after clip application, although the clamping force was reduced. In vivo studies showed a successful occlusion of the renal artery in all cases in the magnetic resonance angiography. Clip artifacts were statistically significant reduced in the prototype group (P < .01). CF-PEEK showed no signs of impaired biocompatibility compared with the titanium samples in vitro and in vivo. Former attempts of metal-free aneurysm clips did not meet the criteria of the standard clip design. In this study, the practicability of this new CF-PEEK artifact-free aneurysm clip has been proven. The further fabrication developments should overcome the problem of a reduced clamping force in the future. After clinical approval, it will improve the magnetic resonance image quality and might help to reduce the amount of digital subtraction angiography in the follow-up.

Advancing spacecraft demisability through a novel composite bolt joint system: a step toward sustainable and safe space environments

AbstractFrom the recent awareness of the booming number of space debris and their derived worldwide re-entry event threat originating from the use of high survivability components, complementary mitigation measures must be taken for future orbital elements. In this direction, the implementation of a design for demise at an early stage of spacecraft conception allows a progressive and effective solution. As part of a collaborative effort launched by École Polytechnique Fédérale de Lausanne and the European Space Agency, we focus on the evaluation of polymer composite bolts as the main structural satellite panel fastening systems to improve the overall spacecraft demisability during its destructive re-entry into the atmosphere as compared to baseline critical systems, while maintaining equivalent mission-relevant properties. Two carbon fiber-reinforced polyetheretherketone (PEEK) designs were compared to a stainless steel baseline in terms of static properties at room temperature, dynamic properties over a temperature range, as well as demise capability by static re-entry simulation testing. The results led us to identify a promising short CF/PEEK composite bolt design.

Effect of fabrication process on the microstructure and mechanical performance of carbon fiber reinforced PEEK composites via selective laser sintering

Carbon fiber reinforced PEEK (CF/PEEK) composites via selective laser sintering (SLS) are highly promising technologies for the fabrication of polymer-based components with excellent mechanical behavior. In order to further enhance the performance of SLS-CF/PEEK composites, the mixed CF/PEEK powders are designed and CF/PEEK composites are fabricated via SLS under different fabrication process parameters. The effect of laser power, layer thickness, paving speed, fiber weight fraction, and fiber length on the microstructure and mechanical performance along the powder spreading direction is investigated for SLS-CF/PEEK. The results show that the failure strength of 117 MPa is achieved while the layer thickness of 0.08 mm is adopted. Moreover, the fiber weight fraction of 15% is proven to be suited during the fabrication of SLS-CF/PEEK. The maximum failure strength is better than the results of SLS-CF/PEEK with the fiber weight fraction of 10%, and the average elastic modulus reaches 8400 MPa, which is the best result among those published works. In addition, it is found that the correlation between the failure strength and paving speed is non-monotonic, and the higher strength is obtained when the longer carbon fiber is used. Different from the distinct trends in failure strength, the sensitivity of modulus is much less obvious for SLS-CF/PEEK. This work provides guidance for the printing of high-strength CF/PEEK composites.

The Influence of Titanium-coated Poryetheretherketone Cages in Fusion Status after Posterior Lumbar Interbody Fusion with Cortical Bone Trajectory Screw Fixation

Posterior lumbar interbody fusion (PLIF) with cortical bone trajectory (CBT) screw fixation (CBT-PLIF) shows potential for reducing adjacent segmental disease. Previously, our investigations revealed a relatively lower fusion rate with the use of carbon fiber-reinforced polyetheretherketone (CP) cages in CBT-PLIF compared with traditional pedicle screw fixation (PS-PLIF) using CP cages. This study aims to evaluate whether the implementation of titanium-coated polyetheretherketone (TP) cages can enhance fusion outcomes in CBT-PLIF. A retrospective analysis was conducted on 68 consecutive patients who underwent CBT-PLIF with TP cages (TP group) and 89 patients who underwent CBT-PLIF with CP cages (CP group). Fusion status was assessed using computed tomography at 1 year postoperatively and dynamic plain radiographs at 2 years postoperatively. No statistically significant differences in fusion rates were observed at 1 and 2 years postoperatively between the TP group (86.8% and 89.7%, respectively) and the CP group (77.5% and 88.8%, respectively). Notably, the CP group exhibited a significant improvement in fusion rate from 1 to 2 years postoperatively (P= 0.002), while no significant improvement was observed in the TP group. Examination of temporal changes in fusion rates reveals that only the TP group achieved a peak fusion rate 1 year postoperatively. This implies that TP cages may enhance the fusion process even after CBT-PLIF. Nevertheless, the definitive efficacy of TP cages for CBT-PLIF remains uncertain in the context of overall fusion rates.

Quantification of MRI Artifacts in Carbon Fiber Reinforced Polyetheretherketone Thoracolumbar Pedicle Screw Constructs prior to Spinal Stereotactic Radiosurgery

Carbon fiber reinforced polyetheretherketone (CFRP) is a nonmetallic material that is a subject of growing interest in the field of spinal instrumentation manufacturing. The radiolucency and low magnetic susceptibility of CFRP has potential to create less interference with diagnostic imaging compared with titanium implants. However, an objective comparison of the image artifact produced by titanium and CFRP implants has not been described. Spinal oncology, particularly after resection of spinal tumors and at the time of spinal stereotactic radiosurgery planning, relies heavily on imaging interpretation for evaluating resection, adjuvant treatment planning, and surveillance. We present a study comparing measurements of postoperative magnetic resonance imaging artifacts between titanium and CFRP pedicle screw constructs in the setting of separation surgery for metastatic disease. The diameter of the signal drop around the screws (pedicle screw artifact) and the diameter of the spinal canal free from artifacts (canal visualization) were measured in consecutive patients who had spinal instrumentation followed by spinal stereotactic radiosurgery in the June 2019 to May 2022 timeframe. The spinal cord presented a shift at the screw level in sagittal images which was also measured (Sagittal Distortion, SagD). Fifty patients, corresponding to 356 screws and 183 vertebral levels, were evaluated overall. CFRP produced less artifacts in all the 3 parameters compared with titanium: mean pedicle screw artifact (CFRP = 5.8 mm, Ti = 13.2 mm), canal visualization (CFRP = 19.2 mm, Ti = 15.5 mm), and SagD (CFRP = .5 mm, Ti = 1.9 mm), all P < .001. In practice, these findings translate into better-quality magnetic resonance imaging. The initial perceived advantages are easier evaluation of postoperative imaging, facilitating radiation treatment planning, recurrence detection, and avoidance in repeating a suboptimal computed tomography myelogram. Further clinical studies analyzing long-term outcomes of patients treated with CFRP implants are necessary.

Clinical Outcome of Carbon Fiber Reinforced Polyetheretherketone Plates in Patients with Proximal Humeral Fracture: One-Year Follow-Up.

Proximal humerus fractures are seen frequently, particularly in older patients. The development of new osteosynthesis materials is being driven by the high complication rates following surgical treatment of proximal humerus fractures. Plate osteosyntheses made of steel, titanium and, for several years now, carbon fiber-reinforced polyetheretherketone (CFR-PEEK) are used most frequently. A prospective, randomized study was conducted in order to evaluate whether there are differences in the functional postoperative outcome when comparing CFR-PEEK and titanium implants for surgical treatment of proximal humerus fractures. The primary outcome of shoulder functionality 1 year after surgery was measured with the DASH score, the Oxford Shoulder Score, and the Simple Shoulder Test. Bony consolidation of the respective fracture was confirmed in all the patients included in the study within the scope of postoperative follow-up care. No significant differences in the DASH score, Oxford Shoulder Score, or Simple Shoulder Test were observed 1 year post-operatively when comparing the implant materials CFR-PEEK and titanium. There are no differences in terms of the functional outcome between CFR-PEEK plates and titanium implants 1 year after surgery. Studies on the long-term outcomes using CFR-PEEK plates in osteoporotic bone should be the subject of further research.

Thermal-field analytical modeling of machined surface layer in high-speed-dry milling UD-CF/PEEK considering thermal anisotropy and nonlinear thermal conductivity

The high-speed-dry (HSD) machining is now recognized as a strong potential dry-cutting technique to tackle the rapidly growing productivity demand of carbon-fiber-reinforced-polyetheretherketone (CF/PEEK). The thermal-field is an essential breakthrough for eliminating the severe thermal effect of cutting temperature beyond CF/PEEK glass transition temperature Tg. However, the anisotropy and temperature-sensitive thermal conductivity of CF/PEEK lead to great challenges in thermal analytical modeling. Addressing this issue, a novel thermal-field analytical model that incorporates fiber orientation-dominated thermal anisotropy is developed to investigate the thermal field of machined surface layer for unidirectional (UD) CF/PEEK HSD milling, where the nonlinear thermal conductivity of CF/PEEK are imported into this model. With experiment verification, the thermal-field model can forecast the spatio-temporal distribution of workpiece temperature. Then, the thermal mechanisms of fiber orientations and milling parameters are clarified to restrict workpiece temperature within the Tg for limited thermal damage and reveal the feasibility essence of CF/PEEK HSD milling.

Clinical and radiological outcome after arthroscopic rotator cuff repair using PEEK-CF anchors

PurposeThe goal of this study was to evaluate the clinical and radiological outcome after arthroscopic rotator cuff repair using new carbonfiber reinforced polyetheretherketone (CF-PEEK) suture anchors. MethodsOne hundred (n=100) patients with rotator cuff tears were enrolled at seven French hospitals between July 2019 and June 2020. Pain levels, Constant score and Subjective Shoulder Value (SSV) were taken preoperatively and 6months postoperatively. Ultrasonography (US) was performed at 6months postoperatively to evaluate tendon healing using the Sugaya classification. Statistical analysis was done with the Student t-test with 95% confidence intervals. ResultsOne hundred patients of the 100 patients were followed at 6months. The mean SSV and Constant score improved from 40.1% preoperatively to 78% at 6months (p<0.0001) and from 43 points preoperatively to 65 points at 6months (p<0.0001), respectively. The mean level of pain, as measured with the visual analogue scale, decreased from 5.9 to 1.6 (p<0.001). There were no postoperative complications that resulted in revision surgery. ConclusionThe study showed good results at 6months follow-up using carbonfiber reinforced PEEK anchors with improved Constant and SSV scores as well as a high ultrasonographic tendon healing rate, making PEEK-CF anchors safe to use, comparable to commonly used anchors. Level of evidenceIV.

Cycle deformation behavior of 3D‐printed CF/PEEK honeycomb metamaterials with zero Poisson's ratios

AbstractTo realize the one‐dimensional deformation of morphing wings, zero Poisson's ratio (ZPR) honeycomb metamaterials have become a popular research topic due to their lightweight, low in‐plane modulus, and high out‐of‐plane strength. A ZPR honeycomb metamaterial is designed and prepared from short‐cut carbon fiber‐reinforced polyetheretherketone (CF/PEEK) by a 3D printer. The mechanical properties of ZPR honeycomb metamaterials were tested to determine their tensile and bending stiffness. The results show that the metamaterial can achieve 62.3% ± 3.3% in‐plane elastic deformation after optimized structure design. At the same time, metamaterial has a certain bending resistance to keep the airfoil from normal buckling deformation. Moreover, a new test method for evaluating the cycle deformation behavior of flexible morphing wings is proposed. The high‐speed cyclic tension‐compression test showed that H22‐t0.6‐CT has the best stability, which may be related to its lower porosity (2.15% ± 0.12%). These results indicate that ZPR honeycomb metamaterials have great application prospects in the field of morphing wings.Highlights The printed CF/PEEK wire is treated as a transversely isotropic material. ZPR honeycomb metamaterial allows for more than 50% in‐plane deformation. A new test method to evaluate the cyclic deformation behavior.

Correct positioning of the calcar screw leads to superior results in proximal humerus fractures treated with carbon-fibre-reinforced polyetheretherketone plate osteosynthesis with polyaxial locking screws

BackgroundPlate osteosynthesis with implants made of carbon-fibre-reinforced polyetheretherketone (CFR-PEEK) has recently been introduced for the treatment of fractures of the proximal humerus (PHFs). The advantages of the CFR-PEEK plate are considered to be its radiolucency, its favourable modulus of elasticity, and the polyaxial placement of the screws with high variability of the angle. The primary aim of this study is to investigate the influence of calcar screw positioning on the complication and revision rates after CFR-PEEK plating of PHFs. The secondary aim is to assess its influence on functional outcome.Material and methodsPatients were identified retrospectively. Minimum follow-up was 12 months. The cohort was divided into two groups depending on the distance of the calcar screw to the calcar (group I: < 12 mm, group II: ≥ 12 mm). The range of motion (ROM), Subjective Shoulder Value Score (SSV) and Constant–Murley Score (CS) were analysed at follow-up examination. Subjective complaints, complications (e.g. humeral head necrosis, varus dislocation) and the revision rate were evaluated.Results51 patients (33 female, 18 male) with an average age of 68.6 years were included after a period of 26.6 months (group I: 32 patients, group II: 19 patients). Apart from the gender distribution, no significant differences were seen in the patient characteristics. The outcome scores showed significantly better clinical results in group I: SSV 83.4 vs 71.2, p = 0.007; CS 79.1 vs 67.8, p = 0.013. Complications were seen less frequently in group I (18.8 % vs 47.4 %, p = 0.030).ConclusionThis study shows that the positioning of the calcar screw is relevant for CFR-PEEK plate osteosynthesis in PHFs with a good reduction of the fracture. Optimal positioning of the calcar screw close to the calcar (< 12 mm) is associated with a lower rate of complications, resulting in significantly superior functional outcomes.Level of evidence: III, retrospective cohort study

Prediction of milled surface characteristics of carbon fiber-reinforced polyetheretherketone using an optimized machine learning model by gazelle optimizer

Motivated by the nonlinear behavior of composite materials under different machining operations, this work aims at developing an optimized artificial intelligence model to predict milled surface characteristics of carbon fiber-reinforced polyetheretherketone (CFRPEEK). The milling operations were carried out under high-speed dry-cutting conditions. The developed model was employed to predict fractal dimension and surface roughness as functions of cutting speed, cutting width, feed per tooth, and orientation of fibers. The model is composed of an adaptive network-based fuzzy inference system (ANFIS) optimized by a gazelle optimizer (GO). The performance of the model was compared with five other optimized ANFIS models. ANFIS-GO showed outperformance compared with other models to predict milled surface characteristics. The root-mean-square deviation and determination coefficient of predicted data by ANFIS-GO compared with experimental ones are 0.002 and 0.911 for fractal dimension and 0.129 and 0.998 for surface roughness, respectively.

Therapeutic efficacy of vancomycin-loaded carbon fiber-reinforced polyetheretherketone hip stem for periprosthetic joint infection: A pilot study.

A carbon fiber-reinforced polyetheretherketone (CFR/PEEK) hip stem with a special antibiotic elution mechanism is under development to treat periprosthetic joint infection (PJI). The antibiotic elution characteristics of intramedullary implants were experimentally investigated, and the efficacy of revision surgery using a therapeutic stem in treating ovine PJI was examined. To evaluate elution characteristics, the intramedullary vancomycin-loaded CFR/PEEK cylindrical implants were inserted in the distal femur of nine sheep, and the vancomycin elution rate was measured at 2, 7, and 21 days. To evaluate therapeutic efficacy, the PJI model with staphylococcus aureus was attempted to create for five sheep. Moreover, the therapeutic vancomycin-loaded CFR/PEEK stem was implanted during one-stage revision surgery. Three weeks after revision surgery, the treatment efficacy was evaluated based on bacterial cultures and wound findings. In addition, the vancomycin elution rate from the stem was measured. On average, the cylindrical implants eluted approximately 70% vancomycin in 21 days. Of the five sheep attempting to create a PJI model, three were successfully infected with S. aureus as intended for verification of treatment efficacy. In all three joints, negative bacterial cultures and no purulence were observed 3 weeks after revision surgery. The vancomycin elution rates from the stems were >70%. Efficient elution of vancomycin was confirmed by the experimental implant inserted into the bone marrow and the stem in actual PJI treatment. Using a novel therapeutic stem with an antibiotic elution mechanism in one-stage revision surgery, successful treatment was demonstrated in all S. aureus-induced PJIs.

Biomechanical behavior of carbon fiber-reinforced polyetheretherketone as a dental implant material in implant-supported overdenture under mandibular trauma: A finite element analysis study.

Implant-supported overdentures are well-known and widely accepted treatment modality to increase retention which is a crucial factor for determining patient satisfaction. The placement of two implants in the anterior region can be selected as a first-line treatment in patients with the atrophic mandibular ridge. The purpose of this research was to assess the biomechanical effects of carbon fiber-reinforced polyetheretherketone (CFR-PEEK) implant-supported overdenture in the event of 2,000 N forefront trauma to an atrophic edentulous mandible by using the finite element analysis method. Three types of mandible models were simulated; the first one was an edentulous atrophic mandible model; in the second model, 3.5 × 11.5 mm CFR-PEEK implants; and in the third model, 4.3 × 11.5 mm CFR-PEEK implants were positioned in the region of the lateral incisor of the identical edentulous atrophic mandible. Maximum Von Misses stresses 979.261 MPa, 1,454.69 MPa, and 1,940.71 MPa and maximum principal stresses 1,112.74 MPa, 1,249.88 MPa, and 1,251.33 MPa have been detected at the condylar neck area and minimum principal stresses - 1,203.38 MPa, -1,503.21 MPa, and - 1,990.34 MPa have been recorded at the symphysis and corpus regions from M1 to M3, respectively. In addition, the M2 and M3 models showed low-stress distributions around the implant-bone interface, particularly where the implants were in contact with cancellous bone. The results showed that the insertion of different diameters of CFR-PEEK implants led to low and homogenous stress distribution all around the implant-bone interface and stresses transferred directly to the condylar neck areas. Therefore, it was observed that CRF-PEEK implants did not change the basic behavior of the mandibula in response to frontal stresses.

Dosimetric Impact of Radiolucent Carbon Fiber Hardware for Post-Operative Spine Stereotactic Body Radiation Therapy

The spine is the most common site of osseous metastases. In the non-operative setting, there is growing support for stereotactic body radiation therapy (SBRT) over conventional radiation therapy for improved pain relief and local control. Hybrid therapy consisting of separation surgery and post-operative SBRT is considered in patients with biomechanical instability and epidural cord compression. Surgery traditionally requires titanium (Ti) implants, which introduce artifacts on post-operative imaging in addition to increased uncertainty and beam attenuation. Use of radiolucent carbon fiber reinforced polyetheretherketone (CFR-PEEK) hardware has been shown to provide safe and comparable surgical outcomes as compared to Ti. Our primary objective is to assess the dosimetric impact of Ti versus carbon fiber implants in spine SBRT. Single institution retrospective series of post-operative spine SBRT from 2019-2020. Re-irradiation cases were excluded. The electronic medical record and treatment planning systems (TPS) were queried. Dosimetric analyses compared original Ti plans with reoptimized plans, replacing Ti hardware electronic density with carbon fiber. Maintaining clinical goals, dose calculations were performed in a treatment planning system using a collapsed cone algorithm. All treatments used step and shoot intensity modulated radiation therapy to avoid beam angles with significant metal along the beam path. Metallic artifacts were contoured and assigned the appropriate tissue density. A D'Agostino-Pearson test was used to assess data for normality. We used paired Student's t-tests to compare three dosimetric outcomes in the setting of Ti and carbon fiber implants. Planning target volume (PTV) coverage was represented by the volume receiving at least the prescribed dose (%), the maximum point dose (dmax, cGy) to the spinal cord planning risk volume (PRV, 2 mm margin), and the overall hot spot intensity (plan dmax). A series of 14 consecutive SBRT cases were evaluated (dose 27-30 Gy in 3-5 fractions). All dosimetric outcomes were normally distributed (p>0.05). We found a statistically significant difference in PTV coverage between the original SBRT treatment plans with Ti hardware (mean 85.1 ± 7.9%) and reoptimized carbon fiber hardware (87.3 ± 6.6%; p = 0.002). There was no significant difference in mean spinal cord PRV dmax between Ti and carbon fiber plans (1846 ± 483 cGy vs. 1842 ± 495 cGy; p>0.05). We observed a nonsignificant increase in mean overall dmax from 3932 ± 416 cGy in the Ti cohort to 4111 ± 906 cGy in the carbon fiber cohort (p>0.05). Carbon fiber implants provide a significant increase in SBRT target coverage, without impacting the overall plan and spinal cord PRV dmax in this retrospective series. In addition to improved post-operative imaging and reduced uncertainty, carbon fiber hardware may offer dosimetric advantages as compared to traditional Ti spinal implants, and warrants further investigation in a larger cohort.

Effect of carbon-fiber-reinforced polyetheretherketone on stress distribution in a redesigned tumor-type knee prosthesis: a finite element analysis.

Background: Surgery for bone tumors around the knee often involves extensive resection, making the subsequent prosthetic reconstruction challenging. While carbon fiber-reinforced polyetheretherketone (CF-PEEK) has been widely used in orthopedic implants, its application in tumor-type prosthesis is limited. This study aims to evaluate the feasibility of using 30wt% and 60wt% carbon fiber-reinforced polyetheretherketone (CF30-PEEK and CF60-PEEK) as materials for a redesigned tumor-type knee prosthesis through numerical analysis. Methods: A knee joint model based on CT data was created, and the resection and prosthetic reconstruction were simulated. Three finite element models of the prostheses, representing the initial and updated designs with CoCrMo and CFR-PEEK components, were constructed. Loading conditions during standing and squatting were simulated with forces of 700N and 2800N, respectively. Finite element analysis was used to analyze the von Mises stress and stability of all components for each prosthesis type. Results: After improvements in both material and design, the new Type 3 prosthesis showed significantly lower overall stress with stress being evenly distributed. Compared with the initial design, the maximum von Mises stress in Type 3 was reduced by 53.9% during standing and 74.2% during squatting. In the standing position, the maximum stress in the CF30-PEEK femoral component decreased by 57.3% compared with the initial design which was composed of CoCrMo, while the stress in the CF60-PEEK cardan shaft remained consistent. In the squatting position, the maximum stress in the femoral component decreased by 81.9%, and the stress in the cardan shaft decreased by 46.5%. Conclusion: The incorporation of CF30-PEEK effectively transmits forces and reduces stress concentration on the femoral component, while CF60-PEEK in the redesigned cardan shaft significantly reduces stress while maintaining stiffness. The redesigned prosthesis effectively conducts loading force and demonstrates favorable biomechanical characteristics, indicating the promising potential of utilizing CF30-PEEK and CF60-PEEK materials for tumor-type knee prostheses. The findings of this study could provide novel insights for the design and development of tumor-type knee prostheses.

Comparative study on machining performance of conventional and ultrasonic-assisted drilling of carbon fiber-reinforced polyetheretherketone composite

Comparative study on machining performance of conventional and ultrasonic-assisted drilling of carbon fiber-reinforced polyetheretherketone composite

In-house processing of carbon fiber-reinforced polyetheretherketone (CFR-PEEK) 3D printable filaments and fused filament fabrication-3D printing of CFR-PEEK parts

In-house processing of carbon fiber-reinforced polyetheretherketone (CFR-PEEK) 3D printable filaments and fused filament fabrication-3D printing of CFR-PEEK parts

Investigating the material removal mechanism and cutting performance in ultrasonic vibration-assisted milling of carbon fibre reinforced thermoplastic

Carbon fibre reinforced thermoplastic (CFRTP) has emerged as a sustainable alternative to carbon fibre reinforced plastic (CFRP) due to its improved reparability and recyclability. CFRTP, particularly carbon fibre reinforced polyetheretherketone (CF/PEEK), is a high-performance material known for its excellent mechanical, thermal, and corrosion resistance properties, making it well-suited for extreme environments in civil aviation equipment. However, machining processes such as milling often result in defects due to the material’s high toughness and anisotropic nature. This study aims to investigate the material removal mechanism in ultrasonic-assisted milling (UAM) of CF/PEEK and compare the effects of fibre cutting angle (θ) and milling processes on milling performance. To simulate the fibre fracture mechanisms under different θ, finite element analysis (FEA) is employed. The results reveal different fracture modes, including bending, bending-shear, compression, and compression-shear, at various θ. Additionally, UAM demonstrates lower cutting forces and temperatures compared to conventional milling (CM). Notably, UAM greatly improves surface quality by reducing burr height and facilitating chip evacuation, while also enhancing surface integrity by minimizing cavity defects and fibre pull-out phenomena. These findings contribute to the development of low-damage machining methods that aim to achieve higher accuracy in CFRTP.

Mechanical, microstructural and numerical investigations of 3D printed carbon fiber reinforced PEEK

In the frame of technology development, fused deposition modeling is adapted in this study to elaborate composite material from 20% short carbon fiber reinforced polyether ether ketone (CF/PEEK) filament. This printing technology has attached widespread intention as it provides a rapid prototyping parts with high performances in diverse fields. For this purpose, a set of experimental tensile and bending tests are carried out to focus on the effect of printing orientation on the mechanical properties of the designed samples. Three raster angles are considered in this investigation: 0°, ±45°, and 90°. The obtained results indicate that the printing orientation of 0°, which is parallel to the tensile loading path and perpendicular to the flexural one exhibits higher mechanical strength compared to the other orientations. Evolution of Young modulus, total elongation at failure, yield and ultimate strengths as well as deflection are also discussed. Experimental work is supported by numerical simulation and a good agreement is revealed. Microstructural analysis is performed in order to argue the observed mechanical behavior. Through the fractured section morphology, the effect of tensile loading on CF/PEEK microstructure, at various printing orientation is emphasized.

Comparative Study of the Tribological Properties of CFRPEEK, Stainless and Carbon Steel in High Water-Based Fluid

The advantageous physical and chemical properties of carbon-fiber-reinforced polyetheretherketone (CFRPEEK) make it a suitable friction pair for water hydraulic components. To explore the selection of friction pair materials, this paper investigated the tribological properties of CFRPEEK, stainless and carbon steel in water and high water-based fluids, and evaluated them using reciprocating friction and wear tester. After the test, the wear surface morphology of the contact surface was observed under an electron microscope. The results show that the degree of friction between specimens is dependent on the load and frequency. Meanwhile, both 316L and CFRPEEK have good tribological properties in both mediums. Microscope observation analysis showed that CFRPEEK surfaces easily absorb water to create a water film, thus improving its performance and reducing wear. Additionally, the friction between stainless and carbon steel in high water-base fluid will generate a lubricating film, the surface of which shows excellent tribological properties. The final conclusion was that the choice of material for plunger pair material depends on the medium, with 304-316L being more suitable for high water-based fluids, while CFRPEEK-316L is more suitable for water.